Dissertations / Theses: 'Echinoidea'

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Wangensteen, Fuentes Owen S. "Biology and phylogeography of the black sea urchin Arbacia lixula (Echinoidea: Arbacioida) / Biología y filogeografía del erizo de mar negro Arbacia lixula (Echinoidea: Arbacioida)." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/120483.

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The black sea urchin Arbacia lixula (Linnaeus, 1758) is one of the most abundant sea urchins in the Mediterranean. Despite its increasingly recognized ecological significance, including the ability to create and maintain barren zones of decreased diversity and productivity, it has been traditionally less studied than the Atlanto-Mediterranean edible sea urchin Paracentrotus lividus. This thesis is aimed at studying the factors affecting the phylogeography, trophic ecology and biology of the black sea urchin A. lixula in Mediterranean ecosystems, in order to assess its ecological role and its possible future impact in benthic communities. We studied the phylogeography, the trophic relationships, the reproductive cycle and the effects of temperature and ocean acidification on larval development of A. lixula. Our phylogeographical study, based in the mitochondrial marker COI, found evidences of a relatively recent (94 – 205 kya) colonization of the Mediterranean by A. lixula. Our trophic study, using stable isotopes and gut contents analyses, showed that A. lixula is an omnivore tending to carnivory, feeding mainly on sessile invertebrates. This results challenge the previous belief that A. lixula was an herbivorous grazer of encrusting coralline algae. The results of the reproductive cycle study, followed up during four consecutive years, showed that the reproductive timing of A. lixula is regulated by photoperiod, while temperature is a main modulator of its gonad development and thus of its reproductive output. The study of larval development in different conditions of temperature and pH showed that temperature increases accelerated the development and enhanced the larval survival rate, while acidification caused only slight effects in its survival, developmental rate and larval morphology. Considering all these new results about the past history and ecological characteristics of A. lixula, we conclude that this thermophilous species of tropical affinities is probably facing suboptimal conditions in northern Mediterranean. Its populations in this region may be promoted by global change, since the current warming trend would eventually enhance the processes which are limiting its populations. Thus, the negative impact of A. lixula on the Mediterranean coastal ecosystems may be increased in the future.
El erizo de mar negro Arbacia lixula (Linnaeus, 1758) es, en la actualidad, uno de los equinoideos más abundantes en el Mediterráneo. A pesar de que su importancia ecológica está siendo cada vez más documentada, incluyendo su capacidad para originar y mantener zonas de blanquizal, de diversidad y productividad disminuidas, A. lixula ha sido tradicionalmente menos estudiado que otras especies atlanto-mediterráneas, como el erizo de mar común, Paracentrotus lividus. Esta tesis tiene por objeto el estudio de los factores que afectan a la filogeografía, la ecología trófica y la biología de A. lixula en los ecosistemas mediterráneos, con el fin de investigar su papel ecológico y su potencial impacto futuro en las comunidades bentónicas. Se estudiaron la filogeografía, las relaciones tróficas, el ciclo reproductor y los efectos de la temperatura y de la acidificación del océano en el desarrollo larvario de A. lixula. Nuestro estudio filogeográfico, basado en el marcador mitocondrial COI, mostró evidencias de que A. lixula colonizó el Mediterráneo en tiempos relativamente recientes (hace entre 94,000 y 205,000 años). El estudio de ecología trófica, empleando análisis de isótopos estables y de contenidos digestivos, demostró que A. lixula tiene un comportamiento omnívoro con tendencia a la carnivoría, alimentándose, sobre todo, de invertebrados sésiles. Esto contradice las creencias previas que suponían que esta especie era un herbívoro que se alimentaba de algas coralináceas incrustantes. El estudio de la biología reproductiva de A. lixula, realizado a lo largo de cuatro años consecutivos, mostró que el curso temporal de su ciclo gonadal está regulado por el fotoperíodo, mientras que la temperatura es un importante modulador de su desarrollo gonadal y de su producción de gametos. El estudio del desarrollo larvario, utilizando diferentes condiciones de temperatura y pH, mostró que el aumento de temperatura produce una aceleración en el crecimiento y un aumento en la tasa de supervivencia larvaria, mientras que la acidificación causa sólo efectos menores en la tasa de supervivencia, la velocidad de desarrollo y la morfología larvaria. Considerando estos nuevos resultados sobre la historia evolutiva y las características ecológicas de A. lixula, podemos concluir que esta especie de afinidades tropicales se encuentra, probablemente, sometida en la actualidad a condiciones por debajo de las óptimas en el Mediterráneo septentrional. Sus poblaciones en esta región podrían verse favorecidas por el cambio global, ya que la tendencia al calentamiento actual posiblemente favorecerá, en el futuro, los procesos que están limitando sus poblaciones en la actualidad. Así, el impacto negativo de A. lixula en los ecosistemas costeros mediterráneos podría incrementarse en el futuro.

