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Jones, A. E. "Stage-structured insect population models of larval competition." Thesis, University of Strathclyde, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381490.
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Cole, Alison G. "Cell-lineage of the larval CNS in the ascidian Ciona intestinalis, neurula stage through to hatched larva." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ57277.pdf.
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Saunders, Laura Margaret. "Infection strategies of gamebird macroparasites." Thesis, University of Stirling, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341230.
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Matzilevich, David Avicenna. "Molecular analysis of superoxide dismutase and other antioxidant enzymes of Toxocara canis." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266226.
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Lewis, Solange Smita. "Identification of stress-responsive genes in the early larval stage of the fathead minnow pimephales promelas." Cincinnati, Ohio : University of Cincinnati, 2005. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1134665105.
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Thesis (Ph. D.)--University of Cincinnati, 2005.Advisor: Stephen Jay Keller. Title from electronic thesis title page (viewed Apr. 22, 2009). Keywords: fathead minnow; differential display; larvae; real-time PCR; copper; zinc; thermal stress; stress; gene expression. Includes abstract. Includes bibliographical references.
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Stanley, Jenni Anne. "Ambient underwater sound: measuring the importance of spatial viariability and its effect on late stage larval crabs." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/6975.
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Recent studies have shown that underwater sound emanating from coastal reefs may be used for guiding the movements of a wide range of reef organisms to suitable settlement habitats. However, it is not known whether this underwater sound is also capable of mediating the settlement and metamorphosis processes in these organisms. The present study used laboratory- and field-based methods to determine whether ambient underwater sound is used as a settlement and metamorphosis cue in 10 species of larval crabs. The settlement stage larvae of five common crab species showed marked changes in swimming behaviour consistent with settlement and showed a significant decrease in time to metamorphosis (TTM) when exposed to replayed ambient reef sound compared with a silent control. Ambient underwater sound has the potential to convey valuable information about the type and suitability of the habitat at its source to settlement stage pelagic larvae provided different habitats produce distinctive underwater sound. Analyses of recordings from several different habitat types along the coast of north-eastern New Zealand showed that the sound emanating from different habitat types had marked differences in terms of gross character, i.e., spectral composition and sound level. When habitat specific sounds were used in laboratory- and field-based experiments a significant decrease in TTM was observed for settlement stage crab larvae exposed to favourable settlement habitat sound when compared to unfavourable habitats. Behavioural thresholds for habitat sound were determined experimentally by exposing settlement stage larvae to a range of sound levels from both favourable and unfavourable habitat types for settlement. Larvae did not respond to sound from unfavourable habitat types. However, for sound from favourable habitat types for settlement most crab species showed increasing reductions in TTM as sound levels were increased, suggesting that proximity to the sound source or settlement habitat is important in inducing faster settlement. The results presented in this thesis demonstrate that ambient underwater sound originating from coastal habitats mediates the settlement processes of the megalopae of many common coastal crab species in both temperate and tropical waters. It provides evidence that differences in the spatial and biological characteristics of underwater sound play a significant role in this process. Overall, the results of this research greatly extend our knowledge of the importance of underwater sound to recruitment processes of coastal larvae.Whole document restricted until August 2012, but available by request, use the feedback form to request access.
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Lewis, Solange Smita. "Identification of Stress-Responsive Genes in the Early Larval Stage of the Fathead Minnow Pimephales Promelas." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1134665105.
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Almeida, Mara Cristina [UNESP]. "Desenvolvimento ontogenético larval e variabilidade populacional de Pimelodus britskii em um reservatório neotropical." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143104.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Pimelodus britskii, uma espécie endêmica da bacia do rio Iguaçu, apresenta poucos estudos que envolvam desenvolvimento ontogenético e parâmetros populacionais, deste modo, trabalhos que envolvam esses caracteres são de suma importância, para tomada de medidas de uso e conservação da espécie. Neste trabalho abordamos, no primeiro artigo, o desenvolvimento larval, proporções corporais e subsídios para diferenciar a larva nas fases iniciais de desenvolvimento das suas congenéricas. No segundo artigo avaliamos as modificações, ao longo do espaço e do tempo, com relação à abundância, proporção sexual, tamanho de primeira maturação, comprimento médio, relação peso/comprimento, e atividade reprodutiva. Em relação às larvas, inicialmente a pigmentação era escassa e intensificou-se com o desenvolvimento. O comprimento padrão variou de 2,6 a 13,11mm e os miômeros de 34-50. A espécie apresentou alometria negativa do comprimento da cabeça, altura do corpo, distância pré-dorsal e distância pré-anal em relação ao comprimento padrão e altura da cabeça, comprimento do focinho e diâmetro do olho em relação a comprimento da cabeça, e as estruturas corporais em todas as fases larvais de desenvolvimento são cartilaginosas. Foram capturados na totalidade 9.204 indivíduos, em quatros locais diferentes de coletas em 9 (nove) etapas. Evidenciou que a população de P.britskii, por diferentes etapas e locais, apresentou diferença significativa em seus parâmetros populacionais. A maior abundância (CPUE) ocorreu na etapa I e na estação de coleta Cavernoso (Cav). O comprimento médio da população variaram 15,5±6,2 cm, sendo os indivíduos maiores capturados na Etapa III e na estação de coleta Iate Clube Candói (Iat). O crescimento foi alométrico negativo, como o melhor fator de condição (K), encontrado na etapa III e na estação Iat, como ocorreu também para o comprimento médio. O índice de atividade reprodutiva (IAR), na escala temporal foram mais intenso na etapa I e no espaço na estação Cav. E em relação a diferentes estações de coleta, foram mais intenso nas estações quente (verão) e praticamente nulo na estações mais frias (outono). Considerando estes resultados podemos inferir que a população apresenta tendência à estabilização.
Pimelodus britskii, an endemic species of Iguaçu River basin, has scarce studies involving ontogenetic development and population parameters. So studies involving these characters are of great importance to take protection e conservation measures. This study presents, in the first paper, body proportions and subsidies to differ larval initial developing phases larval of its congenerics. The second paper evaluated changes, over space and time, related to abundancy , sexual proportion, first maturation size, medium lengh , weight /size relation and productive activity. The larvae initially pigmentation was scarce and intensified with the development, the standard length ranged from 2.6 to 13.11mm and myomeres from 34-50. The findings showed negative head length allometry, body height, predorsal length and pre-anal distance from the standard length and head height, snout length and diameter of the eye in relation to head length and structures in all larval stages of development are cartilaginous. 9.204 individuals were captured in nine years in four different collection places. It showed that the population of P.britskii, through different stages and places significant difference in their population parameters. The highest abundance (CPUE), occurred in stage I and Cavernous collection station (Cav). The average length of the population ranged 15.5 ± 6.2 cm, with the largest individuals caught in Stage III and gathering station Candói Yacht Club (Iat). The allometric growth was negative as the best condition factor (K) found in step III and Iat station as also observed for the mean length. The reproductive activity index (IAR), the temporal scale were more intense in stage I and space in Cav station. And in relation to different collection stations were more intense in the warm seasons (summer) and virtually nil in colder seasons (autumn). Considering these results we can conclude that the population has a tendency to stabilize.
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Lyncker, Lissa. "Abundance and Distribution of Early Life Stage Blue Crabs (Callinectes sapidus) in Lake Pontchartrain." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/848.
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I conducted a 12-month study of near-shore habitats in Lake Pontchartrain to assess spatiotemporal variation in the abundance of early life stage blue crabs (Callinectes sapidus). Collections were made using a 1 m2 throw trap and data showed that C. sapidus numbers varied over time and among sites. Two recruitment events occurred during the study. During the first recruitment in May-June, C. sapidus entered Lake Pontchartrain via the Inner Harbor Navigational Canal. In September-October, C. sapidus entered the Lake Pontchartrain via the Rigolets and Chef passes. My data suggest that C. sapidus utilize water circulation within the Lake Pontchartrain as a means of transportation throughout the estuary. MODerate-resolution Imaging Spectroradiometer (MODIS) 250 m data were analyzed to gain a large-scale view of suspended sediments patterns within Lake Pontchartrain and quantify water movement. Field sampling along with remote sensing proved to be beneficial when assessing estuarine-wide C. sapidus post-larval dispersal processes.
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Foulon, Valentin. "Etude du phénomène d'adhésion chez la larve d'huître creuse Crassostrea gigas au stade pédivéligère." Thesis, Brest, 2018. http://www.theses.fr/2018BRES0094/document.
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Les huîtres présentent un cycle de vie en deux phases : les larves pélagiques s’adhérent avant de se métamorphoser pour une vie benthique.L’adhésion larvaire se fait au stade pédivéligère par sécrétion d’un bioadhésif produit par un organe spécialisé : le pied. Bien que l’huître Crassostrea gigas soit un organisme d’importance économique et écologique, et un modèle d’étude en biologie marine, le phénomène d’adhésion chez la larve pédivéligère est peu documenté. Une étude morphologique des larves pédivéligères par histologie et microscopie électronique a été réalisée, afin de décrire les glandes responsables de la sécrétion de l’adhésif. Une composition majoritairement protéique de l’adhésif a été révélée par histochimie et spectroscopie FTIR.Une analyse in silico des données transcriptomiques disponibles chez C. gigas a permis d’identifier des gènes probablement impliqués dans l’adhésion.Deux analyses protéomiques, menées sur les larves entières et l’adhésif sécrété ont permis de caractériser des protéines en lien avec la biosynthèse et la structure de l’adhésif. Une protéine de type collagène apparaît impliquée dans la structure de l’adhésif de C. gigas. Cette première approche de l’étude de l’adhésion de C. gigas, permet d’envisager la valorisation biotechnologique des molécules identifiées. Le développement d’adhésifs biomimétiques, élaborés sur le principe des bioadhésifs marins, autoriserait le collage en milieu humide, et serait une alternative aux adhésifs synthétiques qui malgré leur toxicité, dominent le marché mondialOysters show a two-phase life cycle: pelagic larvae adhere before metamorphosis into benthic life. Larval adhesion occurs at the pediveliger stage by secretion of a bioadhesive produced by a specialized organ: the foot. The oyster Crassostrea gigas is an organism of economic and ecological importance, and a model for study in marine biology, but the phenomenon of adhesion in the pediveliger larvae is poorly documented. A morphological description of the pediveliger larvae by histology and electron microscopy was performed to describe the glands responsible for the secretion of the adhesive.A predominantly proteinaceous composition of the adhesive was revealed by histochemistry and FTIR spectroscopy. An in silico analysis of available transcriptomic data from C. gigas was made to identify genes probably involved in adhesion. Two proteomic analyses, performed on whole larvae and on the secreted adhesive, characterizing proteins related to biosynthesis and adhesive structure. A collagen-like protein appears to be involved in the adhesive structure of C. gigas. This first approach to the study of the adhesion of C. gigas makes it possible to consider the biotechnological enhancement of the identified molecules. Despite their toxicity, synthetic adhesives dominate the world market. The development of biomimetic adhesives, based on marine bioadhesive strategies could be an alternative, and allowing furthermore bonding in wet condition
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Walsh, Harvey Joseph. "Distribution of fall / winter-spawned larval fish in relation to hydrographic fronts on the North Carolina shelf implications for larval transport mechanisms /." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-06262007-095953/.
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Fish population dynamics are partially determined by successful larval transport. Many fish in the southeast U.S. use estuaries as juvenile nursery habitat, but are spawned on the continental shelf. Favorable cross-shelf larval transport pathways for fall / winter-spawned species off North Carolina have been theorized to occur as a result of seasonal circulation patterns of currents and episodic onshore movement of water masses. As a result, hydrographic fronts which separate the water masses; including the outer-shelf front and mid-shelf front have been linked to cross-shelf larval transport for several species. The objective of this study was to determine whether fronts on the continental shelf off the southeast U.S. influence larval fish distribution and cross-shelf transport. Ichthyoplankton and hydrographic data were analyzed in concert to determine if the presence of fronts on the shelf influenced larval distribution patterns or mean distance from shore of larvae. In addition, ?average? larval distribution patterns for each species were compared with the results from when fronts were present. Results indicated larval fish were not aggregated at fronts, though abundance and size distribution patterns and mean distance from shore of several species-size classes analyzed were significantly different when the outer-shelf front, mid-shelf front, warm Gulf Stream filament front, or Hatteras front (i.e., intrusions of Virginia coastal water) were present on the shelf. Average cross-shelf distributions of several species were similar to previous studies which led to the conclusion that cross-shelf larval transport was predominately driven by seasonal circulation patterns; however, present results verify that episodic events, such as fronts modify seasonal transport pathways.
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Delves, C. J. "Developmental processes in filarial worms." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377098.
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Reed, James Edward. "Characterisation of secretion in the infective stage larvae of filarial nematodes." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343693.
