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1
Gratten, Jacob. "The molecular systematics, phylogeography and population genetics of Indo-Pacific Crocodylus /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17777.pdf.
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Martin, Jérémy Emiland. "Le crocodile de l’Allier : Diplocynodon, sa systématique, son écologie et sa place dans l’évolution des alligatoroïdes primitifs." Lyon 1, 2009. http://n2t.net/ark:/47881/m6n29v4v.
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Le genre Diplocynodon fut fondé par Pomel en 1847 sur la base de restes de crocodiliens découverts dans le Miocène inférieur de Saint-Gérand-le-Puy, dans l’Allier. Bien que la distribution stratigraphique de ce crocodilien soit étalée sur la majeure partie du Cénozoïque, son registre fossile est discontinu et ses relations de parenté au sein des crocodiles eusuchiens restent obscure. L’apport de nouveau matériel fossile, représenté soit par de nouveaux taxons ou soit par du matériel autorisant des révisions approfondies de taxons déjà connus, permet de caractériser l’évolution du genre Diplocynodon et des assemblages de crocodiliens depuis le Crétacé supérieur, période clef de l’émergence des crocodiliens modernes. Une clarification taxonomique au sein du genre Diplocynodon est apportée. Les analyses phylogénétiques de plusieurs taxons montrent que les alligatoroïdes ont occupé une place prépondérante au sein des faunes crocodiliennes d’Europe. La présence de Diplocynodon est attestée depuis l’Eocène basal jusqu’au Miocène moyen. Son aptitude à endurer les vicissitudes climatiques du Cénozoïque, particulièrement celle de la limite Eocène/Oligocène est remarquableIn this thesis, we study the thermal effects of meteoritical impacts and their contributions to core formation using numerical modeling. Meteoritical impacts lead to a local temperature increase function of the radius of the impacted body in a spherical region above the surface. A large impact on a small protoplanet lead to a thermal anomaly without significant melting. For large enough impactors, the thermal anomaly first flatens above the surface by isothermal advection and then cools by diffusion. The thickness of the thermal anomaly at the end of advection depends only on the radius and rheological parameters of the impacted body. After a large impact on a large undifferentiated protoplanet, the temperature increase can generate local melting and separation between heavy iron and light silicates. The iron sinks towards the center of impacted body and contributes to core formation. We develop models of thermal evolution of the metallic phase. The iron can undergo viscous heating while sinking through undifferentiated material. The temperature of the iron only increases for large enough metallic diapirs. This heating is function of the rheological parameters of the impacted body and depends mainly on viscosity contrasts involved in the dynamics
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Legendre, Lucas. "Les crocodiles sont-ils devenus secondairement ectothermes ? : étude paléohistologique." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066307/document.
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Les archosaures sont un clade de vertébrés comprenant les oiseaux, les crocodiliens, ainsi que de nombreux groupes fossiles. Ce groupe fait depuis plusieurs décennies l'objet d'un important débat parmi les paléontologues quant à l'évolution du thermométabolisme au sein de ses différentes lignées. L'hypothèse classique considère que seuls les oiseaux modernes sont endothermes, tandis que tous les autres archosaures sont ectothermes. L'histologie osseuse permet d'étudier plusieurs traits relatifs au thermométabolisme impossibles à mesurer sur des spécimens fossiles ; c'est pourquoi nous avons utilisé des caractères mesurés sur des coupes histologiques d'os longs.Nous nous sommes consacrés dans une première partie à une revue détaillée de la mesure du signal phylogénétique pour des caractères ostéohistologiques dans deux clades de vertébrés, ce qui nous a permis de mieux définir l'approche à suivre dans la construction de nos modèles prédictifs.Après une étude préliminaire consacrée à l'élaboration d'un modèle prédictif du taux de croissance osseuse, nous avons construit un modèle global capable de prédire directement le taux métabolique de nos spécimens fossiles. Nos résultats montrent que la majorité des archosaures de notre échantillonnage étaient endothermes. Cela implique que le dernier ancêtre commun des archosaures était probablement endotherme, et que les crocodiliens sont donc devenus secondairement ectothermes, probablement en réponse aux contraintes du milieu aquatique. Des études plus spécifiques sur la lignée des pseudosuchiens devraient permettre de déterminer à quel niveau de l'arbre phylogénétique s'est effectué le retour à cet état ectothermeArchosaurs are a clade of vertebrates that includes birds, crocodiles, and numerous fossil groups. This clade has been a matter of debate among paleontologists for decades concerning the evolution of thermometabolism in its different lineages. The classical hypothesis considers that only modern birds are true endotherms, whereas all other archosaurs are ectotherms. Bone histology allows to study several traits linked to bone growth rate and thermometabolism, otherwise impossible to estimate on fossil specimens; for this reason, we used characters measured on long bone histological sections.In the first section, we extensively reviewed the measure of phylogenetic signal for osteohistological features in two clades of vertebrates, which was then used to define the methodology for building our predictive models.After a preliminary study during which we built a predictive model for bone growth rate, we built a global model to predict the metabolic rate of our fossil specimens, using both histological features and phylogenetic information for each specimen. Our results show that a majority of archosaurs in our sample were endotherms. This implies that the last common ancestor of archosaurs was likely an endotherm, and that modern crocodiles became secondarily ectothermic, probably in response to their aquatic environment. More specific studies on pseudosuchians should allow to precisely identify the level of the phylogenetic tree at which the ectothermic state was acquired, as well as adaptive constraints behind this acquisition
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Legendre, Lucas. "Les crocodiles sont-ils devenus secondairement ectothermes ? : étude paléohistologique." Electronic Thesis or Diss., Paris 6, 2014. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2014PA066307.pdf.
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Les archosaures sont un clade de vertébrés comprenant les oiseaux, les crocodiliens, ainsi que de nombreux groupes fossiles. Ce groupe fait depuis plusieurs décennies l'objet d'un important débat parmi les paléontologues quant à l'évolution du thermométabolisme au sein de ses différentes lignées. L'hypothèse classique considère que seuls les oiseaux modernes sont endothermes, tandis que tous les autres archosaures sont ectothermes. L'histologie osseuse permet d'étudier plusieurs traits relatifs au thermométabolisme impossibles à mesurer sur des spécimens fossiles ; c'est pourquoi nous avons utilisé des caractères mesurés sur des coupes histologiques d'os longs.Nous nous sommes consacrés dans une première partie à une revue détaillée de la mesure du signal phylogénétique pour des caractères ostéohistologiques dans deux clades de vertébrés, ce qui nous a permis de mieux définir l'approche à suivre dans la construction de nos modèles prédictifs.Après une étude préliminaire consacrée à l'élaboration d'un modèle prédictif du taux de croissance osseuse, nous avons construit un modèle global capable de prédire directement le taux métabolique de nos spécimens fossiles. Nos résultats montrent que la majorité des archosaures de notre échantillonnage étaient endothermes. Cela implique que le dernier ancêtre commun des archosaures était probablement endotherme, et que les crocodiliens sont donc devenus secondairement ectothermes, probablement en réponse aux contraintes du milieu aquatique. Des études plus spécifiques sur la lignée des pseudosuchiens devraient permettre de déterminer à quel niveau de l'arbre phylogénétique s'est effectué le retour à cet état ectothermeArchosaurs are a clade of vertebrates that includes birds, crocodiles, and numerous fossil groups. This clade has been a matter of debate among paleontologists for decades concerning the evolution of thermometabolism in its different lineages. The classical hypothesis considers that only modern birds are true endotherms, whereas all other archosaurs are ectotherms. Bone histology allows to study several traits linked to bone growth rate and thermometabolism, otherwise impossible to estimate on fossil specimens; for this reason, we used characters measured on long bone histological sections.In the first section, we extensively reviewed the measure of phylogenetic signal for osteohistological features in two clades of vertebrates, which was then used to define the methodology for building our predictive models.After a preliminary study during which we built a predictive model for bone growth rate, we built a global model to predict the metabolic rate of our fossil specimens, using both histological features and phylogenetic information for each specimen. Our results show that a majority of archosaurs in our sample were endotherms. This implies that the last common ancestor of archosaurs was likely an endotherm, and that modern crocodiles became secondarily ectothermic, probably in response to their aquatic environment. More specific studies on pseudosuchians should allow to precisely identify the level of the phylogenetic tree at which the ectothermic state was acquired, as well as adaptive constraints behind this acquisition
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Rauschenberger, Richard Heath. "Developmental mortality in american alligators (alligator mississippiensis) exposed to organochlorine pesticides." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008223.
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Thesis (Ph.D.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 233 pages. Includes Vita. Includes bibliographical references.
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Cotroneo, Laurie Anne Spotila James R. "Population genetics and conservation of the American crocodile on the pacific coast of Costa Rica /." Philadelphia, Pa. : Drexel University, 2010. http://hdl.handle.net/1860/3311.
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Jamerlan, Mona Lisa. "Establishing mating systems by microsatellite analysis in declining saltwater crocodile (Crocodylus porosus) hatchling production at Edward River Crocodile Farm (Nth. Queensland) /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17070.pdf.
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Swan, Jennifer. "HABITAT AND COMMUNITY CHARACTERISTICS OF WILDLIFE RESCUED DURING THE EXPANSION OF THE PANAMA CANAL." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1168.
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Since the ceding of the Panamá Canal from the United States to the Republic of Panamá in 1999, human development has accelerated, resulting in the loss of tropical rainforest habitat and declines in wildlife populations. In 2007 this area of vast plant and wildlife diversity experience further loss of habitat as land clearing and excavation commenced for the Panamá Canal Third Locks Expansion Project. As one of the largest construction projects in the world, the potential impacts of the expansion prompted the Panama Canal Authority to work with a local non-governmental conservation organization to initiate a wildlife rescue and relocation operation to conserve wildlife in the affected areas. From 2007 to 2010, 896 wildlife rescue events occurred in 11 areas along the Canal; 806 of these individuals (90%) were successfully relocated to protected areas (n=749) or captivity (n=57). These wildlife rescue efforts were summarized, including human labor required, wildlife species composition, and conservation statuses according to the IUCN and CITES. Also quantified were wildlife dominance and biodiversity using the Simpson, Shannon, Berger-Parker, and Brillouin diversity indices, relative abundance of >100 Neotropical species, and habitat-abundance relationships for four focal species: Hoffman's two-toed sloth, Choloepus hoffmanni; brown-throated three-toed sloth, Bradypus variegatus; American crocodile, Crocodylus acutus; and common caiman, Caiman crocodilus. Relationships between diversity indices and habitat for the wildlife rescued during the wildlife rescue project were also analyzed. Results indicate the Panamá Canal Watershed to ii possess a diverse representation of Neotropical wildlife. Habitat-abundance relationships of focal species suggest two-toed sloth numbers increased as the edge of secondary forest decreased and number of three-toed sloths increased as total landscape area of agriculture decreased. Crocodile populations increased as number of patches on the landscape and mean patch size of secondary forest decreased, and caiman numbers increased as the edge density of secondary forests decreased and mean patch size of agriculture increased. Diversity-habitat relationships revealed wildlife diversity increased with heterogeneous secondary forest landscape consisting of less edge. This project provides rare insights into wildlife rescue operations and wildlife-habitat relationships for Neotropical wildlife species that will be useful for a range of conservation efforts. Additionally, this research provides updated population assessments for many of the species included in the research, especially the focal species, in which a need for them has been stressed in the conservation literature.
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Vignaud, Patrick. "Les thalattosuchia, crocodiles marins du mésozoïque : systématique phylogénétique, paléoécologie, biochronologie et implications paléogéographiques." Poitiers, 1995. http://www.theses.fr/1995POIT2272.
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Les thalattosuchia, crocodiles marins du mesozoique, sont connus dans les sediments depuis le debut du xixeme siecle. Le nombre plethorique d'especes creees (plus de 190) nous a amene a mettre en doute la validite de certaines. L'absence de caracteres diagnosiques clairement identifies ne permettait pas de preciser les relations phylogenetiques. L'etude synthetique de la biologie et de l'eco-ethologie des crocodiles actuels permet de mieux apprehender les phenomenes associes aux variations intraspecifiques. L'anatomie du complexe de la manducation et la croissance ontogenique des differentes structures craniennes sont analysees et detaillees. L'analyse morphologique des caracteres des thalattosuchia est essentiellement basee sur le materiel du callovien de la region de poitiers qui se caracterise par la precision de sa datation biochronologique et par son remarquable etat de conservation. L'etude biometrique et graphique est effectuee a l'aide de la quasi-totalite des cranes decouverts en europe. Ces analyses permettent de definir des caracteres diagnosiques puis de les tester grace a la connaissance des variations intraspecifiques chez les crocodiles actuels. Les modalites de la croissance du crane des thalattosuchia sont precisees. De nouvelles relations phylogenetiques sont proposees puis discutees. De nouveaux taxons sont crees, permettant ainsi a la systematique de mieux refleter la biodiversite de ces crocodiles marins. Un inventaire de toutes les decouvertes de thalattosuchia est etabli, tenant compte a la fois de la systematique, de la paleogeographie et de l'age des gisements. La correlation biochronologique des principales formations est proposee. Les capacites de dispersions sont precisees pour chacune des deux super-familles: teleosauroidea et metriorhynchoidea. Ces nouvelles hypotheses permettent d'apporter d'importantes precisions sur l'evolution de la paleogeographie durant le jurassique
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Beyeler, Patrick Marcel. "Protein requirements of juvenile Nile crocodiles (Crocodylus niloticus) in an intensive production system." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/29554.