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Courville, Erwan. "Analyse intégrée de données fossiles et actuelles, morphologiques et moléculaires pour comprendre l’évolution écologique et biogéographique du genre Arbacia Gray, 1835 (Echinoidea) au cours du Cénozoïque." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. http://www.theses.fr/2024UBFCK076.

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Cette thèse examine le rôle des facteurs écologiques et historiques dans la distribution biogéographique du genre d’oursin Arbacia (Echinoidea, Arbacioida). Le projet est structuré en trois volets. D’abord, la révision taxonomique du genre, qui a révélé une diversité morphologique plus vaste que prévu, avec la découverte de sept nouvelles espèces fossiles. Ensuite, des analyses phylogénétiques, basées sur des marqueurs moléculaires, pour résoudre les relations de parenté entre espèces actuelles. Ces analyses ont montré une divergence ancienne entre les espèces atlantiques et pacifiques, bien avant la formation de l'isthme de Panama. Une phylogénie intégrée combinant des données morphologiques et moléculaires a permis d’intégrer les données actuelles et fossiles, soulignant une histoire évolutive complexe. Enfin, les analyses biogéographiques ont permis de montrer que les événements de dispersion ont joué un rôle prépondérant dans l’histoire évolutive du genre Arbacia, avec des événements récurrents de spéciation par dispersion depuis les régions tempérées vers les zones tropicales, notamment le long des côtes californiennes et dans les Caraïbes. Les événements de duplication sont également nombreux suggérant des phénomènes de spéciation sympatrique. La modélisation des niches écologiques des espèces actuelles d’Arbacia, ainsi que d’une espèce fossile, a permis de proposer des hypothèses quant aux rôles des facteurs écologiques dans l’évolution du genre. Contrairement au paradigme selon lequel les tropiques sont des centres d'origine pour la biodiversité marine, les résultats de la thèse montrent que le genre Arbacia s’est diversifié et dispersé principalement à partir des zones tempérées du Pacifique Nord-Est, avant de se disperser vers les régions tropicales
This PhD thesis examines the role of ecological and historical factors in the biogeographical distribution of the echinoid genus Arbacia (Echinoidea, Arbacioida). The project is structured into three parts. First, the taxonomic revision of the genus revealed a higher level of morphological diversity than expected, with the discovery of seven new fossil species. Then, phylogenetic analyses based on molecular markers were performed to resolve the relationships among extant species and showed an ancient divergence between Atlantic and Pacific species predating the formation of the Isthmus of Panama. An integrated phylogeny was constructed combining morphological and molecular data, with both extant and fossil species, highlighting a complex evolutionary history. Finally, biogeographical analyses were performed that showed that dispersal events have played a key role in Arbacia evolutionary history, with recurrent speciation events due to dispersal from temperate regions to tropical zones, especially along the Californian coasts and in the Caribbean. Several duplication events were also highlighted suggesting a role played by sympatric speciation. Ecological niche modeling of both extant and fossil species are clues to set hypotheses about the part played by ecological factors in the genus evolution. Contrary to a paradigm of the tropics as centers of origin for marine biodiversity, PhD results show that Arbacia likely diversified in the temperate Northeast Pacific then dispersed toward tropical regions

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Hétérier, Vincent. "Biodiversité et signification écologique des ectosymbiontes des Cidaridae antarctiques (Echinodermata : Echinoidea)." Dijon, 2007. http://www.theses.fr/2007DIJOS012.