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Boerseth, Cathrine. "Spatial dynamics and characterization of the ichthyoplankton community of natural and artificial reef environments on the coast of Paraná state, south Brazil." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/21/21134/tde-19122016-164859/.
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Artificial reefs (ARs) have been deployed on the inner shelf of Paraná State, south Brazil, to recuperate marine biodiversity and as protection against destructive trawling activities. The purpose of this study was to offer a first characterization of the ichthyoplankton community associated with the ARs and the adjacent archipelago of Currais. Two sampling methodologies were used; 1) plankton net attached to an underwater scooter and; 2) light-traps. A hydrodynamic model was used to study dispersal trajectories to and from the study area. Sampling was conducted between 31.07.14 and 04.04.16. A total of 13 families and 11 species were identified, expanding the total species list of the study area with six species and four families; 63% of fish larvae caught on the ARs were of reef associated species; abundance and species richness was higher on the ARs compared to samples taken at a distance from the ARs. First occurrence of the invasive muzzled blenny Omobranchus punctatus was registered. The hydrodynamic model provided insight on dispersal trajectories and connectivity. The results of this study can be used to better define guidelines for sustainable use of the ARs and the Currais archipelago, a Marine National Park since 2013.Recifes Artificiais (RA) foram implantados na plataforma interna do Paraná, sul do Brasil, para atuar como unidades anti-arrasto e para oferecer habitat e abrigo para a fauna local, na tentativa de recuperar a biodiversidade marinha ameaçada pelo pesca de arrasto. O principal objetivo deste estudo foi oferecer uma primeira caracterização da assembleia ictioplanctônica associada aos RAs e ao arquipélago de Currais. Coletas foram realizadas utilizando duas metodologias; 1) rede de plâncton acoplado a uma \"scooter\" subaquática e; 2) armadilhas de luz. Excursões amostrais foram realizadas entre 31.07.14 e 04.04.16. Um total de 13 famílias e 11 espécies de peixes representadas no ictioplâncton foram identificadas. Foi registrada a primeira ocorrência do blenídeo invasivo Omobranchus punctatus. A abundância de ictioplâncton foi maior em amostras dos RAs comparado às coletas em área-controle; 63% das larvas capturadas nos RAs foram de espécies recifais. Um modelo hidrodinâmico forneceu uma visão sobre as trajetórias de dispersão larval e conectividade ecológica na região. Os resultados deste estudo podem ser usados para melhor definir diretrizes para o uso sustentável dos RAs e do arquipélago de Currais, um Parque Nacional Marinho desde 2013.
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Ménard, Louise. "Aspects of the ecology of the larval stages of Cyathocotyle bushiensis Khan 1962 (Digenea)." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66176.
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Medrano, Jennifer Centurion. "Chemotactic Response of Lumbricus terrestris Coelomocytes to Larval and Adult Stages of Rhabditis pellio." Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc5507/.
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Experiments were performed to assess the suitability of Rhabditis pellio, a nematode found in earthworms, as a challenge organism for use in development of a biomarker assay to determine the potential of chemicals to suppress the immunocompetence of the non-specific immune system. To accomplish this goal, information on the life cycle of R. pellio was determined; including effects of incubation time and temperature on growth rates; along with information on the immune response elicited in the earthworm, Lumbricus terrestris. Immune parameters measured were coelomocyte migration toward and attachment to R. pellio larvae and adults. Preliminary background information showed that R. pellio has potential as a challenge organism for development of a biomarker assay.
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Albright, Rebecca. "Effects of Ocean Acidification on Early Life History Stages of Caribbean Scleractinian Corals." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/574.
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Ocean acidification (OA) refers to the increase in acidity (decrease in pH) of the ocean’s surface waters resulting from oceanic uptake of atmospheric carbon dioxide (CO2). Mounting experimental evidence suggests that OA threatens numerous marine organisms, including reef-building corals; however, few studies have focused on the effects on early life history stages. Coral recruitment is critical to the persistence and resilience of coral reefs and is regulated by several early life processes, including: larval availability (gamete production, fertilization, etc.), larval settlement, post-settlement growth, and survival. Environmental factors that disrupt these early life processes can result in compromised or failed recruitment and profoundly affect future population dynamics. To evaluate the effects of OA on the sexual recruitment of corals, sexual reproduction (including fertilization and sperm swimming speeds) and several critical early life history stages (including larval metabolism, larval settlement, and post-settlement growth) were tested in common Caribbean coral species. Three pCO2 levels were used: ambient seawater (380 µatm) and two pCO2 scenarios that are projected to occur by the middle (560 µatm) and end (800 µatm) of the century as determined by the Intergovermental Panel on Climate Change. Results show that fertilization success, larval metabolic rates, larval settlement rates, and post-settlement growth rates are all compromised with increasing pCO2. This dissertation demonstrates that OA has the potential to negatively impact sexual reproduction and multiple early life history processes of several common Caribbean coral species and may contribute to substantial declines in sexual recruitment that are felt at the community and/or ecosystem scale.
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Hopkins, Susan Marian. "Studies on survival and development of the larval stages of the trichostrongyle nematode "Nematospiroides dubius." Thesis, Royal Holloway, University of London, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.549680.
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Chiu, Man Ying. "Biological and ecological processes that intervene the larval and juvenile stages of the gastropod crepidula onyx /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202007%20CHIU.
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Duro, Lia Susana Lourenço Simões. "Parasitismo gastrintestinal em animais da Quinta Pedagógica dos Olivais. Especial referência aos mamíferos ungulados." Bachelor's thesis, Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária, 2010. http://hdl.handle.net/10400.5/2624.
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Dissertação de Mestrado Integrado em Medicina VeterináriaO presente estudo resultou do trabalho realizado durante e após o estágio curricular do Mestrado Integrado em Medicina Veterinária, na Quinta Pedagógica dos Olivais, no concelho de Lisboa. Numa primeira parte desta dissertação, efectuou-se uma monografia, relativa às parasitoses gastrintestinais mais relevantes dos mamíferos ungulados (suínos, bovinos, pequenos ruminantes e equídeos). Quanto à segunda parte desta dissertação, consistiu num estudo de campo e de laboratório sobre as parasitoses gastrintestinais do efectivo de mamíferos ungulados na Quinta Pedagógica dos Olivais. No referido estudo, foram assinalados estrongilídeos gastrintestinais em ovinos, caprinos, suínos e equídeos. Os picos mais elevados de Ovos por Grama de fezes (OPG) de estrongilídeos gastrintestinais nos ruminantes e nos equídeos verificaram-se no final de Janeiro e início de Fevereiro de 2009. No que respeita aos equídeos, foram identificados, através de coproculturas, larvas infectantes de Cyathostomum spp. (53%), Strongylus vulgaris (34%), Trichostrongylus axei (9%), Triodontophorus spp. (2%), S. edentatus (1%) e Gyalocephalus capitatus(1%). Relativamente aos pequenos ruminantes, foram encontradas, nas coproculturas, larvas de Ostertagia sp., Trichostrongylus sp., Haemonchus sp. Cooperia sp., Nematodirus sp., Chabertia/Oesophagotomum sp. e Bunostomum sp. Nos ovinos, os parasitas que apresentaram uma maior frequência relativa média foram Cooperia sp. (30%), Ostertagia sp.(21,3%) e Haemonchus sp.(22,5%) e nos caprinos foram Cooperia sp.(51%), Ostertagia sp.(22,4%) e Haemonchus sp.(10,5%). Nas coproculturas dos pequenos ruminantes apenas foi observada uma larva de Bunostomum sp. nos ovinos. Foram identificados ovos do tipo estrongilídeo nos exames qualitativos das amostras fecais dos suínos e dos bovinos, ainda que não tenham sido observadas quaisquer larvas infectantes nas coproculturas. A Taxa de Redução de Ovos dos ovinos e dos caprinos, 20 dias após a desparasitação com Febendazol (Panacur®), foi de 100%. A Taxa de Redução de Ovos do muar, após desparasitação com 0,2 mg de Ivermectina/Kg PV PO SID (Eqvalan®), foi de 100%. Foi ainda estudada a população de larvas infectantes das pastagens da referida Quinta Pedagógica dos Olivais, ocorrendo o pico mais representativo de L3/kg erva seca no mês de Dezembro de 2008.
ABSTRACT - Gastrointestinal parasitism in animals of the Olivais’ Pedagogical Farm. Special reference to Ungulate Mammals. - This study was the result of the research developed during and after the training course of the Integrated Master in Veterinary Medicine at the Olivais’ Pedagogical Farm in the municipality of Lisbon. In the first part of this work, a bibliographic review was carried out on the most important gastrointestinal parasites of ungulate mammals (pigs, cattle, small ruminants and horses). The second part of this work consisted of a field and laboratory study of gastrointestinal parasites of the livestock, namely ungulate mammals at the Olivais’ Pedagogical Farm. In this study, gastrointestinal strongyles were reported in sheep, goats, pigs and horses. The highest peaks of eggs per gram of faeces (EPG) of gastrointestinal strongyles in ruminants and horses were found in the end of January and early February 2009. In the case of horses, infective larvae of Cyathostomum spp. (53%), Strongylus vulgaris (34%), Trichostrongylus axei (9%), Triodontophorus spp. (2%), S. edentatus (1%) and Gyalocephalus capitatus (1%) were identified through faecal cultures. For small ruminants, larvae of Ostertagia sp., Trichostrongylus sp., Haemonchus sp. Cooperia sp., Nematodirus sp., Chabertia / Oesophagotomum sp. and Bunostomum sp. were found in the faecal cultures. In sheep, the parasites showing higher frequency were Cooperia sp. (30%), Ostertagia sp. (21.3%) and Haemonchus sp. (22.5%) and in goats those parasites were Cooperia sp. (51%), Ostertagia sp. (22.4%) and Haemonchus sp. (10.5%). In the faecal cultures of small ruminants only one larval stage of Bunostomum sp. was observed in sheep. Although strongyle type eggs were identified in the qualitative tests, infective larvae were not observed in faecal cultures of the fecal samples of pigs and cattle. The Faecal Egg Count Reduccion Test in sheep and goats, 20 days after deworming with Fenbendazole (Panacur ®), was 100%. The Faecal Egg Count Reduccion Test in mule, after deworming with Ivermectin 0.2 mg / kg PO SID BW (Eqvalan ®), was 100%. The population of infective larvae from pasture of Olivais’ Pedagogical Farm was also studied in this work and a marked peak of L3/kg dry herbage was observed in December 2008.
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Bruno, Trezia Ieda Ballerini. "Infecção de Biomphalaria glabrata com Angiostrongylus costaricensis : desenvolvimento larval e resposta hemocitaria." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314681.