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The objective of this study was to determine the dietary protein requirements of the Nile crocodile (Crocodylus niloticus) between the ages of 5 – 8 months, and to compare the results with documented protein requirements of the American alligator (Alligator mississippiensis). This was achieved by feeding the crocodiles 4 diets with varying amounts of crude protein (CP), including 62%, 56.6%, 51.6% and 46%. All four diets were iso-energetic with a metabolisable energy to protein ratio of 25.85KJ/g. The highest protein diet contained 44% raw minced chicken and 46.9% fish meal with minimal contribution (of 6.4%) made from vegetable protein sources (full fat soya). The lowest protein diet was made up of a majority of vegetable protein (30% soya bean oilcake, 9.8% full fat soya and 17.2% maize meal) and some contribution from protein of animal origin (4.3% carcass meal and 35% fish meal). This study was carried out for 12 weeks during the crocodiles first year of life. Body mass, total body length, head length and snout to vent length were measured five times at 3 weekly intervals. Twenty representative crocodiles in a pen of 200 were individually tagged for the duration of the trial. As there were 3 replicates for each of the 4 treatment diets, 240 crocodiles in 12 pens were tagged. During the early phase of the study, it was observed that crocodiles on the 46% CP treatment diet were not performing well, and that most of the crocodiles on this diet were losing mass. This treatment diet was discontinued at 9 weeks into the trial for both financial and ethical reasons. The remaining three diets were tested for the full 12 weeks. Chromium oxide was mixed into the diets at two time periods during the trial to determine the protein, energy and dry matter digestibility. It was determined that the 46%, the 51.6%, the 56.6% and the 62% CP diets had a digestible protein (DP) content of 246.44 g/kg, 294.80 g/kg, 381.32 g/kg and 468.65 g/kg and a digestibility coefficient of 53.50%, 57.00%, 69.15% and 75.65% respectively. Performance of crocodiles on the 46% CP treatment diet was found to be lower in all measurement categories than crocodiles on the three higher protein diets. However, crocodiles on the 62% CP treatment diet outperformed all the crocodiles (on all measurement criteria) on the lower protein diets. The poor performance of crocodiles on the lowest protein diet correlates with previous research indicating that crocodilians are unable to perform optimally when the majority of the diet’s protein is made up of vegetable protein sources. It was determined that juvenile American alligators would grow at optimal levels when the diet contained a DP content of 450 g/kg. As the Nile crocodiles in this study performed the best when the diet contained a DP value of 468.65 g/kg, it was concluded that juvenile Nile crocodiles have the same range of protein requirements as that determined for juvenile American alligators.Dissertation (MSc(Agric))--University of Pretoria, 2011.
Animal and Wildlife Sciences
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Vasse, Denis. "Systematique des crocodiles du cretace superieur et du paleogene d'europe. Aspects paleobiogeographique et paleoecologique." Paris 6, 1993. http://www.theses.fr/1993PA066481.
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La liste des crocodiliens du cretace superieur et du paleogene d'europe, mise a jour et revisee permet de se faire une idee de ces faunes crocodiliennes. Un inventaire des gisements ayant livre des restes de crocodiles est etabli, en precisant la nature de ces restes quand cela a ete possible, permettant de se rendre compte de la repartition de ces gisements et de l'extension stratigraphique des taxons identifies. La connaissance des crocodiliens du paleocene est amelioree. Les origines et les relations phyletiques sont envisagees. On peut emettre quelques hypotheses paleobiogeographiques, et les comparer aux donnees fournies par d'autres groupes. Certaines hypotheses sont en accord avec ce qui est etabli, d'autres mettent en jeu des relations paleogeographiques moins evidentes. Sur la base de ces listes une analyse de diversite est etablie, qui permet de suivre l'evolution des faunes de crocodiliens dans le temps considere ici. Les courbes de diversite globales et par types ecologiques, et celles des taux de disparitions et d'apparitions etablies pour les crocodiliens europeens sont comparees a celles etablies pour l'ensemble du monde. Differents points de vue sont pris pour expliquer les phenomenes mis en evidence, qui sont replaces dans un contexte plus general pour les deux crises
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Pfitzer, Silke. "Physiological parameters of farmed Nile crocodiles (Crocodylus niloticus) captured manually and by electrical immobilisation." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/46106.
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During the past 15 years crocodile farming has become more important and sophisticated all over the world. In South Africa there are currently an estimated one million Nile crocodiles (Crocodylus niloticus) on commercial farms, mostly for leather production. The management, especially of crocodiles that are close to slaughter, is very intensive as the skins of these animals have to be in immaculate condition to achieve good prices on the international markets. In this regard, the electric stunner is often used on a daily basis on most farms in South Africa to safely handle crocodiles. However, this technique (electrical immobilisation) has only been scientifically evaluated in the Australian saltwater crocodile (C. porosus). As crocodilian species might react differently to the electrical immobilisation procedure, the aim of the project was to compare certain physiological parameters of Nile crocodiles captured by either electrical immobilisation (stunning) or captured manually by noosing. This study was conducted during the summer of 2012 on a commercial crocodile farm near Pongola, South Africa.
In total 45 crocodiles were used of which 23 crocodiles were captured by electrical immobilisation and 22 by means of noosing. Physiological parameters chosen for monitoring were serum corticosterone, blood lactate, blood glucose, as well as alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST) and creatinine kinase (CK). The concentrations and activities of these parameters were determined in blood samples collected immediately after capture by the two methods. Animals were then tied and blind-folded and kept in a quiet place. Four hours later blood samples were collected again from each animal to monitor changes in concentrations and activities of these parameters. In all cases the time was recorded that it took to capture each animal. In addition, total handling time until blood collection was also recorded on an individual basis. Our results indicate that although corticosterone increased greatly within the four hour interval in both groups, there was no difference (p> 0.05) between the two methods of capture. Lactate did not increase significantly within the four hour period in both groups, but was higher when animals were noosed. Glucose concentrations rose within four hours, but no significant differences could be detected between the two capture methods. While ALT and ALP did not show any clear trend, increased activities were detected for AST and CK in the four hour period after capture. Both, AST and CK levels were higher in noosed animals. Noosing a crocodile took longer to restrain the animal when compared to the stunning method. On average stunning took 118 seconds from start of capture until an animal was under control while noosing took 186 seconds per animal. As a consequence the noosed animals struggle for a longer time, which most probably caused exhaustion and muscle damage; explaining the higher levels of blood lactate, AST and CK. One helper was injured (bite wound) trying to control a crocodiles using the noose method. Electrical immobilisation is therefore considered to be the better option for commercial farms, from a physiological perspective, as well as an animal welfare and human safety viewpoint.Dissertation (MMedVet)--University of Pretoria, 2013.
tm2015
Production Animal Studies
MMedVet
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Hughes, Sandrine. "Évolution et structure des génomes de reptiles." Lyon 1, 2000. http://www.theses.fr/2000LYO10143.
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Aust, Patrick Welby. "The ecology, conservation and management of Nile crocodiles Crocodylus niloticus in a human dominated landscape." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/5297.
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Nile crocodiles were extensively persecuted throughout much of the 20th century. The extinction of the species was only averted by the timely intervention of conservationists and by the beginning of the 21st century most populations had recovered. Many of the conservation measures designed to curb the original extinction threats remain unchanged and are now perceived by some to be outdated. The recovery of Nile crocodile populations has been accompanied by rapid human population growth and demands for freshwater resources. This phenomenon has resulted in a converging conflict crisis between Nile crocodiles and humans. The aim of this thesis is to (a) quantify the extent of human crocodile conflict (HCC) and (b) establish the implications for conservation and development. (a)The extent of HCC was assessed by (i) analysing losses incurred by local communities (ii) analysing the demographics of crocodiles in relation to human activities (iii) analysing the relationship between humans and crocodile prey species. Nile crocodiles pose a substantial threat to subsistence livelihoods whilst rural communities have significant negative impacts on crocodiles (i) Estimates suggest an annual loss of between ~255 and ~6864 cattle per year and damage to an estimated 71500 fishing nets per year in North Eastern Namibia. (ii) All crocodile size classes showed a negative relationship with people at the inter- and intra-river levels. (iii) Crocodile prey species showed a significant negative spatial relationship with cattle. (b) Conservation and management implications were assessed by estimating the spatial patterns of HCC explanatory variables on a continental scale. Protected areas are important for crocodile conservation. The use of crocodile habitat as boundaries for protected areas raises important questions relating to HCC.
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Van, Wilpe Erna. "Liver and gallbladder morphology of the juvenile Nile crocodile, Crocodylus niloticus (Laurenti, 1768)." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/29730.
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This investigation illustrates the topography, gross anatomy, histology and ultrastructure of the liver and gallbladder of the Nile crocodile in order to fill the gap that exists in the literature regarding this important crocodilian. For the topographical and macroscopical descriptions the livers and gallbladders were obtained from the carcasses of slaughtered juvenile Nile crocodiles. Perfusion and immersion fixation of tissues for histology and transmission electron microscopy were performed on juvenile Nile crocodiles donated to the university. Published descriptions of other vertebrates were inevitably relied upon for comparison due to the lack of information on these two organs of the Nile crocodile. The liver was located in its own coelomic cavity with the post-pulmonary and the post-hepatic membranes intimately associated with the cranial and caudal surfaces of the bi-lobed liver respectively. The right lobe was larger than the left lobe and they were located at the level of the third to seventh intercostal spaces with their extremities extending to the ninth intercostal space. The triangular shaped liver lobes were joined dorso-medially by a narrow isthmus consisting of liver tissue. The liver was covered by Glisson’s capsule. Central veins, sinusoids and portal tracts were distributed haphazardly with no visible lobulation. The parenchymal component occupied the largest part of the liver and was formed by anastomosing and branching cell cords consisting of two-cell-thick plates in the longitudinal sectional plane and at least five hepatocytes in the cross-sectional plane. Central bile canaliculi contained microvilli originating from apical hepatocyte surfaces and were sealed off by junctional complexes. Hemosiderin granules, bile pigments, melanin pigments, lipid droplets, cholesterol ester slits and glycogen granules were observed in addition to the normal hepatic cytoplasmic organelles. Non-parenchymal cells consisted of endothelial cells, Kupffer cells, stellate cells and pit cells localized in and around the angular sinusoids. The space of Disse existed between endothelial cells and the base of the hepatocytes which was lined by microvilli. Endothelial cells were flat cells with long fenestrated cytoplasmic extensions that lined the sinusoidal wall and contained numerous endocytotic vesicles and many lysosomes. Pleomorphic Kupffer cells were located in the sinusoidal lumen, in the space of Disse and within groups of hepatocytes. They were often situated between groups of hepatocytes, connecting two adjacent sinusoids. Large phagosomes were present in the Kupffer cells and contained a combination of melanin and hemosiderin granules as well as ceroid. Phagocytosis of apoptotic and dying cells was evident. Conspicuous groups of membrane-bound tubular organelles with a filamentous or crystalline interior were present in the Kupffer cells. Stellate cells occupied a subendothelial position in the space of Disse and contained prominent lipid droplets that indented the nuclei. A solitary cilium was infrequently found projecting into the space of Disse. Myofibroblastic cells were found in the same region as stellate cells. Pit cells with indented eccentric nuclei were found in the sinusoidal lumen and in close contact with endothelial and Kupffer cells. Numerous small electron-dense membrane-bound cytoplasmic granules were present. Occasional intercalated cells resembling lymphocytes were seen in the space of Disse and forming part of the groups of hepatocytes. Glisson’s capsule extended collagenous trabeculae into the parenchymal interior and variably sized trabeculae randomly traversed the liver tissue. Portal tracts were enmeshed by a collagenous network that contained fibroblasts, lymphocytes, plasma cells and phagocytes. Portal triads consisted of branches of the portal vein, hepatic artery and bile duct with lymphatic vessels sometimes in accompaniment. Reticular fibres were positioned around hepatocyte tubules and a basal lamina supported the hepatocytes adjacent to Glisson’s capsule. Occasional unmyelinated nerve axons were present. The isthmus contained liver tissue with similar parenchymal and a non-parenchymal components. Three anatomical zones were identified in the pouch-like gallbladder that was attached caudally to the right liver lobe in the dorso-medial region. The gallbladder wall consisted of pseudostratified columnar epithelium, a lamina propria, a muscularis externa and a serosal layer. The accumulation of apical secretory granules, apical bulging, exocytosis of mucous granules and the desquamation of the apical portions of the epithelial cells into the lumen indicated different stages of the mucus secretory cycle. CopyrightDissertation (MSc)--University of Pretoria, 2012.