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Les oursins cidaridés caractérisés par l’absence d’épithélium sur leurs piquants primaires, procurent une grande diversité de substrats pour les organismes sessiles, particulièrement en Antarctique. L’inventaire des espèces symbiotiques montre une dominance nette des spongiaires et des bryozoaires et que la diversité des ectosymbiotes fluctue en fonction des espèces hôtes et de la profondeur. Par contre, la distance entre les stations n’influence pas la structure et la composition des communautés symbiotiques. Une analyse morphologique des piquants a été réalisée afin de connaître l’influence de leur forme sur les communautés symbiotiques. Les résultats suggèrent que la colonisation symbiotique est directement liée aux paramètres dimensionnels des piquants (taille & spinosité). Les communautés symbiotiques diffèrent sensiblement de celles des tillites (roches environnantes). Contrairement aux symbiotes, les faunes portées par les tillites sont relativement semblables entre les stations
Cidaroid sea urchins provide a wide range of substrates for sessile organisms, particularly in Antarctic where the availability of hard substrate is a limiting resource. An inventory of Antarctic cidaroid ectosymbionts showed that 62% of ectosymbionts are bryozoans and sponges. Ectosymbiotic specific diversity varied with the host species and depth, but the distance between sampling sites did not affect community structure and composition. Two sets of parameters were defined to determine the influence of cidaroid spine shapes on symbiotic communities. Morphometric analyses showed the existence of a gradient between oral, ambital and apical spines. Symbiont colonization was directly related to dimensional parameters of the spines. Finally, symbiotic communities associated with cidaroids strongly differ from the tillites-associated ones. Taking cidaroid-associated communities into account is therefore necessary to get an exhaustive picture of the Antarctic benthic biodiversity

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Heterier, Vincent. "Biodiversité et signification écologique des ectosymbiontes des Cidaridae antarctiques (Echinodermata :Echinoidea)." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210644.

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Mac, Cord Fábio Sá. "Estratégia reprodutiva e gametogênese de Cassidulus mitis Krau, 1954 (Echinodermata : Echinoidea)." Universidade Federal do Rio de Janeiro, 2001. http://hdl.handle.net/11422/3504.

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A ordem Cassiduloida inclui todos os ouriços irregulares que apresentam petalóides, filódios e borrainas ( ou flósculo) (KIER, 1962). Eles possuem, ainda, espinhos curtos e um periprocto disposto posteriormente (MOOI, 1990a). Esta ordem chegou a ser representada por aproximadamente 800 espécies em 67 gêneros. Durante o Eoceno (50 milhões de anos atrás), 60% de todas as espécies de equinóides pertenciam a ordem Cassiduloida (KIER, 1962). Cassidulus mitis Krau é uma espécie endêmica do Rio de Janeiro. Para verificar seu ciclo reprodutivo foram feitas coletas mensais na Praia Vermelha de outubro de 1998 a abril de 2000. A razão sexual encontrada foi de 1:1 (x2= 1.48; a0.05=3.84; DF= l). A reprodução é contínua e não há sincronia entre os indivíduos. O índice gonadal dos machos foi superior ao das fêmeas (x2=18.33, a0.05=3.84). Os machos possuem cinco estágios de desenvolvimento gametogênico: Crescimento, Pré-maduro, Maduro, de Liberação e Estágio de liberação e crescimento concomitante. Os machos não apresentam os estágios de Recuperação e vazio que as fêmeas possuem. Já as fêmeas possuem seis estágios: Recuperação, Crescimento, Pré-maduro, Maduro, de Liberação e Vazio. Todavia, não apresentam o estágio de liberação e crescimento concomitante que ocorre nos machos. O diâmetro médio dos ovócitos foi de 382 μm (DP=49 μm). O número médio de juvenis por fêmea foi de 99.8 indivíduos (DP= l08.25; SE= 16.32). As gônadas anteriores são comumente menores que as posteriores e diferenças nos estágios gametogênicos foram encontradas entre elas. A primeira maturação ocorre em indivíduos a partir de 17mm de diâmetro. O peso úmido do intestino é aproximadamente duas ou três vezes maior que o peso úmido da carapaça. Isto significa que C. mitis utiliza seu intestino como um cinto de lastro para evitar seu deslocamento.
Cassidulus mitis Krau is an endemic species from Rio de Janeiro, Brazil. To verify its reproductive cycle, samples were taken from October 1998 to April 2000 at Vermelha Beach. Sex ratio of 1 (x2= 1.48; a0.05=3.84; DF= l) was found for C. mitis. Reproduction occurs overall the year. Gonadal index (GI) of males was greater than GI of females (x2= 18.33, a0.05=3.84). Reproduction is asynchronous. Males have five gametogenic stages: Early growth, Premature, Mature, Partially spawned and Early growth with partially spawned stage. There is no Spent or Recovery stage as in females. Females have six gametogenic stages: Recovery, Early growth, Premature, Mature, Partially spawned and Spent stage but there is no Early growth with partially spawned stage as in males. Mean diameter of oocytes was 382 μm ( DP=49 μm). Mean number of juveniles per female was 99.8 individuals (DP= 108.25; SE= l6.32). Anterior gonads are commonly smaller than posterior ones. Differences in gametogenic stages were found between anterior and posterior gonads. First sexual maturity occurs in individuals larger than 17 mm. Intestine wet weight is about two or three fold higher than test wet weight. It means that C. mitis uses its intestine as a weight belt to avoid displacement.