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Orientador: Eliana Maria Zanotti-MagalhãesTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Experimentalmente, Biomphalaria glabrata pode ser utilizada como hospedeiro intermediário do nematódeo Angiostrongylus costaricensis, responsável pela angiostrongilíase abdominal. Esta zoonose, descrita no Brasil principalmente nos estados sulinos, pode acometer acidentalmente o homem, sendo que a infecção ocorre através da ingestão de moluscos parasitados ou água e alimentos contaminados com larvas de 3° estágio, eliminadas no muco dos moluscos hospedeiros. O objetivo deste trabalho foi estudar o desenvolvimento dos estágios larvais e o comportamento dos hemócitos na hemolinfa de B. glabrata infectada.Um total de 168 moluscos foi infectado com 120 larvas LI de A. costaricensis extraídas das fezes de camundongos Swiss albinos previamente infectados via oral sob tubagem esofágica com 6 larvas L3. Larvas de A. costaricensis foram recuperadas de 45 moluscos B. glabrata após 15, 22 e 29 dias de exposição ao parasita, através do método de Baermann, utilizando tecidos digeridos dos moluscos com solução de pepsina e ácido clorídrico. Constatou-se maior recuperação de larvas de A. costaricensis dos moluscos aos 29 dias de infecção. Para o estudo do desenvolvimento de Ao costaricensis, 60 moluscos infectados foram destinados a recuperação larval durante 30 dias consecutivos. Foi observada a mudança larval de LI para L2 aos 13 dias de infecção e L2 para L3 aos 18 dias de infecção. Hemolinfa de 45 moluscos infectados e não infectados com A. costaricensis foi coletada para verificação da resposta hemocitária durante 4 semanas. Os hemócitos foram distinguidos em hialinócitos e granulócitos. Enquanto nos moluscos não infectados predominaram os hialinócitos, naqueles infectados os granulócitos foram mais evidentes, principalmente entre o 18° ao 25° dia de infecção. Foi confirmada a ocorrência tanto da infecção percutânea como por via oral. Os locais mais parasitados foram: região cefalopodal, a preferida pelo nematódeo, seguida do intestino, rim e pulmão. Todas as larvas encontradas estavam viáveis e rodeadas por reação do tipo granulomatosa, independentes de sua localização
Abstract: Biomphalaria glabrata can be experimentally used as an intermediate host of the nematode Angiostrongylus costaricensis, responsible for abdominal angiostrongyliasis. This zoonosis, found in Brazil mainly in the southem states, can accidentally infect man through the ingestion of parasitized mollusks or contaminated water and food containing third-stage larvae, eliminated in the mucous secretion of the mollusks. The objective of this work was to study the development of larval stages and the behavior of hemocytes in the hemolymph of infected B. glabrata. A total of 168 mollusks were infected with 120 LI larvae of A. costaricensis, extracted ftom excrement of albino Swiss mice previously infected via the oral route by esophageal tube with 6 L3 larvae. The A. costaricensis larvae had been recovered from 45 B. glabrata mollusks at 15, 22 and 29 days after exposure to the parasite, by means of the method of Baermann, using molluscan tissues digested with pepsin and hydrochloric acid solution. A larger recovery of A. costaricensis larvae from the mollusk was found at 29 days after infection. For the study of the development of A. costaricensis, 60 infected mollusks were allocated for larval recovery during a period of 30 consecutive days. It was observed that there was a larval stage change, from L1 to L2, at the 13th day after infection and from L2 to L3 on the 18th day after infection.The hemolymph of 45 mollusks, both infected and not infected with A. costaricensis, was collected for verification of the hemocyte response during 4 weeks. The hemocytes were differentiated into hyalinocytes and granulocytes. While in the non infected mollusks the hyalinocytes had predominated, in those infected granulocytes were more evident, mainly between the 18th and the 25th day after infection. The occurence of infection, both via percutaneous and via oral routes, was confirmed. The most parasitized sites were the cephalopodan mass, preferred by the nematodes, folIowed by the intestines, kidneys and lungs. AlI the larvae found were viable and surrounded by reaction of the granulomatous type, independent of their situation
Doutorado
Mestre em Parasitologia
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Chism, Billy Dell. "Laboratory evaluation of the horizontal movement of pyriproxyfen to larval microcosms by gravid Aedes albopictus (Skuse) and Aedes triseriatus (Say)." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010530-101221.
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Horizontal movement of the insect growth regulator (IGR) pyriproxyfen to larval microcosms by gravid container-inhabiting mosquitoes, Aedes albopictus (Skuse) and Aedes triseriatus Say, was evaluated under laboratory conditions. In larval susceptibility bioassays determining emergence inhibition (EI), both species were found to be highly susceptible to the IGR. Aedes albopictus exhibited an EI50 of 0.200 ppb, while Aedes triseriatus was 7 and 3.5x more susceptible with an EI50 of 0.0288 ppb. A randomized complete block experimental design was used for each species to evaluate the horizontal transfer of the IGR by gravid females force contacted with pyriproxyfen-treated oviposition strips. For Ae. albopictus, experiments were blocked by treatment rate of pyriproxyfen (0.2, 0.3 and 0.4 mg/cm2). Effects of numbers of treated females (1, 3 and 5 females per bioassay cage) on horizontal movement of the IGR was evaluated within each treatment rate. One treatment rate of pyriproxyfen (0.2 mg/cm2) was evaluated for Ae. triseriatus. A significant (P<0.05) curvilinear response in emergence inhibition was observed in Ae. albopictus and Ae. triseriatus over the three population densities of treated females evaluated. Notably, the shape of the response curves for the two species were opposite. Lower but equivalent levels of mortality were achieved at densities of 1 and 3 treated Ae. triseriatus females per cage with significantly higher levels of inhibition of emergence observed at 5 females per cage. At 1,3, and 5 females per cage, mortality of Ae. triseriatus averaged 20.8%, 26.9%, and 70.4%, respectively. For Ae. albopictus, mortality at the higher two population densities was similar and significantly larger than was observed at the lowest population density. Mean mortality of Ae. albopictus ranged over the 3 treatment rates from 3.5 to 30.2%, 47.8 to 67.3%, and 58.6 to 73.1% at densities of 1,3 and 5 females per cage, respectively. Amounts of pyriproxyfen transferred by gravid females were estimated from the log dose-probit mortality data obtained in larval bioassays.In binary choice bioassays, horizontal transfer of biologically active amounts of pyriproxyfen from treated (0.3 or 0.4 mg/cm2) to untreated microcosms was achieved by Aedes albopictus. Three microcosm configurations were utilized in an attempt to manipulate mosquito oviposition behavior to increase the amount of IGR transferred. Emergence inhibition (37.8%) for microcosms completely wrapped in black paper was significantly higher (P>0.05) than two other configurations utilized. Forcibly exposing gravid females to pyriproxyfen-treated surfaces did not affect their fecundity. However, mean percent egg hatch between egg clutches laid in the 1st and 2nd gonotrophic cycles declined significantly (P<0.05) by 30%. To assess the residual activity of pyriproxyfen, 1st instar Ae. albopictus were added to microcosms used in forced-contact experiments. Mosquito mortality declined markedly indicating that pyriproxyfen was not highly residual in larval microcosms. Use of IGR-treated oviposition containers to achieve horizontal movement of pyriproxyfen to mosquito oviposition sites in the field is a promising management technique. However, laboratory results were often variable, suggesting that interactions between females within the oviposition site caused a differential transfer of pyriproxyfen to larval microcosms. Comparative studies of the oviposition behavior of each mosquito species are warranted and would potentially provide information needed to improve the technique.
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Gregory, William Francis. "Cloning and characterisation of genes expressed by the third stage larvae of the parasitic nematode Brugia malayi." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/14953.
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Reverse transcription polymerase chain reaction (RT-PCR) of RNA from the infective larval stages of Brugia malayi with the nematode-specific 5' spliced leader sequence and oligo d(T) has been used to identify genes expressed during early larval stages. Products resolved on agarose gels show a number of prominent bands and cloning of these bands has revealed a total of 14 genes. Of these, four genes have been analysed in detail. One highly stage-specific transcript Bm-cpi-1, a cystatin-type cysteine proteinase has been characterised in parallel to a second, constitutively expressed, cystatin, Bm-cpi-2, identified by EST sequencing. The two inhibitors have been functionally expressed in E. coli and have distinct inhibitory specificities. In addition, both CPIs have been localised to the parasite surface and found in parasite secretions. An abundant transcript, Bm-alt-1, is a member of a large family of genes found in nematodes but lacks clear homologues outside the nematode phylum. Analysis of Expressed Sequence Tags (ESTs) deposited in dbEST has identified a total 10 family members in B. malayi. Genomic structures of the two most abundant family members have revealed conservation in the position of introns. However there is considerable sequence divergence within introns, with one gene containing distinct repeat units within its introns. In addition, heterogeneity is seen within this due to variation in the number of repeat units. Two further genes have been characterised. One is a homologue of the human histamine-releasing factor, a constitutively expressed, cytokine-like molecule of interest as a potential modulator of antiparasite responses. A second is a member of a family of proteins of unknown function, rich in glycine and tyrosine residues, which may form part of the nematode cuticle. The discovery of these abundant genes provides candidates for future analysis of immune evasion by filariae and identifies potential targets for vaccination or chemotherapy.
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Silver, Gregory Shell. "Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2358.
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Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range.
We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat.
Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances.
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Paula, Salete de. "Caracterização do desenvolvimento larval do pacu, Piaractus mesopotamicus (Holmberg, 1887): morfometria e crescimento isométrico." Universidade Estadual do Oeste do Parana, 2012. http://tede.unioeste.br:8080/tede/handle/tede/733.
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Previous issue date: 2012-09-24Fundação Araucária
This study describes the development and allometric growth patterns of larval Piaractus mesopotamicus from induced reproduction. From hatching until the 19th day, twenty individuals were selected for eight stage of development (yolk sac larval, preflexion, initial of flexion, flexion, end of flexion and post flexion). Later, morphometric measurements were taken of each individual: total length, head length, trunk length, tail (post anal) length, head height, body height, muscle height at anus leveleye diameter, mouth length, caudal peduncle height and caudal peduncle length. Allometric growth coefficients were calculated by linear regression; the changes in the coefficients of growth relate to ontogenetic changes in the priorities of the larvae. During the developmental stages of larval yolk and pre-flexion (mean CT = 3.363 and 5.89 mm), the larvae showed an evident priority for feeding and swimming capabilities. From the flexion stage (mean CT = 9.33 mm) was observed a change in growth priorities, especially those relating to body height, important characteristic for this species. From the post-flexing stage (mean CT = 16.25 mm) a greater propensity to isometry was evident for all coefficients growths. These results confirm the informations that there are different growth patterns for priority functions during ontogeny initial larvae. This study of morphometric and allometric growth of larvae Piaractus mesopotamicus, may assist the fisheries biology, supporting management strategies and conservation of natural populations
Este estudo descreveu o desenvolvimento e os padrões de crescimento alométrico de larvas de Piaractus mesopotamicus provenientes de reprodução induzida. Desde a eclosão até o 19° dia, vinte indivíduos foram selecionados para oito estágios de desenvolvimento (larval vitelino, pré-flexão, início de flexão, flexão, final de flexão, início de pós-flexão, pós flexão e final de pós-flexão). Posteriormente, foram tomadas medidas morfométricas: comprimento da cabeça, comprimento do tronco, comprimento da cauda anal posterior, altura da cabeça, altura do corpo, altura do músculo em nível do ânus, diâmetro do olho, comprimento da boca, altura do pedúnculo caudal e comprimento do pedúnculo caudal. Os coeficientes de crescimento alométrico foram calculados por meio de regressões lineares; as alterações ocorridas nos coeficientes de crescimento referem-se as mudanças nas prioridades ontogenéticas das larvas. Durante os estágios de desenvolvimento de larval vitelino e pré-flexão (média CT= 3,36 e 5,89 mm) as larvas apresentaram uma evidente prioridade para as capacidades de alimentação e natação. A partir do estágio de flexão (média CT= 9,33 mm) foi observada uma mudança nas prioridades de crescimento, principalmente as relacionadas com a altura do corpo, característica importante para essa espécie. No estágio de pós-flexão (média CT=16,25 mm) uma propensão maior a isometria ficou evidente, para todos os coeficientes de crescimentos. Esses resultados confirmam as informações de que existem padrões diferenciados de crescimento para funções prioritárias durante a ontogenia inicial de larvas. Este estudo sobre morfometria e crescimento alométrico das larvas de Piaractus mesopotamicus, poderá auxiliar a biologia pesqueira, subsidiando as estratégias de manejo e conservação das populações naturais
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Balfour, David Leigh. "Ontogenetic Changes and Environmental Hypoxia: Responses of Two Fish Species to Low Oxygen Concentrations at Early Life Stages." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/26467.
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Hypoxia refers to any condition in which the water is less than fully saturated with oxygen. Although it is generally accepted that adults are more tolerant of hypoxic conditions than larval stages, there is little information to support this assumption. To determine whether reduced concentrations of dissolved oxygen (DO) affect fishes differently during various early life stages, I examined the responses of two species of fish (fathead minnows (Pimephales promelas) and rainbow trout (Oncorhynchus mykiss)) exposed to low dissolved oxygen concentrations at different ages during the first 100 days post-hatch.
The changes in oxygen requirements and respiratory patterns that occur during ontogeny and exposure to hypoxia were observed. The results of this study suggest that the early larval stages appear to be at least as tolerant of short-term exposure to low dissolved oxygen concentrations as the older, more developed stages. Fathead minnows underwent a gradual transition from being metabolic conformers to regulators during development. Hemoglobin appeared to be playing a larger role in oxygen supply in the early post-hatch trout than in the minnows. Fathead minnow larvae produced relatively low concentrations of lactate upon exposure to hypoxia. Conversely, rainbow trout larvae exhibited significant increases in lactate concentration under similar conditions. This implies that there is a threshold oxygen concentration below which trout larvae utilize anaerobic metabolism to provide additional energy. Lactate dehydrogenase activity increased as the rainbow trout larvae aged, suggesting that they develop an anaerobic capacity which could be used to provide additional energy during hypoxia. The minnows did not exhibit this increase in activity.
The ability of larval fishes to detect and avoid hypoxic conditions was also examined. The overall trends suggest that throughout this period of development, both fish species gradually leave an area as the dissolved oxygen concentration decline. Both species appeared to leave the hypoxic areas with deliberate motions, indicating that a directed sensor system allowed them to detect oxygen gradients. The results suggest that a combination of physiological, biochemical, and behavioral mechanisms may allow fishes to cope with hypoxia.Ph. D.
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Daniels, Carly. "Optimisation of the rearing diets for early life stages of the European lobster, Homarus gammarus, to enhance growth, survival and health using biotic dietary supplements." Thesis, University of Plymouth, 2011. http://hdl.handle.net/10026.1/551.