Anatomy and Physiology
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Wallace, Kevin Michael. "The feeding ecology of yearling, juvenile and sub-adult Nile crocodiles, Crocodylus niloticus, in the Okavango Delta, Botswana." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1300.
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Olsson, Annabelle. "Investigation into developing reliable immobilisation protocol for use under varying environmental temperatures in estuarine and Australian freshwater crocodiles." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10446.
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The objective of this research was to determine a set of commonly available chemical restraint options which produced safe, reliable and repeatable immobilisation for estuarine crocodiles (Crocodylus porosus) under varying environmental conditions to enable any procedure to be undertaken safely and humanely. This study has shown that the site of an intramuscular (IM) injection of medetomidine and alfaxalone did impact the onset, duration and character of immobilisation, with the fore limb musculature being the preferred site of injection. Medetomidine as a sole agent was effective and even at low temperatures the drug was able to be antagonised using atipamezole. At optimal temperatures the immobilisation it produced was consistent, reliable and repeatable. It also showed that it is able to be scaled allometrically and used successfully on animals between 5 kg and 400 kg in body weight. Atipamezole consistently and reliably antagonised the immobilisation regardless of temperature. Alfaxalone was included in the study to investigate the effect of temperature on the duration and quality of immobilisation. The study using midazolam demonstrated its benefit in minimising changes to stress indicators such as lactate, pH and bicarbonate compared with physically restrained animals. As a result of this research, medetomidine has become the drug of choice for immobilisation of estuarine crocodiles for short term restraint or minor procedures. The other important contribution this research has made to the future of crocodile immobilisation is to demonstrate that temperature has a predictable effect on performance of drugs, but that below the broad preferred range for the species drugs perform very poorly. This research has improved the safety and welfare of immobilisation of crocodiles.
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Soehner, Jennifer R. "Why is There Such a High Concentration of Vertebrate Remains Within a Bone-bed Along Clapp Creek, Williamsburg County, South Carolina?" Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1346191790.
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Ganswindt, Stefanie Birgit. "Non-invasive assessment of adrenocortical function in captive Nile crocodiles (Crocodylus niloticus) and its relation to housing conditions." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/25143.
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The Nile crocodile (Crocodylus niloticus) is one of 23 extant crocodilian species, and has been farmed in southern Africa since the 1960s. For the crocodile industry, chronic stress and its often negative consequences are a concern, since stressors can negatively affect animal production as well as the health of the crocodiles. When confronted with a stressor, an individual displays a stress response consisting of a suite of physiological and behavioral alterations to cope with the challenge. So far, however, no method for determining stress-related responses in Nile crocodiles has been established. In other crocodilians, the assessment of physiological responses to stress, like the related alterations in glucocorticoid concentrations, has already been done, but only by using an invasive approach, with the disadvantage of a possible handling-induced stress response. By establishing a non-invasive technique to monitor glucocorticoid levels in captive Nile crocodiles based on faecal hormone analysis, this study not only made an important contribution to a better understanding of stress and related hormonal changes in Nile crocodiles, but also provided a solid basis for developing similar non-invasive tools to collect information on the level of stress experienced by other crocodilians. Specifically the study aimed 1) to assess adrenocortical activity in Nile crocodiles by measuring faecal glucocorticoid metabolite (FGM) concentrations, and 2) to characterise changes in FGM levels in captive Nile crocodiles in relation to different housing conditions. An adrenocorticotropic hormone (ACTH) challenge was performed on 10 sub-adult crocodiles at Le Croc crocodile farm, South Africa, resulting in serum corticosterone levels of up to ~1200 %, 1 - 5 hours post-injection, above the pre-injection levels. An additional 8 individuals were exposed to electric immobilisation and handling only (control group), which resulted in a 20 – 2700 % elevation in serum corticosterone concentrations, indicating that handling was already a sufficient stressor. FGM levels in 3 singly housed animals (2 ACTH challenge; 1 handling only) reached peaks of 136 – 380 % above pre-injection levels at about 7 to 15 days following treatment, demonstrating that non-invasive hormone monitoring can be used for assessing adrenocortical function in captive Nile crocodiles based on FGM analysis. By assessing the impact of group size (n = 1, 2, or 4 individuals) on FGM levels, highest mean hormone values were found in the paired animals. A possible explanation for this finding could be that the necessary re-grouping for the study resulted in an unstable group composition, especially for the paired animals of similar size, which is reflected in comparable higher FGM concentrations. However, future research would be necessary to investigate this potential relationship in more detail. My study created opportunities to improve the management and welfare of farmed crocodiles in terms of more appropriate housing conditions and husbandry for these animals. Finally, the now established non-invasive method for monitoring adrenocortical function in Nile crocodiles provides a solid basis for further studies focusing on monitoring factors influencing adrenocortical function in populations of Nile crocodiles in the wild.Dissertation (MSc)--University of Pretoria, 2012.
Paraclinical Sciences
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Botha, Petrus Johannes. "The distribution, conservation status and blood biochemistry of Nile crocodiles in the Olifants river system, Mpumalanga, South Africa." Thesis, University of Pretoria, 2011. http://hdl.handle.net/2263/25717.
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The outlook for Nile crocodiles in the Olifants River does not look optimistic. Since the increase in capacity of the Loskop and Flag Boshielo Dams, the crocodile population was left with no basking or nesting sites and has declined over the past 30 years. Shortly after the Massingire Dam in Moçambique filled to full capacity an estimated 160 crocodiles died in the Olifants River Gorge, a couple of kilometres upstream from the dam. The Olifants River is acknowledged by many experts as one of the most polluted rivers in South Africa and acid mine drainage, industrial pollution and untreated sewage in the river are all contributing to the poor water quality of the river. Further, the Department of Water Affairs and Forestry acknowledge that water demand already exceeds their capacity to supply and that the situation will worsen considerably in the near future. Aerial surveys of Nile crocodiles in the Olifants River was carried out during December 2005 and November 2009. An average total population of 714 Nile crocodiles were counted and corrected to an estimated 1140 individual crocodiles to eliminate the effects of undercounting. The Kruger National Park and specifically the area of the Olifants River Gorge was found to be one of the preferred habitat areas for crocodiles in the Olifants River as was the Flag Boshielo Dam, the area between the Blyde River and the western boundary of the Kruger National Park and the Olifants River between the Loskop Dam and the Flag Boshielo Dam. Repeated nesting in areas such as the Kruger National Park, the Flag Boshielo Dam and the Olifants River between the Loskop Dam and the Flag Boshielo Dam confirmed that these areas are critically important to the nesting success of Nile crocodiles in the Olifants River. The Elands River was confirmed as an important refuge area for Nile crocodiles in the Groblersdal-Flag Boshielo Dam area of the Olifants River. Surveys revealed an estimated total of only 15 crocodiles in the Loskop Dam and confirmed that no crocodiles in the large (2.1 - 4.0m TL) and very large size class (>4.0m TL) are currently present in the population. Blood biochemistry results indicate that the Olifants River Nile crocodile population probably suffers from chronic inflammation (especially in the Loskop Dam and Olifants River Gorge populations), infectious disease (particularly in the Loskop Dam population but all other sites also showed elevated values), possible inadequate diet and malnutrition (especially during the pansteatitis outbreak of August/September 2008) and are suffering serious immune problems in the Olifants River Gorge. A conservation and management plan is suggested which identifies threats to the continued existence of a viable Nile crocodile population in the Olifants River. Finally, it is suggested that the conservation status and risk of extinction of Nile crocodiles in the Olifants River be upgraded to the Endangered category since it currently complies to the following criteria; EN A2abce; C2a(i) published in the IUCN Red List Categories and Criteria Version 3.1 (IUCN, 2001).Thesis (PhD)--University of Pretoria, 2011.
Centre for Wildlife Management
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Grobler, Miemie. "The use of an inactivated vaccine in farmed Nile Crocodiles (Crocodylus Niloticus) for the control of Mycoplasma Crocodyli infection." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/26217.
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Since the first report of Mycoplasma-associated polyarthritis in farmed Nile crocodiles in 1995, the disease has spread across Zimbabwe and South Africa and has resulted in significant economic losses on infected farms. Due to poor response to antimicrobial treatment and frequent relapses, the use of an autogenous vaccine to manage disease outbreaks was evaluated. Two previous trials had been performed with a similar vaccine and the results suggested that the vaccine could be effective in alleviating disease, although the numbers of animals were limited in both. This trial aimed to evaluate an inactivated, alum-adjuvanted M. crocodyli whole-cell vaccine in a large group of yearling crocodiles under field conditions on a farm in Zimbabwe where repeated M. crocodyli outbreaks have been reported. The safety of the vaccine was assessed by administrating the vaccine intraperitoneally to a subset of crocodiles. No adverse clinical reactions were observed in any of these crocodiles. A group of two thousand two hundred crocodiles received two intramuscular vaccinations four weeks apart in the autumn of 2011, while another group of two thousand two hundred crocodiles served as unvaccinated controls. Serum was collected from a subset of the vaccinated and unvaccinated crocodiles at different time-points before and after vaccination to evaluate the humoral response to vaccination. Latex slide agglutination tests (LAT) were performed on all samples and positive samples were titrated with the latex slide agglutination test and metabolism inhibition assay. A low percentage of sera were positive with serological tests done prior to vaccination, suggesting either circulating Mycoplasma or maternal immunity. Statistically significant increase in sero-positivity was detected with LAT four weeks after primary vaccination, although the titre remained low. Six weeks after the booster vaccination the percentage seropositive vaccinated crocodiles had decreased and there were no statistically significant difference between the percentage seropositive vaccinated and unvaccinated crocodiles. A significant outbreak of Mycoplasma-like polyarthritis was encountered 6 months after vaccination, in October 2011. Both vaccinated and unvaccinated crocodiles were affected. Serum samples from different subsets of crocodiles were collected and evaluated similar to the vaccine trial. The results indicated that a similar rate of sero-positivity was present in all crocodiles, irrespective of vaccination- or disease status Sera collected during this trial was used to evaluate the performance of the latex slide agglutination assay compared to the metabolism inhibition assay (“Gold standard” assay), as the performance of the LAT had not been evaluated previously. The calculated diagnostic sensitivity was 72%, diagnostic specificity was 32%, the predictive value of the positive test was 36% while the predictive value of the negative test was 69%. This trial indicated that the autogenous, inactivated, alum-adjuvanted, whole-cell vaccine against M. crocodyli was not able to protect farmed Nile crocodiles on an infected farm against clinical Mycoplasma-associated polyarthritis. It was also found that the latex slide agglutination assay could be useful as a robust, pen-side assay to evaluate exposure to M. crocodyli, although other assays, such as PCR, bacterial culture or growth inhibition assays, has to be performed to confirm the presence of disease.Dissertation (MSc)--University of Pretoria, 2012.
Veterinary Tropical Diseases
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Booyens, Paul Lodewyk. "Pollutants associated with mass mortality of Nile crocodiles (Crocodylus niloticus) in the Kruger National Park, South Africa / P.L. Booyens." Thesis, North-West University, 2011. http://hdl.handle.net/10394/5564.
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The first of a series of mass mortalities of Nile crocodiles in the Olifants and Letaba rivers in the Kruger National Park (KNP) was reported in the winter of 2008. The present study investigated the levels and possible effects on eggshell thickness of inorganic elements and organic pollutants in Nile crocodile eggs from these rivers, and comparing them with eggs from a reference crocodile farm and a reference dam inside the KNP.
The egg contents were analyzed for chlorinated organic compounds and brominated flame retardants. Eggshells and egg contents were analyzed for inorganic elements.
The elemental concentrations in the eggshells and contents were low when compared with previous studies. The highest concentrations were found in the eggs from the reference crocodile farm. The eggs from the reference dam and the crocodile farm had thicker shells, and the eggs from the Olifants and Letaba rivers had thinner shells.
Not all eggs in a female develop at the same rate, while eggshell formation presumably occurs at the same time for all eggs. As a result, the elemental profile of egg contents may differ between eggs of the same clutch, but less so for the shells. Weak or no associations were found between the elemental concentrations of the content and eggshells and eggshell thinning. A possible organic pollutant–induced eggshell thinning effect was found.
The compounds found were not at levels that could have caused the mortalities, but may affect the sex ratios through endocrine disruption. Further studies are therefore required.Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
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Bathily, Naye. "La légende comme genre dans la littérature orale africaine : étude comparée de légendes de crocodiles le long du fleuve Sénégal." Paris 13, 2008. http://www.theses.fr/2008PA131029.