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Souto, Camila. "Sistemática da família Cassidulidae (Echinoidea: Cassiduloida) e considerações taxonômicas e paleobiogeográficas." reponame:Repositório Institucional da UFBA, 2013. http://www.repositorio.ufba.br/ri/handle/ri/12823.

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Os cassidulóides têm proporcionado grandes desafios aos taxonomistas que tentam classificá-los, provavelmente por se tratar de um grupo artificial. Estudos filogenéticos da ‘ordem’ resultaram em topologias com baixa resolução devido à falta de informação acerca de alguns táxons e sinais de exaustão de caracteres ao longo da evolução de suas famílias. Dentre elas, a família Cassiulidae é composta por cinco a seis gêneros e pouco se sabe sobre o relacionamento entre seus gêneros, visto que análises ao nível de ordem incluíram poucas espécies desta família. Neste trabalho foram realizadas análises cladísticas para propor uma hipótese de relações filogenéticas entre os gêneros da família Cassidulidae. A análise principal incluiu 16 cassidulídeos e 33 caracteres morfológicos. As análises seguintes tiveram como objetivo verificar a influência dos dados faltantes e da inclusão de táxons fósseis na topologia encontrada. Cada uma das três análises resultou em uma única árvore mais parcimoniosa, em geral, bem resolvida. As relações de parentesco foram: (Eurhodia relicta (demais Eurhodia) + ((Australanthus + Cassidulus malayanus) + (Paralampas (Cassidulus + Rhyncholampas)))). Tanto a quantidade de dados faltantes quanto a exclusão de espécies fósseis não afetaram negativamente a resolução da árvore. Os resultados obtidos indicaram a necessidade de estudar a taxonomia, principalmente, dos gêneros Eurhodia, Cassidulus e Rhyncholampas e a exclusão de Cassidulus malayanus e Eurhodia relicta dos seus respectivos gêneros. Possíveis ocorrências de processos heterocrônicos foram detectadas, a exemplo da evolução do gênero Rhyncholampas por peramorfose e do gênero Paralampas por pedomorfose. Os cassidulídeos provavelmente se originaram no Cretáceo Tardio e novidades não foram adicionadas à sua evolução. Como resultado, processos heterocrônicos devem ter desempenhado um papel importante na diversificação da família. Evidências de processos heterocrônicos obtidas a partir da análise atual foram discutidas. Finalmente, um cenário paleobiogeográfico dos cassidulídeos foi proposto, com origem Tetiana e dispersão inicial, seguida por expansão e vicariância.
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Cunningham, Adele. "The reproductive cycle of Lytechinus variegatus (Echinodermata: Echinoidea) from the Florida panhandle." Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2008d/cunningham.pdf.