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The series of experiments that comprises this thesis consider the use of prebiotics and probiotics to improve success in European lobster Homarus gammarus culture. Research was conducted at the National Lobster Hatchery and The University of Plymouth, UK between April 2007 and March 2010. Great potential was revealed for the application of biotics as dietary supplements in the culture of larval and juvenile H. gammarus. Specific biotics, namely; prebiotic mannon oligosaccharide (MOS) and probiotic Sanolife® (Bacillus spp.) were revealed to increase growth and survival during the culture of early lobster life stages. Lobsters that showed enhanced development and/or survival were found to possess improved feed conversion, immune status and/or stress tolerance. Furthermore it was found that biotic fed lobsters displayed shifts in gastrointestinal (GI) microbiology and enhanced physical GI structures, which may account for improved feed conversion and consequently growth. The work presented thus demonstrates that by making positive changes in GI structure and bacterial community composition combined with influencing immune status culture success can be positively enhanced through the biotic supplementation of diets. However, it must be considered that the outcome of dietary biotic supplementation is heavily influenced by the situation in question.
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Smith, Kent James. "Enhanced Cold Tolerance of Diapause-Destined vs Non-Diapause-Destined Larval Stages of the Flesh Fly, Sarcophaga Crassipalpis(Diptera: Sarcophagidae)." Oxford, Ohio : Miami University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1172780125.
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Thoday, A. "Studies on the ultrastructure of the pituitary of a non parasitic lamprey Lampetra planeri throughout the larval, metamorphosing and adult stages." Thesis, Open University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380056.
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Lopes, Bruno de Sousa. "História natural e performance larval de Oospila pallidaria (Schaus, 1897) (Lepidoptera, Geometridae, Geometrinae): uma mariposa esmeralda do Cerrado." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/59/59131/tde-20072016-181713/.
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São estimadas 90 mil espécies de insetos para o Cerrado, o segundo maior bioma brasileiro, com enorme heterogeneidade de habitats e rica fauna. Dentre esses insetos, os Lepidoptera representam cerca de 10% do total de espécies. Entretanto, estudos sobre seus imaturos (ovo, larva e pupa) ainda são incipientes para o bioma, principalmente sobre as mariposas, cujas histórias naturais de muitas espécies ainda são desconhecidas. A falta desses estudos faz com que sejam ignoradas as interações multitróficas em que esses organismos estão envolvidos e, portanto, inviabiliza futuros estudos relacionados ao seu papel em comunidades e redes ecológicas. Esse é o caso de muitas espécies da família Geometridae, incluindo Oospila pallidaria, que é uma mariposa esmeralda (devido à coloração verde esmeralda das suas asas). Oospila pallidaria é uma espécie herbívora que não possuía até o momento nenhuma informação publicada sobre a sua biologia e fatores que condicionam sua ocorrência, tais como: a fenologia da planta hospedeira, que pode determinar o período de melhores condições para crescimento e reprodução; a qualidade nutricional dos recursos alimentares (e. g. quantidade de água e nitrogênio), que pode determinar quais recursos conferem melhor desenvolvimento/performance a um herbívoro; os inimigos naturais, que podem restringir a ocorrência dos herbívoros e a temperatura e pluviosidade, que podem alterar a qualidade e a distribuição geográfica dos recursos alimentares utilizados pelos herbívoros. Nesse sentido, o objetivo principal deste estudo foi descrever, pela primeira vez, aspectos da biologia e história natural de O. pallidaria (Capítulo 1) e avaliar a sua performance larval, a partir de diferentes dietas (Capítulo 2). Os resultados apresentados no Capítulo 1 mostraram que os ovos de O. pallidaria, verdes e com duração média de sete dias, foram solitários e ovipostos principalmente nos tricomas das folhas maduras. As larvas se alimentaram de folhas maduras predominantemente, mas utilizaram folhas jovens e botões florais oportunisticamente. As larvas tiveram coloração críptica, se camuflaram em meio às folhas de Mimosa setosa (Leguminosae: Mimosoideae), sua única hospedeira, e desenvolveram o comportamento de auto-limpeza. Há cinco ínstares larvais, com coloração que variou de amarelo a verde. As larvas apresentaram também um par de projeções no protórax e linha mediana marrom na região dorsal. O comprimento máximo do corpo das larvas foi de 28 mm. As pupas foram predominantemente verdes, com no máximo 10 mm de comprimento. O desenvolvimento do ovo ao adulto durou cerca de 50 dias ( = 42; S = 6; n = 11). Seu único inimigo natural registrado foi o microhimenóptero Cotesia sp. (Braconidae, Microgastrinae). Fêmeas de O. pallidaria produziram 65 ovos em média (S = 7,07; n = 2). A ocorrência de O. pallidaria foi sazonal e sobreposta ao pico de presença de folhas maduras. Larvas foram negativamente relacionadas à temperatura e pluviosidade, com significância estatística somente para a primeira (r = - 0.5889, P < 0.05). No Capítulo 2, foi mostrado que as folhas maduras de M. setosa foram o único recurso alimentar disponível durante todo o ano. Os botões florais foram o recurso com maior qualidade nutricional (conteúdo relativo de água e nitrogênio total), seguidos por folhas jovens e maduras respectivamente. Entretanto, a sobrevivência de O. pallidaria foi maior com folhas maduras. Os resultados indicam que para o herbívoro especialista O. pallidaria, a fenologia da planta hospedeira é crucial para sua sobrevivência, em especial a presença de folhas maduras de M. setosa. Por outro lado, os botões florais são recursos efêmeros, porém importantes para a sobrevivência das larvas de últimos ínstares no final da estação seca, quando as folhas maduras estão ressecadas e/ou senescentes.It is estimated 90.000 species of insects for the Cerrado, the second largest Brazilian biome, with great diversity of habitats and rich fauna. Among these insects, Lepidoptera represents about 10% of all species. However, studies on their immature stages (egg, larvae and pupae) are incipient for the biome, mostly on moths, whose natural histories of many species are unknown. The lack of these studies makes the multitrophic interactions in that these organisms are involved ignored and, therefore, prevent future studies related to their role in communities and ecological networks. This is the case of many species of Geometridae, including Oospila pallidaria, which is an emerald moth (due to emerald green color of their wings). Oospila pallidaria is a herbivorous species that had not published any information on their biology and factors that influence their occurrence, such as: the phenology of the host plant, which can determine the time of better conditions for growth and reproduction; the nutritional quality of food resources (e. g. amount of water and nitrogen), which can determine what resources provide better development/performance to a herbivore; natural enemies, that could restrict the occurrence of herbivores and the temperature and rainfall, which can change the quality and geographical distribution of food resources used by herbivores. Accordingly, the aim of this study was to describe, for the first time, aspects of the biology and natural history of O. pallidaria (Chapter 1) and to assess their larval performance from different diets (Chapter 2). The results presented in Chapter 1 showed that eggs of O. pallidaria, green and lasting an average of seven days, were lonely and laid especially in trichomes of mature leaves. The larvae fed on mature leaves predominantly, but used young leaves and flower buds opportunistically. Larvae had cryptic coloration, they camouflaged among the leaves of Mimosa setosa (Leguminosae: Mimosoideae), a single host, and developed the self-cleaning behavior. There are five larval instars, with color ranging from yellow to green. The larvae also had a pair of projections on prothorax and brown midline in the dorsal region. The maximum length of the larvaes body was 28 mm. The pupae were predominantly green, with a maximum of 10 mm in length. The development from egg to adult lasted about 50 days ( = 42, S = 6, n = 11). Their only natural enemy recorded was the microhymenopteran Cotesia sp. (Braconidae, Microgastrinae). Oospila pallidaria females produced 65 eggs on average (S = 7.07; n = 2). The occurrence of O. pallidaria was seasonal and overlapped on the peak presence of mature leaves. Larvae were negatively related to temperature and rainfall, with statistical significance only for the first (r = - 0.5889, P < 0.05). In Chapter 2, it was shown that mature leaves of M. setosa were the only food source available throughout the year. The flower buds were the resource with higher nutritional quality (relative water content and total nitrogen), followed by young and mature leaves respectively. However, the survival of O. pallidaria was greater with mature leaves. The results indicate that for the specialist herbivore O. pallidaria, the host plant phenology is critical for its survival, especially the presence of mature leaves of M. setosa. On the other hand, the flower buds are ephemeral resources, but important for the survival of the last instar larvae in the dry season, when mature leaves are withered and/or senescent.
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Richardson, Shanthini Devi. "Studies on the life-cycle of the digenetic trematode Rhipidocotyle campanula (Dujardin, 1845) (Gasterostomata: bucephalidae) with particular reference to the larval stages." Thesis, University of Leeds, 1990. http://etheses.whiterose.ac.uk/723/.
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The life-cycle of Rhipidocotyle campanula (Dujardin, 1845) has been experimentally demonstrated and the species identity confirmed. Sporocysts were recovered from digestive glands of the freshwater-mussel Anodonta anatina, and in heavily infected 'hosts from the reproductive, system. Both cercariae and glochidia are released simultaneously in mussels where the reproductive system is partly invaded by sporocyst tubules. The development of the cercariae in the sporocyst tubules has been studied briefly fusing histological and histochemical methods. The liberation of cercariae varied- between >1000/mussel/day to none, and is intermittent. Behaviour of the cercariae including swimming, response to light and gravity, survival and entry, into the secondary host, is described. The morphology of the cercaria has been studied in detail using electron microscopy, histochemistry and histological methods and its significance analysed in relation to free-living existence. This is the first attempt to study the cercaria of R. campanula in any detail. Cercariae enter the secondary host passively and encyst in the subcutaneous fatty tissue beneath the lining of the pharynx, and in some cases in the gill arches. This is the only species of bucephalids where cercariae enter the secondary host passively. Encysted metacercariae attain maximum development after 5-6 weeks and survive nearly 200 days, but spontaneous excystation takes place only in cysts 80-90 days old. Adult flukes were recovered from the posterior intestine and rectum of the perch (Perca fluviatilis) six weeks after feeding fully developed metacercariae. Spermatogenesis and oogenesis were studied in the adults until egg formation. Miracidial development could not be observed. External morphology using SEM of cercaria, metacercaria and adult has been studied and compared. This is the first report of SEM study of these stages of R. campanula. A brief review of the literature is given and the problems of systematics and taxonomy of the family Bucephalidae the taxonomic position of R. campanula are discussed.Tabular summaries are given for the previous life-cycle studies of bucephalids, synopses of bucephalid trematodes and all previous reports of bucephalid cercariae.
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Garcia, Sara Marie. "Sublethal Effects of Crude Oil and Chemical Dispersant on the Eastern Oyster (Crassostrea virginica) at Multiple Life History Stages." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7624.
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Oil spills in the marine environment can threaten vulnerable ecosystems that support ecologically and economically significant organisms, such as the eastern oyster (Crassostrea virginica), in coastal habitats. The use of chemical dispersant (Corexit 9500) was applied as a cleanup effort in response to the Deepwater Horizon blowout to minimize crude oil slicks, but also resulted in increased concentrations of polycyclic aromatic hydrocarbons in the water column. The effects of increased soluble fractions of crude oil and dispersant components may be harmful to marine organisms. This study aimed to investigate possible sublethal impacts to the eastern oyster at multiple life history stages in order to understand potential implications on performance at an organismal, population, and ecosystem levels. Specifically, this study addressed 1) veliger swimming, 2) pediveliger settlement rates, 3) pollutant induced larval inactivity and 4) adult clearance rates after acute exposures to relevant concentrations (10 – 100 µL L-1) of water accommodated fractions of crude oil (WAF) and with a combination of chemical dispersant (CEWAF). No significant differences were observed in any tested swimming kinematics between controls and WAF or CEWAF treatments after 24 hour exposures for early staged veligers at concentrations up to 100 µL L-1 WAF and CEWAF. However, settlements rates of competent pediveligers were significant decreased compared to control (52.1 % s.d. 1.66) rates at concentrations of 50 µL L-1 WAF (30.9% s.d. 6.16) and 10 (41.2 % s.d. 0.857) and 50 (22.0% s.d. 1.23) µL L-1 CEWAF. Later staged larvae also showed increased vulnerability to oil pollution given that a higher percentage of organisms were inactive (48.3% s.d. 4.80) compared to early staged larvae (12.7% s.d. 7.68 ) after initial exposure at 50 µL L-1 CEWAF. Based on this result, we assumed effects of oil pollution were not manifested until the later larval life history stage evident by metamorphosis failure during the complex settlement transformation that results in reduced spat and eventually reduced adult oysters.