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Cette thèse s’inscrit dans la grande tradition des études africaines. En relation avec la problématique du genre, elle pose la question de la reconnaissance, des différents modes de repérage de la légende comme genre dans le panorama littéraire soninké. Une question qui se pose aussi à travers toute la littérature orale Africaine. Reconnue comme type de discours, car remplissant une fonction esthétique et sociale, la légende est cependant victime d’une forme de confusion avec les autres genres. Elle est tour à tour assimilée au conte, au mythe ou à la fable et ne jouirait d’aucun champ d’études définies contrairement aux autres formes de l’oralité. Par une double approche sur le plan théorique et sur plan pratique, les travaux ont tenté de cerner cette pratique littéraire, de faire émerger ses caractéristiques dans le contexte soninké marqué par une grande originalité des récits du fleuve. Un corpus est constitué, il compte plusieurs récits inédits qui ont été collectés dans les villages le long du fleuve Sénégal puis analysés. Le crocodile ressort comme un animal emblématique. Prédateur ou génie tutélaire, il est au cœur des préoccupations et nourrit l’imaginaire des populations riveraines. L’étude de ces types de récits permet de mieux placer le genre dans le système et dans la chronologie littéraire soninké. Entre le conte, le mythe, l’épopée et la rumeur, la légende est à la croisée de tous les traits morphologiques des autres formes littéraires. Elle émerge dans une spécificité fascinante et pose au delà de toutes autres approches, la question de l’évolution des genres en littérature orale africaineIn the tradition of other African studies, the present thesis is about the acknowledgement of the legend and its different ways of spotting it as a kind in the Soninke literature panorama, a raised question through all the African oral literature. Though already acknowledged as a sort of speech the legend fulfils an aesthetic and social role. Nevertheless, it is often confused and assimilated to with other kinds of literature such as the tale, the myth and the fable. The legend hasn’t got yet a defined domain unlike the other forms of oral literature. Both a theoretical and a practical approach were used to close in on the legend and to bring out its characteristics in the Soninke context which is marked by the river narrations. I established and analysed a corpus composed of unheard recitals collected in the villages alongside the Senegal River. It revealed the crocodile as a highly symbolic animal. It is the matter of all concerns either as a predator or a tutelary guardian (demigod?) and it nourishes the river side populations’ imaginary. Studying these recitals allowed me to set the legend into the system as well as in the chronology of Soninke literature. The legend is a hybrid of morphological traits of the tale, myth, epic and urban legend. It developed a fascinating specificity and at the same time rising the question of the evolution of kinds in African oral literature, beyond any other approach
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Merz, Sharon. "'Crocodiles are the souls of the community' : an analysis of human-animal relations in northwestern Benin and its ontological implications." Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/32861.
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In this thesis I explore human-animal relations amongst the Bebelibe of the Commune of Cobly, in the northwest of the Republic of Benin, West Africa, with a focus on how they relate to their tikedimɔmɔnte (true totem(s), literally “interdict(s)-true”). I start with an historical review of totemism, the debates it generated and how these contributed to the recent ontological turn in anthropology. I then explore the theoretical ideas I use for my analysis, which include “presencing” and the “ontological penumbra” (J. Merz 2017b; J. Merz and S. Merz 2017). Presencing builds on semiotics by explaining how people make meaning present through their engagement in and with the world around them, whilst ontological penumbras are the shadowy spaces of limbo that affect our whole being and that people need to negotiate as part of making sense of their engagement with the world. As part of these theoretical frameworks, I examine the “onton”, as introduced by Johannes Merz (2017b). Ontons are experiential, agentive and relational entities that are the result of presencing processes. Ontons, however, cannot be divided into representations (signifiers) and represented (signified) as signs can. An engagement in the world between different entities in an ontonic and thus nonrepresentational sense necessitates my introducing further notions including shared “ontonity” (instead of shared humanity) and “ontonhood” (rather than personhood). I demonstrate how these theoretical ideas work with reference to human-animal relations primarily amongst the Bebelibe in the Commune of Cobly. In order to do this, I provide an in-depth, “thick description” (Geertz 1973) ethnography that explores how people perceive and relate to animals through hunting, domestication, attitudes to eating meat, animal commodification, reincarnation, shapeshifting and totemism. As part of my analysis I also examine the impact of Christianity on human-animal relations by exploring several incidents involving Christians and their tikedimɔmɔnte.
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Romanelli, Pedro Fernando. "Propriedades tecnologicas da carne do jacare do Pantanal Caiman Crocodilus Yocare (Daudin, 1802) (Reptilia, Crocodilia)." [s.n.], 1995. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255351.
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Orientador: Pedro Eduardo de FelicioTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O objetivo deste trabalho foi avaliar o potencial do jacaré do pantanal Caiman crocodilus yacare (DAUDIN, 1802) em fornecer carne, bem como o conhecimento de algumas características químicas e tecnológicas de sua carne para ser uma possível alternativa de aproveitamento, no processamento e/ou consumo humano. Iniciou-se os estudos, com medidas para avaliar os aspectos quantitativos do animal através da composição corporal e da carcaça. Na composição corporal foi possível conhecer o percentual de ocupação no animal dos quatro cortes do segmento corporal: cabeça, tronco, cauda e membros. Na composição da carcaça, através da desossa manual, separaram-se os músculos e ossos, para calcular o percentual de cada componente. Desses estudos verificou-se nos 2 grupos de animais analisados, ser a cauda o corte com melhor rendimento muscular, com uma relação músculo / osso que variou de 7,5 - 9,5, seguido pelos membros com valores de 3,6 - 3,9 e o tronco com variação de 2,8 - 3,4. As mudanças "post mortem" foram acompanhadas com medidas da degradação anaeróbica do glicogênio e da curva de pH. Os resultados mostraram que nas primeiras 20 - 25 horas pós-abate, ocorreu 80 - 85% da degradação do glicogênio, e o pH inicial de 6,6 - 6,7 abaixou para 5,5 - 5,7 após 35 - 40 horas. A estabilidade da carne durante o armazenamento foi avaliada por medidas do Nitrogênio Volátil Total (N. V. T.) quando armazenado em temperatura de resfriamento (5-7°C), e pelo acompanhamento das alterações fisico-químicas quando armazenadas sob congelamento (-18°C). Neste caso, determinou-se as medidas de índice de acidez (I.A.), número de T.B.R.S. e mudanças de pH e ao longo do tempo de armazenamento. Verificou-se que sob refrigeração, a carne suporta de 3 a 4 dias, sem sinais de rejeição sensorial. No armazenamento a -18°C ao longo de 120-180 dias, observou-se um aumento gradual do I.A. e do número de T.B.R.S. nos primeiros 30-40 dias, seguido de um brusco aumento a partir de 50-80 dias mas sem alteração do pH ao longo do tempo de armazenamento. Esses resultados mostraram a ocorrência da oxidação (rancidez) da carne armazenada, mas passou despercebida pelos provadores na análise sensorial degustativa. Na análise da composição centesimal dos músculos, verificou-se que o teor de proteínas totais e de cinzas se equivalem a outras espécies de animais domésticos, sendo o teor de colágeno diferenciado à de algumas espécies. A concentração de lipídios totais mostrou-se inferior, e a concentração de colesterol é equivalente a algumas espécies de peixe. Em relação cor da carne, que foi medida em termos de concentração dos pigmentos totais existente nos músculos, os resultados encontrados mostraram ser a carne do jacaré considerada uma carne branca equivalente à carne de peixe. No estudo das formas de aproveitamento, para o consumo da carne de jacaré, fez-se uma avaliação sensorial gustativa da carne do tronco e cauda sem sofrer qualquer tipo de processamento, e os resultados foram de excelente aceitação entre os provadores. Para as medidas das características protéicas tais como: Proteínas Solúveis no Sal (P.S.S.), Capacidade de Emulsificação (C.E.), Estabilidade da Emulsão (E.E.), Capacidade de Retenção de Água (C.R.A.), que avaliam as propriedades tecnológicas necessárias no aproveitamento da carne na forma de emulsões tipo salsichas. Observou-se de uma maneira geral, que os resultados encontrados estão próximos à de outras espécies animais domésticas, encontrados na literatura, o que faz a carne do jacaré ser considerada promissora para a produção de embutidos tipo emulsão de carne. A carne salgada, considerada uma forma de aproveitamento simples e viável a nível de produtor teve um nível de aceitação razoável na análise sensorial gustativa, porém, inferior ao da carne in natura. No acompanhamento da salga, realizado através da curva de penetração de sal, perda de peso e coeficiente de difusão (D), verificou-se que entre 1-2 horas, a carne já havia absorvido 10% de sal, e perdido 10-14% de peso em 5-7 horas, com um coeficiente de difusão (D) igual a 0,42 x 10-5cm2s-l
Abstract: The aim of present study was to obtain information about the potential of Pantanal alligators Caiman crocodilus yacare (DAUDIN, 1802) to provide meat as well as to evaluate its chemical and technological characteristics to be used as a possible food source for human consumption. The quantitative aspects of the animals were assessed, taking into consideration body and carcass composition. As far as the body was concerned, the percentage of occupation was investigated on the account of four cuts from the body segment: head, trul1k, tail, and members. As for the carcass composition, leather, muscles and bones were separated during bone processing, which allowed to find out the percentage of each component in each cut. In both groups of animals, the tail showed the highest muscle yield with the relation muscle/bone varying from 7.5 to 9,5, followed by posterior limbs and trunk showing variations from 3,6 to 3,9 and 2,8 to 3,4 respectively. Variations in pH and glycogen anaerobic degradations determined changes occurred post mortem. The results indicated, in the first 20-25 hours after slaughter, the occurrence of 80%-85% of glycogen degradation and the initial pH 6.6-6.7 reached 5.5-5.7 after 35-40 hours. Meat stability during storage was evaluated by Overall Volatile Nitrogen (O.V.N.) when stored in ordinary refrigerator (5-7°C), while chemical-physical analysis were carried out during storage in freezing (-18°C). In this case, acidity level (A.L.), number of T.B.A., and pH variations were determined immediately after slaughter and during storage period. It was verified that in refrigerator storage the meat withstood during 3 or 4 days showing no signs of rejection, tasting. In freezer storage, during a period of 120-180 days, it was observed a growing but slow increase of A.L. and T.B.R.S. number in the first 30-40 days, followed by a sudden increase from 50-80 days; no pH variations occurred during the storage period. These results indicated oxidation (rancidity) which could not be noticed in the tasting analysis. In the proximate analysis of muscle centesimal composition, it was found that the content of total proteins, ashes is equal to that of other household animals, and the content of collagen lower when compared to bovine cuts. The content of total lipids was low, with the concentration of cholesterol similar to the values in some species of fish. In relation to the colour of meat measured in terms of concentration of total pigments in the muscles, the results showed that alligator meat is equivalent to fish meat. Tasting analyses were carried out in order to evaluate the yield of alligator meat by using parts of the tail and trunk without any kind of treatment and results showed a very tasteful meat. The following protein characteristics were measured: Salt Soluble Protein (S.S.P.), Emulsifying Capacity (E.C.), Emulsion Stability (E.S.), Water Retention Capacity (W.R.C.). These measure technological properties used in meat yield for emulsions of wiener. It was observed that, in general, results are very similar to those of other household species reported in literature, making the alligator meat a very favorable food source to be used in products from meat emulsion. The salted alligator meat, considered a simple and available form at the producer presented a fair level of acceptance in tasting analysis, but that level was inferior to meat in natura. During salt treatment, which was carried out using salt penetration curve, weight loss and diffusion coefficient, it was verified that between 1 and 2 hours the meat had already absorbed 10% of salt and lost 10-14% of weight in 5 to 7 hours with a diffusion coefficient equal to 0.42 x 10-5 cm2s-1
Doutorado
Doutor em Tecnologia de Alimentos
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Lundberg, Rebecca. "Persistent organic pollutants and bone tissue : studies in wild and in experimental animals /." Stockholm : Karolinska institutet, 2007. http://diss.kib.ki.se/2007/978-91-7357-410-5/.
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Molcho, Michal. "Worship and ritual in the crocodile cults of the Graeco-Roman Fayum." Thesis, University of Oxford, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.669805.
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Mazzinghy, Cristiane Lopes. "Helmintos gastrointestinais de jacarés Caiman crocodilus crocodilus Linnaeus, 1758 provenientes da Amazônia Brasileira." Universidade Federal do Tocantins, 2016. http://hdl.handle.net/11612/530.