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Thesis (Ph. D.)--University of Alabama at Birmingham, 2008.
Additional advisors: Andy Gannon, John Lawrence, James McClintock, Thane Wibbels. Description based on contents viewed May 29, 2008; title from title screen. Includes bibliographical references.

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Chiu, Sein-tuck, and 趙善德. "Aspects of the ecology of Anthocidaris crassispina (echinodermata: echinoidea) in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31230805.

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Madon-Senez, Céline. "Disparité morphologique et architecturale des schizasteridae incubants (Echinoidea, Spatangoïda) des régions australes." Dijon, 1998. http://www.theses.fr/1998DIJOS065.

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Cette thèse constitue une monographie détaillée de 27 espèces d'échinidés endémiques aux régions antarctique et subantarctique. Ces oursins sont repartis dans les genres incubants actuels Abatus, Amphipneustes, Tripylus et Brachysternaster (famille des Schizasteridae). Ils présentent un fort dimorphisme sexuel : les femelles ont développé des poches incubatrices dans lesquelles les juvéniles terminent leur développement. L'objectif majeur de cette thèse a consisté à inventorier la disparité morphologique et architecturale chez les 27 espèces incubantes (échantillonnage d'environ 500 oursins). Cette étude de la disparité interspécifique a été complétée par une étude de la variabilité intraspécifique chez une espèce de référence endémique à l'archipel des Kerguelen, l'échinidé Abatus Cordatus. L'étude de la disparité a été menée sur 2 aspects : les pédicellaires (observation des différentes morphologies) et les plaques ambulacraires et interambulacraires (recensement d'environ 75000 plaques). Un troisième objectif a consisté à mieux comprendre la fabrication des tests d'oursins. Les résultats montrent que le nombre de branches fasciolaires ne justifie en aucun cas la distribution des espèces dans les principaux genres. L'étude des extensions architecturales du labre et des plaques sternales a révélé l'existence d'une relation entre ces 2 caractères chez Abatus et Tripylus. Chez Abatus, des phénogrammes ont déterminé 2 groupes morphologiques, le premier rassemblant des espèces de forme ronde et le second des morphologies plus allongées. Chez Abatus cordatus, il n'existe pas de structuration géographique nette de la disparité architecturale. Le genre Amphipneustes, est envisagé comme un groupe hétérogènes ; plusieurs modifications systématiques sont proposées. Cette thèse a permis de mieux comprendre la dynamique de fabrication des tests. Des asymétries observées, quant à la position architecturale du périprocte et des fascioles sur les tests, résultaient d'une utilisation stricte de la numérotation de Loven. La recherche de la dynamique de construction des tests a mis à jour de vraies et de fausses asymétries. Finalement, le degré de symétrie de ces oursins est beaucoup plus achevé que la numérotation des plaques ne le laissait supposer.

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Chiu, Sein-tuck. "Aspects of the ecology of Anthocidaris crassispina (echinodermata: echinoidea) in Hong Kong /." [Hong Kong : University of Hong Kong], 1987. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1233571X.

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Brockington, Simon. "The seasonal ecology and physiology of Sterechinus neumayeri (Echinodermata: Echinoidea) at Adelaide Island, Antarctica." Thesis, Open University, 2001. http://oro.open.ac.uk/58168/.