Adult oysters were also exposed to increasing concentrations of WAF and CEWAF for 24 hours and feeding experiments were conducted in both clean seawater and the same oiled seawater conditions as their initial exposure. Oysters fed in oiled seawater had decreased clearance rates, but oysters fed in clean water had increased clearance rates, suggesting feeding efficiency can be returned to control rates when moved to the presence of clean water. However, our long term study conducted in clean seawater suggested of the oysters exposed to crude oil only (9.31 L h-1 g-1 s.d. 2.04) are able to return to clearance rates comparable to controls (7.69 L h-1 g-1 s.d. 1.89) after the 33 day time period but oysters exposed to crude oil with a combination of chemical dispersant (2.12 L h-1 g-1 s.d. 1.08) were not. Decreased feeding efficiency can have negative impacts on water quality in estuarine ecosystems that support productive habitats. Understanding the impacts of crude oil, and crude oil with a combination of chemical dispersant on ecologically significant organisms can aid in future oil spill response decisions in order to minimize environmental impacts.
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Ambu, Zaira. "Impact of Ocean Acidification on respiration and regenerative capabilities of Amphiura filiformis and on Ostrea edulis larvae stages." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/2113/.
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Lara, Monica R. "Sensory development in settlement-stage larvae of Caribbean labrids and scarids: A comparative study with implications for ecomorphology and life history strategies." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539616729.
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The sensory capabilities of settlement-stage fishes are unknown but this information is necessary to studies of larval settlement and recruitment. The morphology of the cephalic lateral line, eye and external olfactory organ of thirteen species of settlement-stage Caribbean labroids was described. Scanning electron images of the cephalic lateral line neuromasts, lateral line canals and olfactory epithelia and histological studies of the retinae and morphological measurements of visual acuity were used to assess the level of sensory development attained at settlement. The sensory capabilities of settlement-stage fishes are discussed in relation to the possible cues settlement-stage fishes may be using to locate a reef and microhabitat within the reef system. In addition sensory development is discussed in relation to interspecific variation in settlement behavior, settlement-site selection, possible evolutionary life history strategies and morphological constraints on sensory development and settlement. development and settlement.
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Noble, Thomas H. "Effects of nitric and sulfuric-nitric acid solutions on mortality and development of aedes triseriatus mosquito larvae and pupae." Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/452402.
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An acid rain simulation was created under laboratory conditions to study the effects of mortality rates and developmental time of Aedes triseriatus (Say) mosquito larvae. Two hundred-forty instar 1 mosquitoes were placed into separate 120 ml glass jars containing rain water adjusted to pH 2, 3, 4, 5, 6, and 7 with a nitric acid solution. A second part of the experiment was set up like the first except a 70 percent to 30 percent sulfuric-nitric acid solution was used to adjust pH levels. Mortality and developmental time was observed until the insects reached maturity or died.No significant differences at the .05 level in mortality rates were observed between larvae raised in nitric acid solution as compared to sulfuric acid solution. However, exposures to 70 to 30% sulfuric-nitric solution resulted in a significantly (0.05) higher mortality at pH levels 4, 5, and 6 than the sulfuric acid or nitric acid exposures.Developmental time did not vary more the 0.5 days between the sulfuric acid exposure group and the nitric acid group except at pH 4.Ball State UniversityMuncie, IN 47306
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Gravil, Helen Ruth. "Studies on the biology and ecology of the free swimming larval stages of Lepeophtheirus Salmonis (Kroyer, 1838) and Caligus Elongatus Nordmann, 1832 (Copepoda: Caligidae)." Thesis, University of Stirling, 1996. http://hdl.handle.net/1893/2380.
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The study investigated biological and ecological parameters controlling and influencing the production and distribution of the free-swimming larval stages of Lepeophtheirus salmonis (Kroyer, 1838), and to a lesser extent Caligus elongatus Nordmann 1832, in the natural environment The reproductive output of L. salmonis was influenced by seasonal effects. The number of eggs produced per brood showed an inverse relationship with increasing temperature. The number of eggs per brood was also influenced by adult female body size (cephalothorax length), which in itself exhibited an inverse relationship with increasing temperature. Photoperiod had no significant effect upon the number of eggs produced or on adult female size. Mean egg size of L. salmonis varied significantly over the year; larger eggs were produced during the summer months and smaller eggs over the winter. However, factors controlling the size of the eggs were not elucidated. The proportion of viable eggs per L. salmonis ovisac remained constant throughout the year. Large variations in egg number per egg string were found in both L. salmonis and C elongatus populations sampled at one point in time. These were attributed in part to phenotypic variation in adult female size and also the number of broods individual females had produced. Egg viability was not correlated with brood size, but mean egg size was related to the number of eggs per brood. Experimental studies indicated that hatching and development of L. salmonis was highly variable. The percentage of eggs hatched and the time period over which hatching occurred varied markedly, even when held under constant and optimal environmental conditions. Temperature did not affect hatching success or viability of the nauplius I stage, although at higher temperatures the period over which hatching occurred was reduced. Low and medium salinities caused a significant decrease in both hatching success and nauplius viability. Photoperiod had no effect on initiation of hatching. Hatching occurred in a manner similar to that observed in free-living copepods. The nauplii were enclosed by two egg membranes, the outer one bursting within the ovisac, the inner one after the ovisac membrane has split. Swelling of the egg and its subsequent hatching was attributed to osmotic effects, with water being taken up from the external environment. Development was also highly dependent upon both temperature and salinity. At 5'C, nauplius 11 stages failed to enter the moult to the copepodid stage. At 7.5'C, although moulting was initiated, in a large proportion of cases it was not successfully completed. At I O'C, development to the copepodid stage was successful. Nauplii only developed successfully to the copepodid stage at salinities of 25%o or greater. Copepodids raised under optimal conditions then exposed to a range of salinities had a greater salinity tolerance than nauplii. Biochemical analysis of the eggs of L. salmonis revealed that lipids constituted a large proportion of their dry weight. Naupliar stages contained a discrete area containing lipid which decreased in size over time, suggesting that the free-swimming larval stages utilised this as an energy reserve. Rate of depletion was faster in nauplii held at higher temperatures. Longevity, activity and infectivity of the infective stage decreased with age. However, both spontaneous and stimulus dependent activity ceased many hours before death and both activity and longevity were affected by temperature. Infectivity of I day old L. salmonis copepodids was higher than 7 day old larvae, and was considered to be related to the size of the energy reserves. The settlement and distribution pattern of copepodids did not change with age of copepodid, the majority being recorded from the fins. All three L. salmonis free-swimming larval stages demonstrated a "hop and sink" swimming pattern. The velocity and duration of both passive sinking and active swimming was recorded for both nauplii and copepodids. Although greater periods of time were spent passively sinking, the speeds obtained during both upward spontaneous and stimulated swimming meant that a net upward movement of larvae in the water column occurred. At higher temperatures spontaneous swimming activity increased, whilst low salinities caused a cessation of such ability. L. salmonis larvae were positively phototactic and negatively geotactic. As well as their positive responses to light intensity, the nauplius 11 and copepodid stages reacted positively to blue-green spectral wavelengths. Moulting times were relatively short, although the larvae were not able to swim during such periods. No relationship was found between the level of lipid reserves and the overall buoyancy of the larvae. Naupliar stages of both L. salmonis and C. elongalus were obtained from the water column as a result of a plankton sampling programme at a commercial Atlantic salmon farm. No copepodid stages of either species were found. There was no difference in the vertical distribution of the two L. salmonis naupliar stages. Live larvae tended to aggregate between 0 and 5m in depth, with no diurnal vertical migration. Dead nauplii, and those with low lipid reserves, were found deeper in the water column. Naupliar stages, and in particular the first larval stage, were concentrated in number within cages indicating that the cages have a retentive characteristic. A novel control method in the form of a commercially available light lure was tested. Though increasing the numbers of free-living copepods captured, it had no effect on the numbers of L. salmonis naupliar or copepodid stages obtained in plankton samples. The present study has therefore provided valuable data concerning the biology and ecology of the free-swimming larval stages of sea lice, in what was a comparatively poorly understood area.
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Wisch, Lucas Nataniel. "FLUTUAÇÃO POPULACIONAL DOS PRINCIPAIS NOCTUÍDEOS E DISTRIBUIÇÃO VERTICAL DE OVOS E LARVAS NA CULTURA DA SOJA." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2011. http://tede2.uepg.br/jspui/handle/prefix/2215.
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Soybean is one of the main oleaginous crop produced in Brazil. Studies on populational dynamic and immature stage vertical distribution in soybean canopy are very important to improve technology application and control timing. We studied population dynamics and vertical distribution of eggs and larvae of the velvetbean caterpillar, Anticarsia gemmatalis and two Plusiinae species, during the cycle of two soybean cultivars of different growth habits in three sowing dates. Experiments were conducted on Coodetec 206 and BMX Potência RR cultivars during the 2010/2011 growing season in Ponta Grossa, Paraná state. Samples were collected through the crop cycle. Eggs and caterpillars from each third of the plant (bottom, middle and upper) and on different plant structures (main stem, branches, pods and adaxial or abaxial surfaces of leaves) were quantified. Data were analyzed using descriptive statistics and nonparametric Kruskal-Wallis analysis. Plusiinae species occurred simultaneously with A. gemmatalis, which was the predominant species. Highest densities of eggs and larvae of A. gemmatalis were recorded during the second half of January and February. In February we observed the highest densities of Plusiinae. Through the late sowing season we recorded the highest densities of immature stages of Noctuidae. The highest eggs densities for A. gemmatalis and Plusiinae occurred in the middle third (44.03% and 45.99%, respectively) of the canopy followed by the lower (31.96% and 34.18%) and upper portion (24.01% e 19.83%). Small larvae of A. gemmatalis were found mainly in middle (44.08%) and lower third of the plant (36.97%), while medium larvae occurred in higher density in the middle (42.86%) and upper (41.90%) stratum. Meanwhile, most of the large larvae are found in the upper portion of the canopy (63.41%). Highest densities of small, medium and large Plusiinae larvae, we found in middle (43.37%, 44.63% e 44.83%, respectively) and lower (49.46%, 31.40% e 31.03%) third of the canopy. Eggs and caterpillars were found mainly on the abaxial surface of leaflets.
A soja é uma das principais oleaginosas cultivadas no Brasil. Os estudos sobre a ocorrência dos estádios imaturos de Noctuídeos e sua distribuição espacial no perfil da planta são de grande importância para definir o momento de controle e aprimorar a tecnologia de aplicação. O objetivo deste trabalho foi avaliar a flutuação populacional e a distribuição vertical de ovos e larvas dos principais Noctuídeos, Anticarsia gemmatalis e Plusiinae, durante o ciclo de duas cultivares de soja de diferentes hábitos de crescimento em três épocas de semeadura. Os experimentos foram conduzidos durante a safra 2010/2011 no município de Ponta Grossa – PR, em três épocas diferentes de semeadura das cultivares Coodetec 206 e BMX Potência RR. As amostragens foram realizadas durante todo o ciclo da cultura em diferentes alturas da planta (terço superior, médio e inferior) e em diferentes estruturas da planta (haste principal, ramos, vagens e face adaxial ou abaxial das folhas). Os dados foram analisados através da estatística descritiva e do teste não-paramétrico de Kruskal-Wallis. As espécies de Plusiinae ocorreram simultaneamente a A. gemmatalis, a qual foi a espécie predominante. As maiores densidades de ovos e lagartas de A. gemmatalis foram registradas na segunda quinzena de janeiro e durante o mês de fevereiro, mês em que se observou maior densidade de Plusiinae. As semeaduras mais tardias apresentaram as maiores densidades de estádios imaturos de Noctuídeos. A maior oviposição, tanto para A. gemmatalis quanto a Plusiinae ocorreu no terço médio (44,03% e 45,99%, respectivamente) seguido pelo inferior (31,96% e 34,18%) e superior (24,01% e 19,83%). As lagartas pequenas de A. gemmatalis foram encontradas principalmente nos terços médio (44,08%) e inferior (36,97%), enquanto as lagartas médias ocorreram em maior densidade nos estratos médio (42,86%) e superior (41,90%) e os indivíduos grandes, na região apical (63,41%) do dossel. A maior densidade de lagartas de Plusiinae pequenas, médias e grandes foi observada no terço médio (43,37%, 44,63% e 44,83%, respectivamente) e inferior (49,46%, 31,40% e 31,03%). Os ovos e as lagartas dos Noctuídeos foram encontrados, principalmente, na face abaxial dos folíolos.
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Chotipuntu, Piyapong, and n/a. "Salinity sensitivity in early life stages of an Australian freshwater fish, Murray cod (Maccullochella peelii peelii Mitchell 1838)." University of Canberra. Resource, Environmental & Heritage Sciences, 2003. http://erl.canberra.edu.au./public/adt-AUC20060331.115030.