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A criação de jacarés em cativeiro é uma forma de diminuir a caça ilegal e indiscriminada destes répteis, além de representar um negócio lucrativo devido o consumo da carne e couro no mercado internacional. Uma das espécies amplamente adotadas para a exploração em cativeiro é Caiman crocodilus crocodilus, o jacaretinga sendo as parasitoses um entrave ao bom desenvolvimento da atividade, afetando a sobrevivência e o desempenho dos animais infectados, causando interferência na produção. Sabe-se que os crocodilianos são infectados por espécies de nematodas, trematoda, pentastomídeos e acantocéfalos, todavia que poucas pesquisas são desenvolvidas com jacarés no Brasil. Assim, a identificação da fauna parasitária é importante tanto para a questão de registro, quanto para proporcionar medidas de controle em criatórios. Diante desta escassez de trabalhos acerca da identificação helmintológica em crocodilianos no Brasil e da importância destes dados na elaboração de medidas sanitárias em zoocriadouros, este trabalho visou fazer um levantamento sobre os crocodilianos bem como a cerca das espécies parasitárias já identificadas em animais no Brasil, além de conhecer os indicadores de infecções de Caiman crocodilus crocodilus procedentes da Amazônia brasileira. Seis animais foram capturados na Bacia Tocantins-Araguaia, eutanasiados e necropsiados a campo com a abertura e lavagem de cada segmento anatômico do trato digestório. Os conteúdos resultantes das lavagens foram fixados em solução de Railliet & Henry, para identificação das espécies de helmintos e determinação dos indicadores de infecção. Foram coletados 652 helmintos dos seis jacarés necropsiados, sendo observadas cinco espécies de nematodas; Brevimulticaecum baylisi, Brevimulticaecum pintoi, Brevimulticaecum stekhoveni, Dujardinascaris longispicula, Dujardinascaris paulista, Contracaecum sp., um trematoda Proterodiplostomum globulare e um Acanthocephala, com registro de um maior percentual de infecção para B. baylisi (83,3%) e uma maior abundância e intensidade média para P. globulare, com 91,5 e 274,5 respectivamente.The breeding of alligators is a way to prevent illegal and indiscriminate hunting of these species and represents a profitable business because the consumption of meat and leather in the international market. One of the species widely adopted for captive holding is Caiman crocodilus crocodilus, alligator of the Amazon. The parasitosis can be an obstacle to the good development from the activity, effecting the infected animal’s survival and the performance, causing meddling between body weight and performance and it is known that crocodilians are infected by species of nematodes, trematodes, pentastomids and Acanthocephala, so few studies are developed with alligators in Brazil. Thus, given the lack of papers about helminthological identification in crocodilians in Brazil and the importance of this datas, for both the record and for creating control measures on breeding farms, the aim of this review was to know these reptiles and specially the Caiman crocodilus yacare and the helminth fauna of crocodiles, and its importance within the species breeding and to know the helminths fauna and the infections indicators of the crocodile Caiman crocodilus crocodilus from brazilian Amazon. Six animals were captured at the Tocantins-Araguaia basin, euthanized and necropsied on the field, with the opening and cleaning of each anatomical segment of the digestive tract. The contents obtained from washes were fixed in Railliet & Henry solution, to identification of helminths species and determination of the infections indicators. In total 652 helminths were gathered, from the six crocodiles necropsied, five of them nematodes species; Brevimulticaecum baylisi, Brevimulticaecum pintoi, Brevimulticaecum stekhoveni, Dujardinascaris longispicula, Dujardinascaris paulista, Contracaecum sp., one trematoda Proterodiplostomum globulare and one Acanthocephala, with larger percentage of infection for B. baylisi (83,3%) and larger abundance and mean intensity P. globulare with 91,6 and 274,5 respectively.
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Bourquin, Sven Leon. "The population ecology of the Nile crocodile (Crocodylus niloticus) in the panhandle region of the Okavango Delta, Botswana /." Link to the online version, 2007. http://hdl.handle.net/10019/813.
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Galloway, William. "Welcome to the crocodile farm /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/6452.
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Villela, Priscilla Marqui Schmidt. "Caracterização genética de crocodilianos brasileiros e desenvolvimento de marcadores microssatélites para Paleosuchus trigonatus." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-17042009-140215/.
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A constante perda da diversidade biológica frente às pressões antrópicas tem concentrado atenções sobre a necessidade de se conhecer a diversidade genética das espécies que ainda restam como um primeiro passo para o desenvolvimento de estratégias de manejo. Técnicas de genética molecular fornecem uma estimativa do número de formas distintas numa área, bem como medidas de quão diferentes elas são. Dentre estas técnicas, o sequenciamento de DNA mitocondrial e nuclear, aliado à análise de seqüências microssatélite, geram informações potencialmente capazes de evidenciar a variação contida entre indivíduos, sendo uma ferramenta excelente para ser utilizada em análise filogenética, diferenciação interespecífica e intraespecífica. Neste trabalho utilizamos 1670pb de uma região do DNA mitocondrial incluindo o citocromo b e uma parte da região controle e 630pb do gene nuclear c-mos Para analisar a relação filogenética entre as espécies de crocodilianos brasileiros. Marcadores produzidos por PCR-RFLP baseados em seqüência do gene citocromo b no DNA mitocondrial foram desenvolvidos para a identificação molecular das seis espécies brasileiras de crocodilianos. Esta técnica além de importante na identificação das espécies poderá ser utilizada como metodologia oficial de controle da comercialização e exportação de carne e couro de jacaré. O Caiman latirostris apresenta a mais extensa distribuição geográfica entre todos os crocodilianos. No presente trabalho utilizamos marcadores microssatélites para testar a hipótese da variação genética ser relacionada com distância geográfica, em pequena e grande escala, e se a variabilidade genética das espécies esta correlacionada com diferentes sub-biomas no litoral e interior. Não foi possível a transferência de marcadores microssatélites para a espécie Paleosuchus trigonatus, sendo assim novos marcadores genéticos foram caracterizados para espécie pela construção de bibliotecas enriquecidas de DNA microssatélite.Constant loss of biological diversity due to antropic pressure has concentrated attention upon the need to know the genetic diversity of remaining species as the first step in developing management strategies. Molecular techniques provide an estimate of the number of distinct forms, as well as measurements of the extent of their differences. Among these techniques, mitochondrial and nuclear DNA sequencing along with microsatellite sequences provide information that is potentially capable of detecting any variation between individuals, which makes it an excellent tool for phylogenetic analyses, as well as inter and intraspecific differentiation. In the present work, we used a 1670bp region of mitochondrial DNA including cytochrome b and a 630bp portion of the nuclear gene c-mos to analyze the phylogenetic relationship among Brazilian crocodilian species. PCR-RFLP markers based on cytochrome b mitochondrial DNA were developed for the molecular identification of six Brazilian crocodilian species. This technique is not only important for the identification of species, but it is also useful as an official methodology for controlling commercialization and exportation of crocodilian meat and leather. Broad-snouted caimans (Caiman latirostris) geographic distribution comprises one of the widest latitudinal ranges among all crocodilians. In the present study, we used microsatellite markers to test the hypothesis that genetic variation is related to geographic distance, on a small and large scale, and if the genetic variability of a species is correlated to coastal and inland subbiomes. It was not possible to transfer microsatellite markers to Paleosuchus trigonatus, so new genetic markers were characterized for the species by constructing a microsatellite enriched DNA library.
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Wallace, Kevin. "Population dynamics and human crocodile conflict of the Nile crocodile, Crocodylus niloticus, in the lower Zambezi valley." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9226.
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The lower Zambezi valley is an important conservation area for both Zambia and Zimbabwe, encompassing areas of varying levels of habitat and wildlife protection. Crocodiles have an important role in the ecosystem a well as a significant economic value, both attributes require careful management to ensure their preservation. This study investigated depredation of crocodile nests and estimated the population with a view to parameterising models which could be used to simulate harvesting strategies. Combined with a social survey the results are discussed in terms of enlightened crocodile management. The methodology encompassed four main areas: 1) An artificial crocodile nest experiment to ascertain levels of depredation at the egg stage. 2) Crocodile population surveys to estimate the abundance and size structure. 3) Deterministic stage-based and integral projection models compare observed to predicted population structure and the influence of harvesting regimes. 4) A questionnaire survey to determine the scale of human crocodile conflict and the associated issues. The local habitat characteristics of simulated crocodile nests correlated with depredation probability and time to nest death. The crocodile population shows evidence of increasing but differed from the predicted model stage structure, indicative of a population not yet at equilibrium. Crocodile density increased in areas that had higher levels of wildlife/habitat protection. An integral projection model indicated the complex inter-relationships between population biology parameters. Perturbations affecting the smallest as well as breeding size crocodiles may cause a significant impact to lambda and fertility selection. The current human crocodile conflict mitigation is minimal and ineffective. Canoe fishing is the highest risk activity followed by collecting water. The most popular mitigation suggestions were additional water access points in villages and for selective or total removal of crocodiles. An underlying dislike of crocodiles by the local populace needs to be addressed in order for successful long-term conservation.
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Oliveira, Deyla Paula de. "Análise da paternidade de Caiman crocodilus crocodilus (L.) da reseva de desenvolvimento sustentável Piagaçu-Purus, utilizando marcadores microssatélites." Instituto Nacional de Pesquisas da Amazônia, 2010. http://localhost:8080/tede/handle/tede/2100.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Recently genetic studies have been utilized to study breeding systems of several crocodilian, however, no paternity studies involved Caiman crocodilus crocodilus. To investigate paternity, it is necessary to use highly polymorphic microsatellite loci that have high probability of exclusion of paternity and differentiating individuals. For this purpose 12 dinucleotide microsatellite loci were isolated and characterized from a genomic library enriched for the dinucleotide repetitions (CT) 8 and (GT) 8 . The 12 loci were characterized in C. c. crocodilus from the Piagaçu-Purus Sustainable Development Reserve, Amazonas, and their utility also tested in Caiman c. yacare from Cacéres, Mato Grosso. The results of the characterization indicated that these loci are adequate for the study of the breeding system and also for population studies with the Caiman crocodilus complex. Six loci with highest polymorphism, high power of paternity exclusion and with high probability of differentiating among individuals were used in a PCR multiplex system for breeding system analysis of the C. c crocodilus from the Piagaçu-Purus Sustainable Development Reserve. We genotyped 198 hatchlings from 13 nests (representing a sampling effort that varied from 30% to 100% of the hatchlings per nest) sampled in the two reproductive seasons (2007 and 2008), as well as 11 females that were beside their respective nests and 21 males, potential fathers. In 100% of the nests there was a contribution of two to four fathers, all males contributed approximately equally per clutch, and none of the genotyped males were the actual fathers of the hatchlings. No male mated with more than one female, and no female showed across-year male fidelity. All females found in proximity of nests were mothers of the hatchlings of those nests. Our study highlights that polyandry is common in this species, that no single male reproductively dominates, and that females mate with geographically distant males. Our results have important implications for conservation efforts and species management in the study area and beyond.
Nos últimos anos, estudos genéticos têm sido utilizados para investigar os sistemas de acasalamento em crocodilianos, mas até a presente data nenhuma pesquisa tinha sido realizada para investigar a paternidade de Caiman crocodilus crocodilus. Para investigar a paternidade é necessária a utilização de locos microssatélites altamente polimórficos, que apresentem uma alta probabilidade de exclusão de paternidade e permita diferenciar indivíduos. Neste sentido, foram isolados e caracterizados 12 locos microssatélites dinucleotídeos a partir de uma biblioteca genômica enriquecida com repetições de dinucleotídeos (CT) e 8 (GT) 8. Os 12 locos foram caracterizados em C. c. crocodilus da Reserva de Desenvolvimento Sustentável Piagaçu – Purus, Amazonas e também testado em Caiman c. yacare de Cáceres, Mato Grosso. Os resultados da caracterização indicaram que estes locos são adequados para o estudo do sistema de acasalamento e também para estudos populacionais com o complexo C. crocodilus. Seis locos mais polimórficos com alto poder de exclusão de paternidade e com alto poder de diferenciar indivíduos foram usados em sistema do PCR multiplex para a análise do sistema de acasalamento da espécie C. c. crocodilus da Reserva de Desenvolvimento Sustentável Piagaçu – Purus. Foram genotipados 198 filhotes de 13 ninhos (representando um esforço de amostragem que variaram de 30% a 100% de filhotes por ninho) de duas temporadas reprodutivas (2007 e 2008), além de 11 fêmeas que estavam ao lado dos respectivos ninhos e 21 machos, potencias pais. Em 100% dos ninhos houve uma contribuição de 2-4 pais, sendo que todos os machos contribuíram igualmente para a ninhada, e nenhum dos machos genotipados foram os pais reais dos filhotes. Nenhum macho acasalou com mais de uma fêmea e as fêmeas não mostraram fidelidade a um único macho. Todas as fêmeas encontradas nas proximidades dos ninhos eram as mães dos filhotes dos ninhos. Nosso estudo destaca que a poliandria é comum nesta espécie não há um único macho reprodutivo dominante e que as fêmeas copularam com machos geograficamente distantes. Nossos resultados têm implicações importantes para os esforços de conservação e manejo de espécies na área de estudo e outras áreas do entorno.