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This study used an energy budget approach to record changes in the biology of the Antarctic sea urchin Sterechinus neumayeri in relation to environmental seasonality (i. e changes in chlorophyll standing stock and seawater temperature) over an unbroken two year period. Chlorophyll standing stock showed a brief but intense bloom each austral summer which contrasted with prolonged winter minima. Benthic chlorophyll standing stock, as recorded from sediment cores showed a similar cycle. Seawater temperature varied between -1.8°C and +1.2°C. Feeding activity was highly seasonal and closely correlated to chlorophyll standing stock. Feeding ceased during the austral winter of 1997 and 1998 for 6 and 4 months respectively. Metabolism, as measured by oxygen consumption and also ammonia excretion showed strong seasonality, with relatively brief 3 to 4 month periods of elevated activity in the austral summer contrasting with prolonged winter dormancy. Laboratory studies indicated that only 10-15% of the 3 fold seasonal rise in metabolism was caused directly by temperature (Q10=2.5) and that 80- 85% was related to increased physiological activity associated with feeding. Growth rate was measured over one year and was very slow. Comparison with other studies indicated that echinoid growth rate is strongly dependent on food availability, but that maximal growth rate is limited by seawater temperature, or by a co-varying factor. S. neumayeri is an annual spawner and histology was used to describe both the vitellogenic cycle and also to calculate reproductive output. Comparison with other published studies worldwide indicated that reproductive output is highly dependent on food availability, and that maximal reproductive output is not limited by temperature. Although the overall P: B ratio was low, the ratio of reproductive production to total production was higher than expected. These results indicated that due to the low metabolic rate only 12-16% of total body energy levels were used to endure the prolonged non-feeding polar winter. The overall annual growth efficiency was greater than for warmer water species, due to the larger relative contribution to reproductive output.

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Brosseau, Olivier. "Phylogénie moléculaire et analyse morphométrique des pédicellaires et du test des Cidaroida (Echinodermata, Echinoidea)." Paris, Muséum national d'histoire naturelle, 2005. http://www.theses.fr/2005MNHN0023.

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La dernière révision des Cidaroida (Echinodermata, Echinoidea) date du début du 20e siècle (Mortensen, 1928). Mortensen y développe l'utilisation des pédicellaires à tous les niveaux de classification. Mais ce groupe reste peu étudié et est reconnu pour les difficultés de classification qu'il présente (Smith et Whright, 1989). L'objectif de cette thèse est donc de dégager des méthodes et des axes d'exploration pour une meilleure compréhension de la systématique et de l'histoire évolutive des Cidaroida. Les travaux se divisent en trois parties : 1- une analyse de la variabilité et de l'ontogenèse des pédicellaires ; 2- une étude de la croissance post-larvaire sur des populations de Stylocidaris affinis ; 3- la première phylogénie moléculaire de l'ensemble de groupe (27 taxa de Cidaroida), basée sur l'analyse, en maximum de parcimonie, de deux marqueurs moléculaires (28S-D1 et COI). L'analyse morphométrique des petits pédicellaires globifères permet d'expliquer l'importante variabilité de forme par des allométries statiques. Les différentes catégories de pédicellaires chez Stylocidaris affinis et Prionocidaris sp. Sont interprétées par des processus hétérochroniques. Les conséquences taxonomiques de la variabilité sont discutées. La croissance du test est expliquée par des allométries de croissance qui peuvent conduire à des différences morphologiques importantes en fonction de l'âge du spécimen observé. De plus, les analyses mettent en évidence des changements d'allométries qui correspondent à l'apparition des pores génitaux (maturité sexuelle). L'approche de phylogénie moléculaire apparaît prometteuse pour clarifier les relations de parenté au sein du groupe. La monophylie des Cidaroida est soutenue dans deux analyses. En revanche, les Cidaridae ne sont pas monophylétiques du fait de la présence de Psychocidaris oshimaï (Psychocidaridae) dans le clade. La monophylie du genre Goniocidaris est quant à elle fortement soutenue
The last revision of the Cidaroida (Echinodermata, Echinoidea) dates back to the beginning of the 20th century (Mortensen, 1928). In this work, Mortensen stressed the use of characters of the pedicellariae for classificatory purpose at every level of the taxonomy. Since Mortensen efforts to clarify the taxonomy of the Cidaroida, this group remained seldom studied (Smith et Whright, 1989). It seemed therefore necessary to revaluate the relevance of the morphological characters classically used in the classification of the Cidaroida. In the present study, I explored three main research approaches based on different exploratory methods in order to come to a better understanding of the systematics and evolutionary history of the Cidaroida. First, I investigated the variation and ontogenesis of a number of morphological characters of the pedicellariae. Secondly, I examined the post larval growth in different populations of Stylocidaris affinis. Finally, I used molecular sequences (28S-D1 and COI) to perform the first phylogenetic reconstruction of 27 taxa, representative of the whole group, using the parsimony criterion. Using a morphometric approach, I showed that the observed variability in shape of the globiferous pedicallariae can be explained by static allometries. I also showed that the different types of pedicellariae observed on Stylocidaris affinis and Prionocidaris sp. Can be interpreted in term of heterochronic processes. As a consequence I discussed the taxonomic implication of these results. The test growth was explained by growth allometry that may lead to significant morphological differences. Moreover, drastic changes in allometric patterns were shown to be related to the development of the genital pores at sexual maturity. The phylogenetic reconstruction showed the monophyly of the order Cidaroida. However, the family Cidaridae was monophyletic whereas the genus Goniocidaris was well supported by both Jackknife and Bremer indices