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The Murray cod (Maccullochella peelii peelii Mitchell 1838) is Australia�s largest freshwater fish. Once highly abundant in the Murray-Darling river system, populations have drastically declined in recent decades. Many causes for this decline have been proposed, including over-fishing, habitat loss and altered river flow regimes. This study hypothesised that elevated salinities have led to selective mortality in some developmental stages, which have in turn depleted stock recruitment and adult populations. The objectives of this study were to determine the optimal, threshold, upper sublethal and lethal salinities for development of eggs, yolk-sac larvae, fry and fingerlings of M. peelii peelii. Investigation the impact of salinity on fertilisation utilised gametes of trout cod (M. macquariensis, Cuvier 1829) instead of M. peelii peelii. Studies were carried out in a controlled laboratory environment using test media prepared from commercial sea salt. The results showed that the eggs of the trout cod hatched only when fertilised and incubated in freshwater, and only larvae hatched in freshwater survived through the yolk absorption period of 12 days. Yolk utilisation efficiencies were not significantly different among the salinities of 0-0.30 g/L. There was no effect of pre- or post- fertilising processes on the salinity tolerances of yolk-sac larvae. No larvae survived at salinities higher than 0.30 g/L during the yolk utilisation period. Lethal salinity concentration in Trout cod and Murray cod larvae was exposure time dependent. The 1 day LC50 of the larvae was 1.97 and 2.33 g/L respectively, compared with the 12 day LC50 values of 0.50 and 0.35 g/L respectively. The threshold (no effect level) salinities of larvae of Trout cod and Murray cod were 0.46 and 0.34 g/L respectively at 12 days exposure. The salinity sensitivities of fry of Murray cod were moderated by increasing pH between pH 6.2 and 8.8, and stimulated by increasing temperatures from 15 to 30°C. The optimal salinity was only slightly affected by temperature. The threshold and upper sublethal salinities varied slightly depending on feeding regime. The salinity sensitivities of fingerlings of Murray cod
were: LC50 = 13.7 g/L; optimal salinity from 4.6 to 5.0 g/L ; threshold salinity from 5.9 to 7.4 g/L, and upper sub-lethal salinity from 9.2 to 9.9 g/L � with the range in all cases affected by acclimation period salinity. The blood osmolality at LC50 of the fingerlings was 444 mOsmol/kgH2O or equivalent to 14.2 g/L, and the dehydration rate was 4.8%. The osmolality increased significantly in salinities higher than 9.0 and 6.0 g/L when fish were exposed for a period of 1 day and 41 days respectively. The oxygen consumption increased significantly in salinities higher than 8.0 g/L. Distortion of the notochord and corrosive skin syndrome were major symptoms describing sub-lethal effects found in the embryos, and fry and fingerlings of Murray cod respectively. Noting the risks of extrapolating directly from laboratory to field conditions, it is predicted that when salinity in natural habitats increases above 0.34 g/L a significant impact on Murray cod recruitment will result.
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Malarky, Lacey. "Faunal Composition and Distribution of Pelagic Larval and Juvenile Flatfishes (Teleostei: Pleuronectiformes) in the Northern Gulf of Mexico: Connectivity Between Coastal and Oceanic Epipelagic Ecosystems." NSUWorks, 2015. http://nsuworks.nova.edu/occ_stuetd/397.
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Pleuronectiformes (flatfishes) occur throughout the global oceans, and have high ecological and commercial importance in some areas. Though much is known regarding life history, abundance, and distribution for the benthic adult stage of flatfish species, much less is known about the pelagic larval phases of flatfishes in the open ocean. Taxonomic uncertainty and limited sampling in the oceanic Gulf of Mexico contribute to data gaps with respect to the distribution of early life history stage of flatfishes in this region. Knowledge of the faunal composition, abundance and distribution of larval flatfishes, such as members of Bothus, which have extended pelagic phases, is important for modeling their population dynamics as well as for understanding the importance of connectivity between neritic and oceanic ecosystems in their life histories. Pleuronectiform specimens utilized in this study were collected in the northern offshore Gulf of Mexico during several cruises conducted throughout 2010-2011 as part of the NOAA Natural Resource Damage Assessment (NRDA) after the Deepwater Horizon Oil Spill (DWHOS). The Offshore Nekton Sampling and Analysis program (ONSAP) was established to determine composition, abundance and distribution of deep-water invertebrates and fishes in Gulf of Mexico waters that were potentially affected by the DWHOS. Results of the first large-scale discrete-depth distributional analysis of fishes in this region revealed that flatfishes were an intrinsic component of the oceanic ichthyofauna of these waters. A total of 2365 flatfish specimens were collected in offshore waters, representing four families and 11 of the 18 genera that occur in the Gulf of Mexico. Species composition was dominated by members of the genus Bothus, which had a high frequency of occurrence in the epipelagic zone throughout the year. Citharichthys spilopterus and Trichopsetta ventralis were the second- and third-most abundant and frequently occurring taxa, respectively. Detailed spatial analyses of taxa in the epipelagic zone revealed that larvae of Citharichthys spilopterus were only collected in winter and occurred most frequently near the continental shelf break, while early life stages of Bothus spp. were more abundant at the northern convergence flow of a large anticyclonic Loop Current eddy during spring and summer.
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Blenzar, Abdelafi. "Effets d'un régulateur de croissance, le fénoxycarbe, sur le développement des larves du dernier stade de Psylla pyri (L.)." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37603071m.
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Vagner, Marie. "Orientation des processus métaboliques du bar européen (Dicentrarchus labrax) par un conditionnement nutritionnel au stade larvaire." Brest, 2008. http://www.theses.fr/2008BRES2009.
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Le but était de voir s’il est possible de stimuler les capacités de désaturation des acides gras pour la synthèse d’HUFA n-3 des juvéniles de bar par un conditionnement précoce. Lors d’une expérience 1 (F1), quatre groupes de larves ont reçu deux régimes de J6 à J45: LH (0,8% EPA+DHA) et HH (2,2%) à 16 ou 22°C. Après une période intermédiaire (2,7%, 19°C), la capacité des juvéniles à s’adapter à un régime carencé (0,5%) à été testée pendant 60 jours (19°C). L’expérience 2 (E2) avait pour but d’amplifier la réponse obtenue (une seul température d’élevage (19°C) et une gamme plus étendue de teneur en HUFA n-3 dans quatre régimes larvaires: XH (3,7%), HH (1,7%), LH (0,7%) et XLH (0,5%)). Après une période intermédiaire (2,7%, 19°C), les juvéniles ont reçu un régime à 0,35% pendant 35 jours. Les deux phases larvaires ont montré que les régimes carencés (0,8, 0,7 et 0,5%) stimulaient la transcription du gène de la delta-6 désaturase (∆6D, responsable de la première étape de synthèse des HUFA n-3) à J45. Mais une déficience en DHA dans les phospholipides (PL) et des retards de croissance ont été observés chez ces individus. Le conditionnement larvaire n’a pas affecté les performances de croissance des juvéniles mais E1 a montré une augmentation du niveau d’ARN de la (∆6D transitoire et une teneur en DHA des PL supérieure chez les juvéniles pré-conditionnés avec un régime carencé. F2 a mis en évidence une augmentation du niveau d’ARN tout au long de l’expérience mais une teneur en DHA similaire dans les PL. Il est possible de stimuler les capacités de désaturation des acides gras pour la synthèse d’HUFA n-3 des juvéniles de bar par un conditionnement précoceThe aim was to know if it is possible to apply a metabolic programming using nutritional conditioning during early larval stages to stimulate the fatty acid (FA) desaturation pathways of n-3 HUFA synthesis in marine fish. For the experience 1 (E1), four replicated groups of larvae were fed a diet with a Iow (LH) or high (HH) HUFA content from day 6 post-hatching to d-45 at 16 or 22°C: 0. 8 and 22% FPA÷DHA. After an intermediate period (19°C, 2. 7%), the capacity of juveniles to adapt to a HUFA-deprived diet (0. 5%) was tested during 60 days (19°C)- For the experience 2 (F2), four replicated groups of sea bass larvae were fed XH (3. 7% EPA+DHA), HH (1. 7%), LH (0. 7%) or XLH (0. 5%) diets from d-6 to d-45 at 19°C. After a period feeding a commercial diet (2. 7%, 19°C), the capacity of ail groups to adapt to an n-3 HUFA-Restricted diet (0. 3%) was tested for 35 days. The two larval periods indicated a positive modulation of the delta-6 desaturase (∆6D, rate-limiting enzyme responsible of the first step of the FA desaturation pathways for the n-3 HUFA synthesis) gene transcription by low dietary n-3 HUFA levels in larvae fed a low dietary HUFA n-3 content (0,8, 0,7 et 0. 5% EPA+DHA) than in others. Buta deficiency in DHA in phospholipides (PL) and a ower growth rate were observed, No significant effect of larval nutritional conditioning was observed in juveniles, but Fi showed a transient increase in mRNA level and an increase in DHA content in PL. F2 showed a persistent mRNA increase in pre-conditioned flsh, but similar DHA content in PL. T was possible to influence fatty acid desaturation pathways for HUFA synthesis, using a nutritional conditioning during larval stage
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BLENZAR, ABDELALI. "Effets d'un regulateur de croissance, le fenoxycarbe, sur le developpement des larves du dernier stade de psylla pyri l. (homoptera : psyllidae)." Toulouse 3, 1987. http://www.theses.fr/1987TOU30065.
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Le fenoxycarbe ro. 13-5223 ethyl (2-( p- phenoxy) ethyl ) carbamate, un regulateur de croissance des insectes (igr) a ete teste pour le controle des larves du dernier stade du psylle du poirier (psylla piry l. ), a la suite d'une application topique de differentes doses. La dl50 a ete determinee. Le fenoxycarbe s'est revele tres efficace, un fort % (60-80%) des individus meurt dans les jours qui suivent le traitement avec une dose de 5 ou 50 ug/larve. Le traitement provoque une perturbation de l'ecdysis et induit la formation d'individus intermediaires entre une larve et un adulte.
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Vignier, Julien. "Evaluation of the toxicity of the Deepwater Horizon oil and associated dispersant on early life stages of the ecologically and economically important Eastern oyster, Crassostrea virginica." Thesis, Brest, 2015. http://www.theses.fr/2015BRES0004/document.
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L’explosion du forage et de la plate-forme pétrolière Deepwater Horizon (DWH) le 20 Avril 2010 a entrainé la plus importante catastrophe pétrolière de l’histoire des Etats-Unis, avec des quantités sans précédent de pétrole (779,000 T) et de gaz relâchées continuellement dans le Golfe du Mexique durant près de 3 mois. En retour et comme moyen de réponse, 8 million L de dispersant chimique (principalement Corexit 9500A®) furent utilisés pour disperser les nappes, dont 2.9 million L furent injectés directement à la tête du puits à 1500 m de profondeur. La marée noire coïncida avec la saison de ponte et de recrutement de l’huitre américaine Crassostrea virginica, une espèce à haute valeur écologique et commerciale dans le Golfe. En raison de ces caractéristiques biologiques (sédentaire, espèce filtreuse, répartition géographique, ponte et fécondation externe), les huitres ont été utilisées comme organisme modèle en écotoxicologie. Néanmoins, il existe très peu de données disponibles sur la toxicité du pétrole brute (HEWAF), du pétrole dispersé (CEWAF) ou du dispersant sur les jeunes stades de vie de C. virginica. L’objectif de ce travail de thèse fut 1) de déterminer les effets létaux et sublétaux d’expositions aigües et chroniques à du pétrole DWH et/ou du Corexit 9500A® sur différents stades de développement des jeunes huitres, 2) d’examiner les mécanismes de toxicité des HAP (dissouts ou particulaires) issus du pétrole et du dispersant sur des processus physiologiques sensibles, et 3) d’établir si les résultats obtenus en laboratoire correspondent aux valeurs recueillies sur le terrain lors du programme NRDA. Nos résultats ont démontré que le pétrole et/ou le dispersant pouvaient affecter la reproduction et le développement embryonnaire et larvaire de C. virginica, et que le pétrole dispersé et le dispersant induisaient en général le plus d’impact. En outre, des effets sublétaux tels que des inhibitions de croissance larvaire, de fixation ou de filtration furent observés à des niveaux d’HAP et de DOSS mesurés dans l’environnement. Ces résultats suggèrent que le pétrole et l’utilisation de dispersant, en particulier lors de la saison de ponte de l’huître, pourraient affecter son recrutement et impacter la ressource de façon délétère dans des régions touchées par une marée noire. Par ailleurs, des critères biologiques plus sensibles que la mortalité devraient être choisis et inclus dans une approche intégrative, afin d’estimer plus précisément l’impact environnemental des hydrocarbures et le devenir de ses constituantsThe explosion of the Deepwater Horizon (DWH) oil drilling rig on 20th April 2010 resulted in the largest oil-related environmental disaster in U.S history with an unprecedented amount of oil (779,000 t) and gas discharged continuously in the Gulf of Mexico, over a period of 3 months. As a response, 8 million L of chemical dispersants (mainly Corexit 9500A®) were applied on surface to dissipate the slicks, and injected directly at the well head (3 million L) at 1500 m depths. The oil spill coincided with the spawning and recruitment season of the ecologically and commercially important Eastern oyster, Crassostrea virginica. Due to its biological characteristics (sessile, filter-feeding, ubiquity, “free” spawner), oysters have been employed as a model species in ecotoxicology and for monitoring the environment. However, information on the toxicity of crude oil (HEWAF), dispersed oil (CEWAF) and dispersant alone (Corexit 9500A®) on early developmental stages of C. virginica are limited. The aim of this study was to i) determine the lethal and sublethal effects of acute and chronic exposure to surface-collected DWH oil and/or Corexit 9500A® on various life stages of oysters, ii) examine the mode of toxicity of oil-associated PAHs (dissolved or particulate) and dispersant on sensitive physiological processes, and iii) establish whether there is a relationship between results collected in the laboratory and field data collected during the NRDA sampling program. Our results indicated that oil and/or dispersant adversely affected reproduction and early development of C. virginica, with dispersed oil and dispersant having generally the highest impacts. Furthermore, sublethal effects such as inhibition of larval growth, settlement success or filtration rates were observed at environmentally realistic concentrations of tPAHs or DOSS. These results suggest that oil spills and the use of dispersant as a spill response, especially at the time of oyster spawning season, could affect oyster recruitment and ultimately oyster populations in affected regions. Besides, in order to assess more precisely the environmental impact of an oil spill and the fate of its constituents, meaningful endpoints other than lethality should be selected
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Silva, Bianca Carvalho da. "Avaliação da toxicidade de quatro solventes e um surfactante, e dos fenilpropanoides eugenol e (E)-cinamaldeído sobre larvas e pupas de Musca domestica Linnaeus, 1758 (Diptera: Muscidae)." Universidade Federal de Juiz de Fora (UFJF), 2016. https://repositorio.ufjf.br/jspui/handle/ufjf/4062.