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Shacks, Vincent. "Habitat vulnerability for the Nile crocodile (Crocodylus niloticus) in the Okavango Delta, Botswana." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1651.
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Papet, Léo. "Localisation des sons chez les crocodiliens." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1337.
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Les crocodiliens ont développé des capteurs très précis pour sonder leur environnement jusqu'à atteindre leur position de super prédateur. Ces capacités sensorielles sont primordiales en situation de chasse mais elles sont également nécessaires pour assurer les interactions sociales entre partenaires sexuels ou entre parents et jeunes. Depuis l'intérieur des œufs, les embryons matures utilisent la communication acoustique pour synchroniser l'éclosion. Dans leurs premières années, les jeunes vocalisent en cas de danger pour solliciter la protection de leurs parents et assurer la cohésion du groupe afin de limiter les risques de prédation. Enfin, les vocalisations sont utilisées en parade nuptiale avant l'accouplement. Pour assurer la communication acoustique et pour chasser leurs proies depuis l'interface air-eau, les crocodiliens doivent localiser avec précision les multiples sources sonores de leur environnement. Si la perception acoustique a été un sujet d'intérêt pendant plusieurs années, les capacités de localisation sonore des crocodiliens ont été rapportées comme précises mais n'ont été étudiées que rarement. Les oiseaux, et en particulier les oiseaux vocaux, ont été testés à de nombreuses reprises pour comprendre les processus et les performances de localisation des sons, mais ces caractéristiques restent mal connues chez les espèces apparentées les plus proches : les crocodiliens. Quand ils chassent, les crocodiliens nécessitent une localisation sonore précise de leur proie. La plupart des espèces de crocodiliens sont opportunistes mais une caractéristique commune est leur méthode de chasse à l'affût ne laissant émerger que les yeux, les oreilles et les narines. Une bonne localisation est également nécessaire au cours de leur vie pour assurer leurs interactions sociales.Tout d'abord, nous avons mesuré les indices acoustiques de localisation en plaçant des microphones à l'intérieur des oreilles d'animaux juvéniles. En déplaçant une source sonore autour de l'animal, nous avons pu quantifier les signaux monauraux (fonctions de transfert relative à la tête, HRTF) et binauraux (ILD et ITD). Ensuite, nous avons entraînés des crocodiles du Nil à venir à une source sonore lorsqu'ils émettent un signal spécifique. Nous avons pu quantifier leurs performances de localisation sonore en utilisant séparément l'ILD et l'ITD. Enfin, nous avons mené des expériences de playbacks dans un environnement artificiellement bruyant. Cette dernière partie est basée sur une triple approche, en testant : des caïmans Yacare dans la nature avec des cris de détresse de jeunes individus ; des crocodiles du Nil en diffusant des appels de ses congénères ; des crocodiles du Nil entraînés dans une expérience Go/No-Go, assurant une forte motivation.Nous avons constaté que la morphologie externe de la tête des crocodiliens induit des indices acoustiques pertinents en fonction de la position de la source sonore. En mesurant les indices monauraux lorsque l'animal se reposait sur le sol et dans la position naturelle de chasse à l'interface entre l'air et l'eau - nous avons démontré que ces repères sont conservés même lorsque seulement une petite partie de la tête est émergée. Ce résultat peut suggérer une adaptation potentielle à cette position de chasse spécifique assurant des indices de localisation importants. Les crocodiles testés font preuve d'une très grande précision au cours de tâches de localisation sonore. Nos expériences ont montré que l'ITD et l'ILD sont pertinents pour estimer la position d'une source sonore et nous avons mesuré l'angle minimum audible (MAA) pour la première fois dans l'ordre des crocodiliens. Enfin, en présence d'une source de bruit dans leur environnement, les crocodiliens utilisent le démasquage spatial pour améliorer la détection de signaux acoustiques pertinentsCrocodilians developed very accurate sensors to probe their environment until raising their apex predator position. These sensory abilities are primordial in hunting situation but they are also needed to ensure social interactions between sexual partners or between parents and young. Since inside the eggs, the mature embryos use acoustic communication to synchronise the hatch. In their first years, juveniles use to call in case of danger for the help of their parents and ensure the cohesion of the group to limit the predation risks. Finally, acoustic vocalisations are used in courtship before mating. To ensure acoustic communication and to hunt their preys from the air-water interface, crocodilians need to precisely localise the multiple sound sources from their environment.If the acoustic perception was a subject of interest for several years, crocodilians’ sound localisation abilities were noted to be accurate but were studied only a few times. One situation in which crocodilians need to precisely locate a sound source is when they are hunting. Sound localisation is also necessary during their first years when they are subject to predation. When they feel in danger, young crocodilians use distress calls which are relevant to signal their position to their parents when eliciting a protection behaviour from them. Finally, sound localisation may be used to find a partner in the wild when we know that some species are capable of long journeys.To explore sound localisation in crocodilians, we quantified their sound localisation abilities and observed observe how they are able to deal within a noisy environment. First, we measured sound localisation cues by placing microphones inside the ears of juvenile animals. By moving a sound source around the animal, we were able to quantify monaural (Head-Related Transfer Functions, HRTF) and binaural cues (Interaural Level and Time Differences, ILD and ITD). Then, we trained Nile crocodiles to come to a sound source when playing a specific signal. By filtering these signals before playing them to the animal, we were able to quantify their sound localisation performances when using separately ILD and ITD. Finally, we conducted some playbacks experiments in an artificially noisy environment. This last part was constituted by a triple approach, by testing: Yacare caimans in the wild with distress calls of hatchlings; Nile crocodiles hatchlings by simulating a separation from the group and broadcasting calls from its congeners; trained Nile crocodiles in a Go/No-Go experiment, ensuring a high motivation.We evidenced that the external morphology of the crocodilians head induces potentially relevant external acoustic cues depending on the position of the sound source. By measuring the monaural cues in two situation -when the animal was resting on the ground and in the natural hunt position at the interface between air and water- we demonstrated that those cues are conserved even when only a small part of the head is emerged. This result may suggest a potential adaptation to this specific hunting position ensuring strong localisation cues. The tested crocodiles evidence very precise abilities in sound localisation tasks. Our experiments showed that both ITD and ILD are relevant when estimating the position of a sound source and we measured the Minimum Audible Angle (MAA) for the first time in the crocodilians order. Finally, in a presence of a noise source in their environment, crocodilians perform Spatial Release from Masking to increase the detection of relevant acoustic signals
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Kontuľová, Dominika. "Ocenenie spoločnosti Crocodille ČR, spol. s.r.o." Master's thesis, Vysoká škola ekonomická v Praze, 2017. http://www.nusl.cz/ntk/nusl-358949.
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The aim of this master's thesis is to estimate objectified value of the company Crocodille ČR, spol. s.r.o. for the needs of management and owners by the date 31st of December 2015 for the purposes of identifying value-creation factors from the point of view of the competitiveness of the company. The thesis is divided into two main parts. The theoretical part describes the key concepts related to the valuation of company as well as process of valuation. The practical part contains a introduction of the company, strategical analysis, analysis and prognosis of value drivers, financial plan and finally valuation of the company based on revenue methods FCFF and EVA.
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Pelouin, Annick. "Analyse du film "pour enfants" : katia et le crocodile." Paris 1, 1988. http://www.theses.fr/1988PA010531.
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Les grandes etapes de l'analyse du film : katia et le crocodile - j'ai commence a justifier le choix pour ce film, qui est du : a son grand succes aupres des enfants, et parcequ'il est considere comme un modele de film pour enfants, par les instances educatives les critiques, les organismes diffusant ou faisant la promotion du cinema pour enfants. - j'ai montre comment les spectateurs enfants, le percevaient (d'apres des interviews recueillis pendant et apres la projection du film. - j'ai fait une analyse sur la construction du film, pour voir si ce- lui-ci etait adapte aux possibilites physiologiques et pshychologiques des enfants, tels que le supposaient les critiques. - j'ai degage les intentions conscientes du film, qui etaient de distraire et de faire rever (d'apres l'auteur) en essayant d'en mesurer l'impact; - j'ai montre que derriere les intentions conscientes du film se cachaient des intentions inconscientes (que devoilaient aussi les commentaires des enfants). - aussi le point de vue des enfants, l'analyse sur la construction du film et sur son contenu, montrent que ce film ne correspond pas dans l'ensemble aux criteres evoques sur les "bons films pour enfants". . .
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Pelouin, Annick. "Analyse du film "pour enfants" "Katia et le crocodile /." Lille 3 : ANRT, 1989. http://catalogue.bnf.fr/ark:/12148/cb37617471w.
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Jaratlerdsiri, Weerachai. "Characterisation, diversity and evolution of the saltwater crocodile MHC." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/11659.
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Abstract The saltwater crocodile (Crocodylus porosus) forms the basis of a crocodile farming industry for the international skin trade in Australia. For this industry, mortalities from stress and disease are common due to a compromise of the adaptive immunity. Currently the genetic understanding of the immune response is poor, which in turn impedes an understanding of genes, and hence genetic markers, affecting disease susceptibility. As a key component of adaptive immunity is the Major Histocompatibility Complex (MHC), this thesis characterises the MHC genes with an emphasis on the saltwater crocodile and assesses genetic diversity, evolutionary mechanisms that are influencing diversity and their roles in adaptive immunity. The genetic diversity among saltwater crocodiles showed the number of MHC variants within an individual ranging from one to seven, indicating that there are at least four gene loci in this species. An association between a certain MHC variant and Lymphoid proliferation/ Vasculitis/ Encephalitis in saltwater crocodiles was identified (P = 0.00007), suggesting genetic susceptibility to the disease. Phylogenetic analyses showed that MHC variants from 20 species of Crocodylia clustered at the genus or family level rather than in species-specific groups, indicating orthologous relationships. Selection detection analyses showed that balancing selection influenced some classes of MHC in Crocodylia. In addition, construction of Bacterial Artificial Chromosome scaffolds in the saltwater crocodile showed MHC class I genes located along with antigen processing genes and a framework gene. This would support structural variation of the saltwater crocodile MHC that differs from that expected in tetrapod ancestors. This project offers a better understanding of immunogenetics and immunogenomics in Crocodylia and presents recommendations for future research, where these findings could serve as a foundation in order to achieve a complete picture of MHC in Crocodylia.
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Marconato, Leonardo De Palma. "Dois novos crocodilos (Crocodyliformes, Mesoeucrocodylia) do Mato Grosso, Bacia dos Parecis : descrição e relações filogenéticas com os "Notossúquios"." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/7769.
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São descritos dois novos táxons de Crocodyliformes do Cretáceo do Mato Grosso, que apresentam: crânios curtos; dentição heterodonte composta por dentes com lado labial mais convexo que o lado lingual e serrilhados; dentes anteriores do dentário procumbentes; presença de uma superfície distintamente lisa, acima da margem alveolar, na superfície lateral da maxila, acima da qual ocorrem forames neurovasculares; e vértebras anficélicas. Estes novos materiais foram informalmente chamados Crocodilo I e Crocodilo II. O Crocodilo I apresenta as seguintes características: fenestra pré-orbitária pequena; barra palatina posterolateral em forma de bastão; dente caniniforme hipertrofiado na pré-maxila; 6 dentes maxilares; dentes anteriores do dentário levemente voltados para trás; junta quadrado-articular localizada ventralmente à fileira dentária. O Crocodilo II, por sua vez, apresenta: focinho tubular em seção; amplo palato secundário; espleniais fusionados; 5 dentes maxilares; mandíbula com região sinfiseal alongada e espatulada. Em ambos os casos, a morfologia geral aponta muitas semelhanças com os “notossúquios”: postura elevada, regiões diferenciadas na coluna, dentição heterodonte, palato secundário relativamente amplo e cavidade nasal relativamente ampla. Para testar as relações filogenéticas dos dois táxons, bem como o próprio monofiletismo dos “notossúquios”, foi construída uma matriz de dados com 27 táxons (incluindo, tanto quanto possível, todos aqueles que já foram ou são considerados “notossúquios”) e 60 caracteres. Com base nos mesmos, foi efetuada uma análise de parcimônia utilizando Paup 3.1.1 (“stepwise addition” - “random”, com 100 repetições e “tree-bisection-reconnection”) e Nona 2.0 (algoritmo heurístico, com 10 replicações e TBR - mult*max*) que apontou uma relação dos dois novos táxons como grupos irmão sucessivos de Notosuchus e Mariliasuchus (Crocodilo II (Crocodilo I (Notosuchus, Mariliasuchus))). Em comparação com outros crocodiliformes do Cretáceo da América do Sul, África, Madagascar e China, é possível assumir que ambos são notossúquios (sensu Pol & Apesteguia, 2005). Em nossa análise, os notossúquios formam um grupo, à exceção de A. buitreraensis, mais proximamente relacionado aos Eusuchia. Na análise ordenada, A. buitreraensis, A. patagonicus e Anatosuchus aparecem mais proximamente relacionados a Eusuchia e Lybicosuchus aloca-se junto a Baurusuchus e Sebecus. Paralelamente, são discutidas análises filogenéticas prévias envolvendo notossúquios, nas quais foram introduzidas modificações, levando a diferentes topologias. A partir disso, propõe-se uma discussão acerca da influência das escolhas e procedimentos de cada autor no resultado final de análises filogenéticas.
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Nóbrega, José António Lemos Barão. "O custo da nidificação em Caiman crocodilus na Amazónia Central." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12030.
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Mestrado em Biologia Aplicada - Ecologia, Biodiversidade e Gestão de EcossistemasDurante a seca sazonal (outubro-dezembro) de 2012, estudamos alguns aspetos relacionados com a nidificação de Caiman crocodilus na Reserva de Desenvolvimento Sustentável Piagaçu-Purus. Neste estudo descrevemos a dieta, condição corporal e alguns parâmetros sanguíneos das fêmeas nidificantes, fêmeas não nidificantes e machos adultos de C. crocodilus. Avaliamos também a relação entre o índice de condição corporal de Fulton “K” e os parâmetros sanguíneos analisados, avaliamos o efeito da idade do ninho e sua localização no interior da floresta na condição corporal e parâmetros sanguíneos das respetivas fêmeas e fizemos uma comparação com Melanosuchus niger para tentar avaliar se os resultados obtidos neste estudo, refletem a biologia reprodutiva da espécie. Na Piagaçu-Purus, o cuidado parental pareceu influenciar a dieta das fêmeas nidificantes de C. crocodilus, uma vez que a proporção de estômagos vazios foi significativamente superior em fêmeas nidificantes, a ocorrência de alimento fresco em fêmeas nidificantes foi significativamente inferior ao observado em fêmeas não nidificantes e a composição da dieta foi significativamente diferente entre os dois grupos de fêmeas. Verificamos que os valores de condição corporal e níveis plasmáticos de glicose, triglicerídeos e lactato das fêmeas nidificantes foram significativamente inferiores aos valores observados em fêmeas não nidificantes e machos. Por outro lado, os valores plasmáticos de ácido úrico das fêmeas nidificantes foram significativamente superiores aos observados em fêmeas não nidificantes e machos. Apenas encontramos relação entre o índice de condição corporal e os níveis de triglicerídeos em fêmeas nidificantes. O nosso estudo demonstrou que a idade do ninho (i.e. o tempo em que a fêmea ovopositou) e sua localização no interior da floresta representam fatores de influência negativa na condição corporal da respetiva fêmea. Isto significa que, de maneira geral, fêmeas que construíram o ninho há mais tempo ou em distâncias maiores no interior da floresta tendem a apresentam uma condição corporal mais fraca. Além disso, parece haver relação positiva entre os níveis de glicose e a sua localização no interior da floresta. A idade do ninho demonstrou estar negativamente correlacionada com níveis de triglicerídeos, lactato e ácido úrico. Os resultados obtidos em C. crocodilus, quando comparados com M. niger, parecem refletir a própria biologia da espécie. Assim sendo, a estratégia de nidificação de C. crocodilus demonstrou ter um custo metabólico associado ao sucesso de eclosão dos ovos, que parece ser dependente das reservas de energia da fêmea.
During the dry season (October-December) of 2012 we studied some aspects related to nesting ecology of Caiman crocodilus in Piagaçu-Purus Self Development Reserve. In this study, we described the diet, body condition and some blood parameters of C. crocodilus nesting females, non-nesting females and adult males. We also evaluated the relation between Fulton’s “K” body condition index and the blood parameters determined, evaluated the effect of nest age and nest location inside de forest on body condition and blood parameters of nesting females and made a comparison with Melanosuchus niger in order to evaluate if the results of our study reflect the breeding biology of the species. In Piagaçu-Purus, nest attendance seemed to influence the diet of C. crocodilus because the proportion of empty stomachs was significantly superior in nesting females and the occurrence of fresh food items was significantly inferior, when compared to non-nesting females. Also, dietary composition was significantly different between the two female groups (nesting and nonnesting). Body condition and blood levels of glucose, triglycerides, and lactate of nesting females were significantly lower, when compared to non-nesting females and adult males. On the other hand, blood levels of uric acid were higher in nesting females. We only found relation between Fulton’s “K” body condition index and the blood levels of triglycerides in nesting females. Our study demonstrated that nest age and nest location inside the forest have a negative effect on female body condition. This means that, in a general way, females attending older nests or nests built further away inside the forest tend to have lower body condition values. Thus, there seems to be a positive relation between blood levels of glucose and nest location inside the forest. Nest age was negatively correlated with blood levels of triglycerides, lactate and uric acid. The results obtained for C. crocodilus, when compared to M. niger, seem to reflect the very own biology of the species. Thereby, the nesting strategy of C. crocodilus demonstrated to have a metabolic cost associated to hatching success and seems to be dependent of female energy reserves.
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Hua, Stéphane. "Adaptations des crocodiliens mesosuchiens au milieu marin." Paris 6, 1997. http://www.theses.fr/1997PA066101.
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Quatre familles de crocodiliens mesosuchiens mesozoiques sont connues pour s'etre adaptees au milieu marin. Il s'agit par ordre d'apparition stratigraphique des teleosauridae geoffroy, 1831, des metriorhynchidae fitzinger, 1843, des pholidosauridae eastman, 1902 et des dyrosauridae de stefano, 1903. Le but de ce memoire etant de mieux cerner la paleoecologie et la paleophysiologie de ces organismes fossiles, il est fait un rappel de quelques elements d'hydrodynamique et de locomotion qui serviront de base au raisonnement utilise. Ces mesosuchiens fossiles beneficient de relativement bons equivalents actuels, notamment crocodylus porosus, le crocodile indo-pacifique. A ce titre, la biologie et l'ethologie des crocodiliens actuels a affinites marines sont abordees. De cette base actualiste, les tendances evolutives des thalattosuchiens (teleosauridae + metriorhynchidae), des pholidosauridae et des dyrosauridae sont detaillees et comparees aux reptiles marins contemporains. Une nouvelle methode permettant de decrire les mouvements vertebraux relatifs a chaque region, est proposee : les profils de locomotion. Les conclusions morphofonctionnelles ainsi obtenues sont confrontees a une analyse histologique inedite chez certains groupes. L'histologie revele qu'en depit de profondes modifications morphologiques, notamment chez les metriorhynchidae, les mesosuchiens marins n'ont jamais developpe de processus endothermique. Ceci implique un role de predateurs chassant plutot en embuscade ne pouvant pratiquer de nage soutenue sur de longues distances. Enfin, une analyse des paleoenvironnements de chacune des quatre familles de crocodiliens marins est effectuee. En conclusion, le bilan des donnees acquises retracant l'histoire ou plutot les histoires de ces quatre familles de reptiles marins est fait. Il est montre que les conclusions qui s'y rapportent ne sont pas sans incidence sur notre connaissance de la biogeographie des crocodiliens actuels.
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Wright, Jonathan C. (Jonathan Caldwell). "Diving and exercise physiology in the estuarine crocodile, Crocodylus porosus." Thesis, The University of Sydney, 1985. https://hdl.handle.net/2123/26901.
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Metabolic and respiratory physiology of juvenile Estuarine Crocodiles, Crocodylus porosus, were examined under the following conditions: rest on land, voluntary submergence and exhaustive activity on land.
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Chong, Amanda Yoon-Yee. "Characterisation of endogenous retroviruses in the saltwater crocodile (Crocodylus porosus)." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10418.
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Amanda CHONG Characterisation of endogenous retroviruses in the saltwater crocodile (Crocodylus porosus) Endogenous retroviruses (ERVs) are a diverse group of vertebrate transposable elements, and are derived from germline infections by exogenous retroviruses. Very few studies have been carried out investigating the diversity of ERVs in non-mammalian vertebrates despite evidence that these species harbour a diverse and divergent ERV complement. This project constitutes the first comprehensive investigation of endogenous retroviruses (ERVs) in crocodilians. The research presented herein encompasses the characterisation of crocodilian ERVs from key crocodilian species, and explores the evolutionary dynamics of these ERVs within their host genomes. It also offers insights into the evolution of ERVs and exogenous retroviruses. Overall, this project has demonstrated that crocodilians, and likely other non-mammalian vertebrates, are a rich source of novel ERV diversity, and may provide unique insights into the evolution of modern exogenous retroviruses and their hosts. It has also highlighted the relative merits of a wide variety of ERV detection techniques, both molecular and bioinformatic, and how these may be adapted for studies of previously uncharacterised taxa. This project will provide a useful resource to facilitate further investigations into the significance of ERVs in crocodilian biology, and offers insights into how these approaches may be translated to studies of other vertebrate taxa.
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Brittain, Katherine Patricia. "Genetic and genomic diversity of crocodylians: applications in evolution and immunogenetics." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29800.
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There are ~27 recognised extant species of crocodylians (Crocodylia), which inhabit a large range of tropical, fresh- or saltwater ecosystems around the world. Crocodylians appear to have an effective immune system that allows them to cope with a variety of pathogenic challenges. Crocodylians have been shown to live with a range of opportunistic infections, and yet wild animals seldom display disease symptoms. Also, reptile immune systems are less well studied than their mammalian and avian counterparts, and yet reptiles hold a unique evolutionary position as cold-blooded amniotes. Studying the evolutionary rates and diversity of immune system components in crocodylians could contribute to our overall understanding of the development of the immune system. Genetic and peptidome studies of the crocodylian immune system have improved our understanding of the organisation, evolution and diversity of some components of the adaptive immune system, however, there is much yet undiscovered when it comes to components that modulate the functions of the adaptive and innate immune systems in crocodylians. The availability of genomic resources would be beneficial to further investigations into disease susceptibility and resistance in industry and endangered wild populations. At present, only four crocodylian draft genomes have been sequenced and are publicly available. The projects undertaken in this thesis were initiated due to the limited genomic and immunogenetic resources available for crocodylian species. This research was to provide foundations in a key immune modulatory system in crocodylians, as well as to investigate applications of crocodylian genomic data in answering current evolutionary and immunogenetic questions.
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Hester, Dean Armstrong. "A review of the Paleogene eusuchian crocodyliform Borealosuchus wilsoni (Mook, 1959) from western North America." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6131.
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Borealosuchus Brochu 1997 was erected for a group of Late Cretaceous through early Eocene eusuchian crocodyliform species formerly assigned to Leidyosuchus Lambe 1907. Borealosuchus wilsoni was originally described by Mook (1959) based solely on a dorsoventrally crushed skull from the early Eocene (Wasatchian) Green River Formation of Wyoming, and assigned to Leidyosuchus. Later analyses referred specimens from the late Paleocene and middle Miocene to the species (Brochu, 1997). In phylogenetic analyses, Borealosuchus has been retrieved as either a basal crocodylian (e.g., Salisbury and Willis, 1996; Brochu, 1997; Wu et al., 2001; Buscalioni et al., 2011; Brochu et al., 2012; Narváez et al., 2016) or a close crocodylian outgroup (e.g. Benton and Clark, 1988; Pol et al., 2009; Turner and Pritchard, 2015). More exact phylogenetic placement of Borealosuchus remains unclear. Borealosuchus wilsoni is stratigraphically the youngest species of Borealosuchus, and one of the most completely known, and as such, it figures prominently in ongoing debates over the phylogenetic relationships and origin of crown group Crocodylia. Given its long stratigraphic range in the literature, the question of whether specimens currently referred to B. wilsoni all pertain to a single species is open.
This study focuses on a more thorough description of the skeletal morphology of Eocene Borealosuchus, and a revision of the taxonomy of this assemblage, including the conspecific nature of Wasatchian Borealosuchus wilsoni and middle Eocene (Bridgerian) fossils referred to Borealosuchus wilsoni, including material of Diplocynodon stuckeri Mook 1960. A phylogenetic re-assessment of B. wilsoni will hopefully provide further resolution within Borealosuchus and among other closely related taxa.
Specimens were coded with a matrix of 190 morphological characters and subjected to phylogenetic analysis. The diversity of Borealosuchus during the Eocene has been underestimated and specimens from the Bridgerian are diagnosable and distinct from those of the preceding Wasatchian stage. A new species will be erected to contain this material. The erection of a new species of Eocene Borealosuchus renders the holotype of D. stuckeri non-diagnostic at the species level, and a new holotype USNM 12990 is designated for Bridgerian Borealosuchus. Some specimens assigned to Brachyuranochampsa eversolei and Crocodylus affinis may also be referable to Borealosuchus. The addition of new material to Borealosuchus increases the diversity of this group during the Eocene.