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Musca domestica é um importante vetor mecânico de diversos patógenos para humanos e animais de criação, sendo essencial o estudo de novas alternativas de controle mais eficientes e seguras para este díptero. A busca por novas alternativas de inseticidas envolve experimentos que geralmente necessitam do uso de solventes que não interfiram nos resultados da substância testada. Assim, o presente estudo compreendeu duas etapas: investigar a sensibilidade de larvas e pupas de M. domestica aos solventes acetona, etanol, metanol e dimetilsulfóxido (DMSO) e ao surfactante Tween 80 em diferentes tempos de volatilização; e avaliar a toxicidade dos fenilpropanoides eugenol e (E)-cinamaldeído sobre os mesmo estágios deste díptero. Para ambos os experimentos utilizou-se o teste de contato, com 10 repetições (n=10) para cada solvente/surfactante e concentração das substâncias sobre cada estágio. No primeiro experimento foram testados acetona, etanol e metanol em pureza analítica e DMSO e Tween 80 na concentração de 5%. Os tempos avaliados foram zero, cinco, 10 e 15 minutos (23±2°C e 60±10% UR). Os resultados mostraram que o tempo de volatilização produz diferença significativa na mortalidade larval (ML) para os três primeiros solventes testados, e acetona mostrou-se semelhante ao controle após cinco minutos de volatilização (p>0,05). Metanol e etanol mostraram-se semelhantes ao controle após 15 minutos de volatilização (p>0,05). DMSO não apresentou ML significativa (p>0,05), no entanto apresentou percenbtual de mortalidade acumulada (PMA) superiores a 14% (p<0,05). Tween 80 não apresentou diferença na toxicidade sobre as larvas relacionada ao tempo. Para o teste com pupas somente etanol produziu diferença significativa entre os tempos de volatilização, enquanto acetona e metanol diferiram do controle em todos os tratamentos (p<0,05). DMSO e Tween 80 não diferiram significativamente do controle em nenhum tempo (p˃0,05). O surfactante Tween 80 foi o único que não apresentou toxicidade para ambos os estágios na concentração testada, porém acetona foi o solvente que volatilizou mais rapidamente, mostrando menor toxicidade entre aqueles testados em pureza analítica. Para o segundo experimento, foram utilizadas oito concentrações de cada substância para a determinação das concentrações letais (CL50 e CL90). Eugenol apresentou os menores valores de CL50 e CL90, para a eficácia do tratamento larval (ETL) (1,5 e 3,75 mg/mL, respectivamente) enquanto (E)-cinamaldeido apresentou os menores valores de CL50 e CL90 para a eficácia do tratamento pupal (ETP) (18,08 e 78,83 mg/mL, respectivamente). Ambas as substâncias apresentaram atividade larvicida a partir de 2,5 mg/mL e ETL de 100% a partir de 5 mg/mL. Para o tratamento pupal (E)-cinamaldeído diferiu do controle a partir da 13 concentração de 10mg/mL (p<0,05) e ambos os fenilpropanoides causaram má formação em adultos a partir de 10 mg/mL, e maior ETP na concentração de 30 mg/mL, sendo 67,2% para (E)-cinamaldeído e 32% para eugenol. Os produtos testados nesse estudo apresentaram elevado potencial larvicida, além de ambos apresentarem efeitos pupicida e causarem má formação nos adultros provenientes de pupas tratadas. Ainda, é possível sugerir a utilização conjunta de ambas substância para um controle mais eficiente, visto que (E)-cinamaldeído apresentou melhor atividade larvicida, enquanto eugenol teve melhor atividade pupicida. Desta forma, esses fenilpropanoides mostrando-se promissores para o uso no desenvolvimento de formulações mais seguras para a saúde e meio ambiente, sendo possível sua utilização em estratégias de Manejo Integrado de Pragas.
Musca domestica is an important mechanical vector of several pathogens to humans and domestic animals, being essential to study new alternatives to eficiente and safe control against this Diptera. The search for new insecticides alternative involves experiments that generally require the use of solvents that should not interfere in the results of the test substance. Thus, this study involved two stages: to investigate the sensitivity of M. domestica larvae and pupae to the solvents acetone, ethanol, methanol and dimethylsulfoxide (DMSO) and the surfactant Tween 80 at different times of volatilization; and evaluating toxicity of phenylpropanoid eugenol and (E)-cinnamaldehyde against the same stages of this Diptera. For both experiments were used the patch test with 10 repetitions (n=10) for each solvent/surfactant and concentration of substances against each stage. In the first experiment acetone, ethanol and methanol were tested in analytical purity while DMSO and Tween 80 at the concentration of 5%. The times evaluated were zero, five, 10 and 15 minutes (23±2°C and 60±10% RH). The results showed that the volatilization time produces significant difference in larval mortality (LM) for the first three solvents tested, and acetone was similar to the control after five minutes volatilization (p>0.05). Methanol and ethanol were similar to the control after 15 minutes of evaporation (p>0.05). DMSO showed no significant LM (p> 0.05), but its accumulated mortality percenbtual (AMP) was over 14% (p<0.05). Tween 80 showed no difference in toxicity againts larvae related to time. For the pupae test only ethanol produced significant difference between the evaporation time, while acetone and methanol differed from the control in all treatments (p<0.05). DMSO and Tween 80 did not differ significantly from control at any time (p>0.05). The surfactant Tween 80 was the only one that showed no toxicity for both stages at the concentration tested, however the solvent acetone was volatilized more quickly, showing lower toxicity among those tested in analytical purity. For the second experiment, we used eight concentrations of each substance for the determination of lethal doses (LC50 and LC90). Eugenol showed the lowest values of LC50 and LC90 for the effectiveness of larval treatment (ELT) (1.5 and 3.75 mg/mL, respectively) while (E)-cinnamaldehyde had the lowest values of LC50 and LC90 for effectiveness of pupal treatment (EPT) (18.08 and 78.83 mg/mL, respectively). Both substances exhibited larvicidal activity from 2.5 mg/mL and ELT of 100% from 5 mg/mL. For pupal treatment (E)cinnamaldehyde differed from the control from the concentration of 10mg/mL (p <0.05) and both phenylpropanoid caused malformation in adults from 10 mg/mL. The greater EPT was from concentration of 30 mg/mL, being 67.2% for (E)-cinnamaldehyde and 32% for eugenol. 15 The products tested in this study had high potential larvicide, and both present pupicida effects and cause malformation in adultros from treated pupae. Still, it is possible to suggest the combined use of both substance for more efficient control, as (E)-cinamaldeído showed better larvicidal activity, while eugenol had better pupicida activity. Thus, using these phenylpropanoids show promise in the development of safer formulations for health and the environment, and these could be used in Integrated Pest Management strategies.
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Chang, Zisong. "Das Dauerstadium als Präadaptation." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17095.
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Wir fanden konservierte molekulare Signaturen der Regulation durch Δ7-DA und Ascarosid bei Dauer- und infektiösen Larven. Danach wurde die hohe Konservierung durch unsere Analyse in Dauer- und Postdauer-Stadium zwischen den zwei nah verwandten freilebenden Arten C. elegans und C. briggsae identifiziert. Das heißt, dass die relative Veränderung auf mRNA- oder Protein- Ebene zwischen zwei Arten stark korreliert ist. Aber die relative Veränderung innerhalb derselben Art zeigt keine hochgradige Korrelation zwischen mRNA- und Protein-Ebene. Unsere Ergebnisse zeigen in C. elegans Dauerlarven die signifikante Reduzierung der RNA-Mengen in 20 Stoffwechselwegen. Im Gegensatz dazu speicherten Dauerlarven reichlich RNA-Mengen in GO Termen wie Ribosome und Aminoacyl-tRNA biosynthesis. Auf Protein-Ebene sind die Stoffwechselwege von Proteinsynthese und Proteinverarbeitung im endoplasmatischen Retikulum in Dauerlarven herunterreguliert und GO Terme wie Lysosome sind hochreguliert. Durch die Zeitreihenanalyse der Proteom-Remodellierung der molekularen Signaturen beim Austritt aus dem Dauer-Stadium fand wir, dass GO Terme wie metal ion binding signifikant herunterreguliert sind und der Proteinabbau hochreguliert ist. Unsere Ergebnisse vom pSILAC Experiment deuten an, dass die Proteine für Energieerzeugung und Chaperone/Proteinfaltung beim Daueraustritt schnell verbraucht sind und wieder hergestellt werden. Zum Schluss haben wir als Erste den popomR-Assay in C. elegans etabliert und ein Screening der vermeintlichen Proteinbindestellen auf poly-A-RNA durchgeführt, um in der Zukunft die konservierten Mechanismen der post-transkriptionellen Regulation durch RBPs im Dauer-Stadium zu analysieren.We found the conservation of molecular signatures by regulating with Δ7-DA and Ascarosid in dauer larvae and infective larvae. Then by our comparative analysis, the high degree of conservation between two closely related free-living species C. elegans and C. briggsae was identified in dauer and post-dauer stages. This means that the relative changes are strongly correlated on the mRNA or the protein level between two species. But the relative changes in the same species don’t show any strong correlation between the mRNA and the protein levels. Our results showed a significantly reduced amount of RNA in 20 metabolic pathways in C. elegans dauer larvae. In contrast, dauer larvae stored a large amount of RNA in GO terms such as ribosome and aminoacyl-tRNA biosynthesis. On the protein level, the metabolic pathways of protein synthesis and protein processing in endoplasmic reticulum were downregulated in dauer larvae and the term of lysosome was up-regulated. Due to time course analysis for proteome remodeling of molecular signatures during exit process from dauer stage, we found that GO terms such as metal ion binding were significantly downregulated during dauer exit and at the same time the protein degradation was up-regulated. Our results of pSILAC experiment suggest that the proteins for energy generation and chaperone/protein folding are quickly spent and rebuilded during dauer exit. Finally, we were the first to establish the popomR assay in C. elegans and performed a screening of the putative protein binding sites on poly-A RNA to analyze the conserved mechanisms of post-transcriptional regulation by RBPs in dauer larvae in the future.
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Hempel, Esther. "Controlling Factors Of Life Cycle And Distribution Of Chironomid Key Species In The Mesotrophic Saidenbach Reservoir." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-72141.