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White, S. C. "In the teeth of the crocodile : Class and gender in rural Bangladesh." Thesis, University of Bath, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380024.
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Bekker, Lasya Christina. "Nile crocodile (Crocodylus niloticus) urine as sample for biochemical and hormonal analyses." Thesis, University of Pretoria, 2016. http://hdl.handle.net/2263/60124.
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Urine samples are routinely used in human and animal patients to diagnose health problems; often to investigate or monitor specific health-related problems that essentially may remain silent for extended periods. However, not much work has been performed on crocodilian urine for diagnostics. In general, crocodilian species lack a bladder as a separate storage organ (as found in mammals), possess metanephric kidneys (unable to concentrate urine) and have functional salt excreting glands. Collection of urine from the Nile crocodile (Crocodylus niloticus) is a simple and atraumatic procedure where a dog urinary catheter is used to collect relatively clean urine from the urinary chamber in the crocodile’s cloaca. Unfortunately, in-depth investigations of urine variables, and establishing baseline concentrations, have not been performed on Nile crocodile urine samples before. The specific focus areas of this research project were: (1) determination of urine and plasma biochemical concentrations by means of a standard veterinary clinical pathology profile and the establishment of the ratio between urine and blood biochemical parameters; (2) the validation of a gas chromatographic–mass spectrometric (GC/MS) method for the determination of steroid metabolite concentrations in urine; and (3) using this established analytical method to determine the presence (identify) and concentrations of steroid metabolites in the urine of individual crocodilians.Urine and plasma samples collected at Izintaba Crocodile Farm during the period November 2005 to July 2006, from captive bred, healthy young Nile crocodiles, were analysed for standard biochemistry variables. The urine samples (n = 101) were analysed for sodium, potassium, chloride, urea, creatinine, calcium, magnesium, phosphate, uric acid, osmolality, and ammonium ion, while the plasma samples (n = 101) were screened for total protein, glucose, sodium, potassium, chloride, urea, creatinine, total calcium, ionised calcium, magnesium, phosphate, uric acid and osmolality. Means, medians and standard deviations were statistically determined, as well as urine to plasma (U/P) ratios for corresponding variables. The value of this project is the establishment of reference concentrations for Nile crocodile urine samples that may become useful for interpretation of laboratory results, in future.
The clinical validation of a GC/MS method for the analysis of urinary steroids in the Nile crocodile was achieved using urine samples from two-year-old Nile crocodiles. The main objective of this investigation was to develop, optimize and validate the laboratory analysis of urinary steroid metabolites. Steroid profiling was performed on individual and pooled Nile crocodile urine samples. Ascending concentrations of representative steroid standards: androsterone, etiocholanolone, dehydroepiandrosterone, 11-OH androsterone, pregnanediol, pregnanetriol, 11-deoxytetrahydrocortisol, tetrahydrocortisone, tetrahydrocortisol and tetra-hydrocorticosterone, were spiked into aliquots of the pooled urine samples, to obtain calibration samples ranging from 0.2 to 20 μg. Sample preparation and analysis methodology were based on a well-established, validated GC/MS method for determination of human urinary steroid metabolites. The validation of the GC/MS method for Nile crocodile urine was successfully completed, by determining lower limits of quantitation and limits of detection for each analyte, obtaining linearity up to the highest calibration level, correlations exceeding 0.90, and recoveries of 82% and more.
Steroid profiling was performed on urine samples collected from a number of mature crocodilian species, namely Nile crocodile, American alligator (Alligator mississippiensis), spectacled caiman (Caiman crocodilus) and dwarf crocodile (Osteolaemus tetraspis). Steroid metabolites were identified and were quantitated and reported per urinary creatinine. Qualitative reporting was conducted in cases where creatinine concentrations were not available. Results included identification and quantitation of the steroid metabolites: androsterone, etiocholanolone, 11-hydroxy androsterone, pregnanediol, pregnanetriol, and the tetrahydro- metabolites of cortisone (THE), cortisol (THF), and corticosterone (THB). In some urinary steroid profiles, several prominent peaks were observed which could not be identified. The study findings confirmed that crocodile urine could successfully be used, as it is commonly used in humans, to determine steroid metabolite profiles. A follow-up study to identify the unknown peaks by structure elucidation with more sophisticated equipment is recommended - this could lead to valuable information about liver metabolism of steroids in crocodilians.
An adrenocorticotrophic hormone (ACTH) stimulation test was conducted on 18 captive Nile crocodiles. The experimental animals were temporarily housed in separate enclosures at Le Croc Crocodile Farm for four weeks, to ensure controlled conditions and easy and frequent access to the animals. Twenty-seven urine samples were collected both pre- and post-ACTH or saline injections. Steroid profiling was performed on 24 of the 27 urine samples to assess the corticosterone and tetrahydrocorticosterone concentrations following the ACTH treatment. Quantitation relative to urine creatinine levels was recorded following analyses with a standardised liquid chromatography/mass spectrometry (LC/MS) method, reporting the concentrations in nmol steroid/μmol creatinine. Unfortunately, a significant increase in urinary corticosterone concentrations 6 h after the injection of Synacthen® (5 μg/kg) was not observed. A possible explanation for this could be that the 6 h period was too short for a significant increase in urinary glucocorticoid metabolite excretion in the Nile crocodile.
In conclusion, this is the first in-depth study that focused, specifically, on Nile crocodile urine for analyses as diagnostic tools and for indices of health. The screening of the urine samples, collected from healthy Nile crocodiles, for a large array of biochemical variables contributed significantly to the database of “normal” concentrations. The establishment of a validated urinary steroid profiling method may significantly contribute to future validation and implementation of innovative diagnostic methods to monitor the health status and endocrine systems of wild Nile crocodiles in Africa.
Thesis (PhD)--University of Pretoria, 2017.
The Norwegian Council for Higher Education’s Programme for Development, Research and Education (NUFU)
Royal Netherlands Embassy in South Africa
Crocodile Specialist Group
SAVF
Paraclinical Sciences
PhD
Unrestricted
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Riep, David Matthew Merkel. "House of the Crocodile: south Sotho art and history in southern Africa." Diss., University of Iowa, 2011. https://ir.uiowa.edu/etd/2616.
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The inability to attribute art objects to the Basotho culture remains a problem for art historians and anthropologists alike. Current publications on the arts of Africa include few, if any, objects attributed to South Sotho-speakers, and often attribute Basotho objects under the broad label of "southern African," rather than linking them to artists from this particular culture. This is largely due to a lack of research on Basotho arts and culture, as well as the widespread belief that the cultures of the region are simply too enmeshed with one another for the arts to be distinguished. However, it is important that we be able to tell the art of one African people from another if we are ever to understand accurately how art expresses peoples' ideas and beliefs about themselves and the world in which they live. Through this project I challenge the label of "southern Africa" that is so often used in attributing art objects from the region, and develop a definitive system of identification for Basotho objects. This system differentiates Basotho arts from works produced by other cultures in southern Africa, and produces the first all-inclusive anthology of South Sotho art history. While my work first and foremost demonstrates the existence of a unique and identifiable Basotho visual style, it also investigates the roles that stylistic characteristics have played in the presentation of southern Sotho identity beginning with the formation of the Basotho polity 200 years ago. Furthermore I identify the contextual and cultural significance of an entire range of Basotho forms, generating a better understanding of Basotho art and culture.
In order to complete this, I use a Morellian approach to identify and define the unique and specific visual aspects found among Basotho arts. This type of analysis is based solely on the external physical characteristics of a work of art, and focuses on the identification of similarities and differences within a group of objects. The resulting data provides a taxonomy for the classification of cultural, regional, and local styles through the isolation of the visual aspects of individual objects. However, because the Morellian methodology takes a morphological approach, I use historical literature and contemporary interviews to connect the function and social context to the objects in order truly to develop an art history of the Basotho. Through this analysis, I identify visual aspects that are unique to southern Sotho arts, and further locate visual signs that assert one's specific clan lineage within the broad "southern Sotho" cultural grouping. This allows me to clearly define the meaning and significance of the "Basotho" cultural moniker, and develop a nuanced understanding of identity amongst southern Sotho peoples.
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Carvalho, Thiago dos Santos. "MANEJO E USO SUSTENTÁVEL DO JACARETINGA (Caiman crocodilus) POR RIBEIRINHOS: UM ESTUDO AVALIATIVO." Pontifícia Universidade Católica de Goiás, 2011. http://localhost:8080/tede/handle/tede/3133.
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Previous issue date: 2011-12-09The Brazil finds itself in a privileged position to promote the use of wild life as a mechanism for conservation and sustainable development. Throughout the project study area populations of Caiman crocodilus were observed in the middle of the Araguaia river basin, and in the lower Madeira River in RESEX Cuniã thereby assessing the conservation status and structure of existing populations of alligators there. The data on the populations of Caiman crocodilus may support studies aimed at the sustainability of this species. The present work has as main objective the conservation tinga alligator (Caiman crocodilus) with the availability of information to ex situ management production programs and human settlements around the protected areas, reducing hunting pressure. The study areas were selected owing to their location close to environmental protection areas, and have inside human communities that have always used alligators as a food source and so where there is a need to work to create sustainable technologies of breeding and laughter of alligators providing new sources of income for the community, reducing human pressure on this species. Were conducted throughout the study for the two protected areas, eight field campaigns in the years 2007 to 2009. Sampling field trips were conducted in March, April, August, September, October, and November to allow a comparison of the distribution patterns over the years and observe what environmental factors are influencing the distribution patterns of species Caiman crocodilus. 1,549 individuals of Caiman crocodilus were spotted throughout the study in the APA Meandros do Araguaia during the years 2007 and 2008 with the presence of all size classes (I,II,III and IV). In the RESEX Cuniã 476 Caiman crocodilus individuals were spotted during the years 2008 and 2009. Environmental education was directed towards the capacitating of local communities that agreed to participate in the work through training, lectures and technical visits in order to keep the community involvement in the work. The exploration of the meat and skin could be must occur on an experimental basis and accompanied very closely by research. The two areas where this work was carried out have a great potential for some sustainable management, as they to possess in their interior large populations of tinga alligator with all size classes. The results of this study are preliminary and require further complementation.
O Brasil encontra-se numa posição privilegiada para promover o uso da vida silvestre como mecanismo de conservação e desenvolvimento sustentado. Na área de estudo ao longo de todo o projeto foram observadas as populações de Caiman crocodilus no médio da bacia do rio Araguaia, e na região do baixo Madeira na RESEX Lago do Cuniã com isso avaliando o status de conservação e estrutura das populações de jacarés lá existentes. Os dados sobre as populações de Caiman crocodilus poderão subsidiar estudos visando à sustentabilidade desta espécie. O presente trabalho tem como principal objetivo a conservação do jacaretinga (Caiman crocodilus) com a disponibilização das informações para programas de manejo em produção ex situ por ribeirinhos e comunitários do entorno de Unidades de Conservação, diminuindo a pressão de caça. As áreas de estudo, foram selecionadas por se tratar de locais de proteção ambiental (Unidades de Conservação), e possuírem em seu interior comunidades ribeirinhas que sempre utilizaram os jacarés como fonte de alimento e assim onde há a necessidade de se trabalhar tecnologias sustentáveis para a criação e abate de jacarés proporcionando novas alternativas de renda para os comunitários, diminuindo a pressão antrópica sobre esta espécie. Foram realizadas ao longo do estudo para as duas Unidades de Conservação, 8 campanhas de campo nos anos de 2007 a 2009. As amostragens foram realizadas nos meses de março, abril, agosto, setembro, outubro e novembro de forma a permitir uma comparação nos padrões de distribuição no decorrer dos anos e verificar quais fatores ambientais estão influenciando nos padrões de distribuição da espécie Caiman crocodilus. Foram visualizados 1.549 indivíduos Caiman crocodilus ao longo de todo o estudo na APA Meandros do Araguaia durante os anos de 2007 e 2008 com a presença de todas as classes de tamanho (I, II, III, e IV). Já na RESEX Cuniã Foram visualizados 476 indivíduos Caiman crocodilus durante os anos de 2008 e 2009. A educação ambiental foi direcionada para a capacitação dos comunitários e ribeirinhos que se disponibilizaram a participar do trabalho por meio de treinamentos, palestras e visitas técnicas no intuito de manter o envolvimento da comunidade no trabalho. A exploração da carne e pele poderá ocorrer de forma experimental e acompanhada muito de perto pela pesquisa. As duas áreas onde foi feito o presente trabalho têm um grande potencial para algum manejo sustentável por possuírem em seu interior grandes populações de jacaretinga de todas as classes de tamanho. Os resultados do presente estudo são preliminares e requerem complementações.