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In den Jahren 2005 bis 2010 erfolgte im Rahmen der Erarbeitung der vorliegenden Dissertationsschrift eine ökologische Untersuchung der Chironomidenfauna in der Talsperre Saidenbach (Sachsen, Erzgebirge). Drei Arten mit hoher Abundanz konnten bei der umfassenden Artenanalyse im Jahr 2005 ermittelt werden: Procladius crassinervis, P. choreus und Chironomus anthracinus. Zusätzlich wurde die Art C. plumosus aufgrund ihrer engen Verwandtschaft zu C. anthracinus in die Untersuchung einbezogen. Die Arbeit ist auf vier Schwerpunkte fokussiert, wobei die Larven und Puppen der vier Arten analysiert wurden. (1) Die Erarbeitung einer zuverlässigen Methode zur Unterscheidung der Larven der beiden eng verwandten Procladius-Arten basierend auf morphologischen Kriterien (Imaginalscheiden-entwicklung, Kopfkapselgröße und Körperlänge) sowie die Tiefenverteilung der Puppen waren eine Vorbedingung für weiterführende Analysen des Lebenszyklus (LZ) dieser beiden Arten. (2) Die Untersuchung des LZ war der zweite Schwerpunkt. Der LZ wurde stark von abiotischen Faktoren wie Temperatur, Sauerstoff und Biovolumen des Phytoplanktons kontrolliert. (3) Die raum-zeitlichen Verteilungsmuster der vier Arten wurden zunächst bezüglich großräumiger Unterschiede über einen Tiefengradienten innerhalb eines Transektes analysiert. Hierbei zeigte sich bei allen vier Arten eine zeitliche Änderung im jeweiligen Hauptverbreitungsgebiet. Die jungen Larven von C. anthracinus, C. plumosus und P. choreus wanderten im Verlauf ihrer Entwicklung bis zur Verpuppung in flachere Bereiche, P. crassinervis wanderte in tiefere Bereiche. Die Analyse der Verteilungsunterschiede der Larven zwischen zwei verschieden stark eutrophierten Buchten ergab höhere Dichten der beiden Chironomus-Arten in der Bucht mit dem größeren Zulauf und der höheren Phytoplanktonkonzentration im Vergleich mit den anderen Arten. Eine Analyse des kleinräumigen Verteilungsmusters fokussierte auf der Frage, ob die Larven gleichmäßig verteilt oder aggregiert auftraten. Die Untersuchung des vertikalen Verteilungsmusters erforschte das Schwimmverhalten der Larven. (4) Der letzte Aspekt war eine experimentelle Untersuchung, die am Beispiel von C. anthracinus durchgeführt wurde mit dem Ziel, den Proximatfaktor für die beobachtete Wanderung der Larven zu ermitteln, der letztendlich die Temperatur war. Puppen bevorzugten im Experiment wärmere Temperaturen und junge Larven kühlere Temperaturen. Die fünfjährige Untersuchung der Chironomiden in der Talsperre Saidenbach beschreibt insgesamt die komplexe Verhaltensreaktion der Chironomiden, die einen wesentlichen Teil der benthischen Lebensgemeinschaft darstellen, bezüglich der Lebenszyklusmuster (Voltinismus, Verpuppung), der Abundanzänderungen (inner- und zwischenjährlich) sowie der groß- und kleinräumigen Verteilung unter der Einwirkung der wichtigsten UmweltfaktorenIn the context of the present dissertation an ecological study was performed about chironomids in Saidenbach Reservoir in the Saxony Ore Mountains, Germany during the five years from 2005 to 2010. A preliminary overall species analysis in 2005 showed that three species were most abundant: Procladius crassinervis, P. choreus and Chironomus anthracinus. Additionally, the species C. plumosus was examined because of its close relationship to C. anthracinus. The study is focussed on four subjects, whereby larvae and pupae of the four species were analysed. (1) The elaboration of a reliable method to distinguish the larvae of the two closely related species P. crassinervis and P. choreus on the basis of morphological criteria (imaginal disc development, larval head capsule size and body length) as well as the depth distribution of their pupae was a precondition to the profound analysis of their life cycles. (2) The investigation of the life cycle pattern of the four species was the second focus. The life cycle of the four species was found to be strongly influenced by abiotic conditions such as temperature, oxygen and biovolume of the phytoplankton. (3) The spatial and temporal distribution pattern of the four species was analysed in view of large scale differences over a depth gradient in one transect. Here, in all four species a shift in the mainly settled lake bottom area occurred. The young larvae of C. anthracinus, C. plumosus and P. choreus migrated during maturing and pupation towards shallower areas; P. crassinervis migrated to deeper areas. The distribution differences between two different bays showed that the two Chironomus species had higher densities in the bay with the higher inflow which resulted in a higher phytoplankton standing stock compared to the other species. A small scale distribution pattern analysis focussed on finding out whether the larvae were aggregated or randomly distributed. The vertical distribution analysis examined the swimming behaviour of the larvae. (4) The last aspect was an experimental setup exemplarily driven with C. anthracinus which showed that the migration was stimulated by the proximate factor temperature as pupae preferred warmer temperatures and young larvae colder temperatures. Altogether, the five year study about chironomids in Saidenbach Reservoir pointed out the complex reaction in the behaviour of an important part of the benthic community concerning the life cycle pattern (voltinism, pupation pattern), the changing in abundances (inter-annual and intra-annual) and the large scale and small scale distribution pattern under the rule of the most important environmental factors
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Laabs, Eva-Maria Wiebke [Verfasser]. "Transcriptome analysis of preadult hypobiotic and non-hypobiotic L5 stages as well as in vitro studies on the sexual maturation of preadult larvae of the bovine lungworm Dictyocaulus viviparus / Eva-Maria Wiebke Laabs." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2011. http://d-nb.info/1018968520/34.
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Boukadida, Ammar Khouloud. "Etude des réponses de la moule Mytilus spp exposée à des stress métallique et thermique durant les stades embryo-larvaires." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0571/document.
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Les écosystèmes marins côtiers sont soumis à des pressions anthropiques et naturelles qui placent les organismes aquatiques dans des situations de multi-stress.Ce travail doctoral avait pour objectif d’évaluer l’impact et de mieux comprendre les mécanismes d’adaptation des premiers stades de vie de moule exposés à deux facteurs environnementaux majeurs : la pollution métallique et l’accroissement des températures des eaux marines côtières. Les effets induits par l’exposition à deux polluants métalliques modèles (Cu et Ag) et à un stress thermique modéré seuls ou en combinaison ont été évalués sur les stades précoces de développement de deux espèces de moule : Mytilus galloprovincialis et Mytilus edulis ainsi que leurs hybrides. Nos résultats montrent une augmentation significative du pourcentage de larves D ma lformées avec l’augmentation de la température. Par ailleurs, l’Ag apparaît significativement plus toxique que le Cu pour les larves. De plus,la toxicité des métaux s’accroit avec l’augmentation de la température. La coexposition aux métaux et à une température modérée augmente les activités enzymatiques antioxydantes de la catalase (CAT), de la superoxyde dismutase (SOD)et de la glutathion-S-transférase (GST) et accroît le contenu cellulaire en métallothionéines et la peroxydation lipidique. A une température plus élevée de 22 °C,une diminution significative des activités des enzymes antioxydantes est observée.Les dommages à l’ADN chez les larves-D de moule M. gallo provincialis ont été évalués à l’aide du test des comètes avec et sans traitement par la Formamidopyrimidine ADN glycosylase. L’exposition aux métaux et/ou à la température aaugmenté de manière significative les lésions de l’ADN sur les larves de moule,avec un effet plus accentué sur les dommages oxydatifs. Il a été montré également que le Cu et l’Ag sont accumulés différentiellement dans les larves en fonction de la température d’exposition. L’étude de l’expression par RT-qPCR de 18 gènes impliqués dans les défenses antioxydantes, la réparation de l’ADN, l’apoptose,la protéolyse, la transcription, les réponses au stress thermique et la détoxification métallique a été conduite chez les larves-D de moule M. galloprovincialis.En cas d’un stress thermique modéré, une tendance à la surexpression des gènes impliqués dans les défenses cellulaires est observée. Toutefois, en cas d’une coexposition métallique et thermique, les voies d’apoptose et d’altération cellulaires sont activées.Un plugin et une macro ont été développés pour le logiciel ImageJ afin d’évaluer et de caractériser le comportement de nage des larves D de M. galloprovincialis.Une augmentation significative de la vitesse maximale des larves-Davec l’augmentation de la température est observée sans que la vitesse moyenne soit affectée. En revanche, l’exposition au Cu et à l’Ag à 22 °C augmente significativement les vitesses moyenne et maximale des larves. En condition contrôle à18 °C, les larves suivent principalement des trajectoires rectilignes (88 %). Avec l’augmentation de la température et/ou l’exposition aux métaux, les trajectoires circulaires augmentent considérablement au détriment des trajectoires rectilignes.Ces modifications de comportement pourraient être liées d’une part à l’induction de malformations mais aussi à la modulation de l’activité neuronale. Ainsi, une augmentation significative de l’activité acétylcholine estérase (AChE) des larves a été observée suite à l’exposition à un gradient de températures et/ou aux métaux.Des larves D viables et normalement développées ont été obtenues par hybridation de M. galloprovincialis et M. edulis. Les larves de M. edulis apparaissent plus sensibles à la température que les larves de M. galloprovincialis. Aucune différence significative de sensibilité n’a été observée entre les moules hybrides et pures quelque soit le métal testé. (...)Coastal marine ecosystems are subject to anthropogenic and natural pressures that place aquatic organisms in multi-stress situations. The aim of this doctoral work was to assess the impact and better understand the adaptation mechanisms of mussel early life stages exposed to two major environmental factors : metallic pollution and increasing temperatures in coastal marine waters. The effects induced by exposure to two model metal pollutants (Cu and Ag) and moderatethermal stress alone or in combination were evaluated on the early life stages of development of two mussel species : Mytilus galloprovincialis and Mytilus edulisas well as their hybrids. Our results show a significant increase in the percentageof malformed D-larvae with increasing temperature. Moreover, Ag is significantly more toxic than Cu for larvae. In addition, the toxicity of metals increases with increasing temperature. Co-exposure to metals and a moderate temperature increases the antioxidant activity of catalase (CAT), superoxide dismutase (SOD)and glutathione-S-transferase (GST), and increases cellular content of metallothioneinsand lipid peroxidation. At a higher temperature of 22 °C, a significant decrease in the activities of the antioxidant enzymes is observed. DNA damage in M. galloprovincialis larvae was evaluated using the comet assay with and without Formamidopyrimidine DNA glycosylase treatment. Co-exposure to metals and/ortemperature increase significantly increased DNA lesions on mussel larvae, witha more pronounced effect on oxidative damage. It has also been shown that Cuand Ag are accumulated differently in the larvae as a function of the exposure temperature. The study of the gene expression by RT-qPCR of 18 genes involvedin antioxidant defenses, DNA repair, apoptosis, proteolysis, transcription, thermal stress and metal detoxification was conducted in D-larvae of M. galloprovincialis.Under moderate thermal stress, a tendency of over expression of the cell defense pathways is observed. However, in the case of metallic and thermal co-expositions, the pathways of apoptosis and cellular alteration are rather induced. A pluginand macro were developed for the evaluation and characterization of behavior oflarvae of M. galloprovincialis. A significant increase in the maximum speed of D larvaewith increasing temperature is observed without affecting the mean velocity. In contrast, exposure to Cu and Ag at 22 °C significantly increases average and maximum larval speed. Under controlled conditions at 18 °C, larvae mainly follow rectilinear trajectories (88 %). With increasing temperature and/or exposure to metals, circular trajectories increase considerably at the expense of rectilinear trajectories. These changes in behavior may be related to the induction of malformations but also to the modulation of neuronal activity. Thus, a significant increase in the acetylcholinesterase (AChE) activity of the larvae is observed following exposure to a temperature gradient and/or metals. Viable and normally developed D-larvae were obtained by hybridization of M. galloprovincialis and M.edulis. Larvae of M. edulis are more sensitive to temperature than larvae of M. galloprovincialis.No significant sensitivity differences between species are observed whatever the metal used. Moreover, the hybrid larvae from female M. galloprovincialis are more tolerant to the increase of temperature compared to the hybrid larvae issues from rom female of M. edulis
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Kiselyova, Tatiana. "Systematics of Dermestidae (Insecta: Coleoptera) based on the larval stage." 2003. http://purl.galileo.usg.edu/uga%5Fetd/kiselyova%5Ftatiana%5Fg%5F200305%5Fphd.
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Thesis (Ph. D.)--University of Georgia, 2003.Directed by Joseph V. McHugh. Includes an article published in The coleopterists bulletin, and articles submitted to The coleopterists bulletin, and Annales zoologici. Includes bibliographical references.
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詹宗偉. "Taxonomic studies of the larval stage of Aeshnidae(Odonata) in Taiwan." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/83881845341361596870.
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