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Rhora, Jennifer. "The effect of chromium vi on the production and behavior of lytechinus variegatus (echinodermata echinoidea) /." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001118.

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Rolet, Gauthier. "Structure et rôle du caecum gastrique des échinides détritivores: étude particulière d'Echinocardium cordatum, Echinoidea: Spatangoida." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209654.

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Les spatangoïdes (échinides détritivores fouisseurs) possèdent un volumineux caecum qui s’ouvre au début de l’estomac, le caecum gastrique. Ce caecum est ‘distendu’ :il est toujours gorgé d’un liquide incolore dont la nature est inconnue. Les sédiments ingérés par ces oursins et qui occupent le reste du tube digestif, ne pénètrent jamais dans le caecum. La fonction du caecum gastrique n’est pas claire: il sécréterait des enzymes dans l’estomac, serait un site d’absorption, ou encore abriterait une microflore cellulolytique. En prenant pour modèle l’un des échinides fouisseurs les plus étudiés, Echinocardium cordatum, ce travail tente d’élucider le rôle du caecum gastrique, et s’intéresse plus particulièrement à l’étude de son contenu.

Les résultats indiquent que le caecum gastrique d’E. cordatum contient de l’eau de mer. L’entrée d’eau de mer dans le caecum a été visualisée en la colorant et des caractéristiques communes au liquide caecal et à l’eau de mer environnante ont été observées: une même osmolarité, les mêmes particules détritiques en suspension et les mêmes communautés bactériennes. Le caecum gastrique contient de la matière organique en suspension (détritus, bactéries transitoires); il est également absorbant. Ses capacités d’absorption ont été comparées à celles de l’estomac et de l’intestin grâce à un dispositif expérimental particulier :les chambres de Ussing. Les résultats ont montré que les entérocytes du caecum et de l’intestin participent davantage au transfert de glucose vers la cavité coelomique que ceux de l’estomac.

Un schéma de la circulation de l’eau de mer dans le tube digestif est proposé. L’eau de mer qui circule à la surface du corps de l’oursin et qui provient de la surface des sédiments atteint la cavité buccale, une circulation entretenue par la ciliature des clavules (piquants ciliés). Le péristaltisme de l’œsophage et celui du siphon assurent l’entrée d’eau de mer dans le tube digestif. Une partie de cette eau entre dans le siphon qui l’amène dans l’intestin d’où elle est entraînée à l’extérieur avec le bol alimentaire. L’eau de mer qui n’est pas prélevée par le siphon peut atteindre l’entrée du caecum gastrique. Un système de gouttières a été mis en évidence à l’entrée du caecum. Il s’étend de l’estomac au début du caecum où les gouttières sont flagellées, et acheminerait l’eau de mer dans la lumière caecale. Les différences de pression osmotique entre le liquide caecal et le liquide cœlomique permettraient le transfert d’eau depuis le caecum vers la cavité cœlomique. Une quantité d’eau similaire devrait alors être éliminée de la cavité coelomique. Cette élimination semble se faire dans le caecum intestinal, l’eau serait ensuite éliminée par l’anus.

D’après nos observations, le caecum gastrique pourrait être le site d’une digestion et d’une absorption de la matière organique détritique de l’eau de mer. Si cette hypothèse est exacte, E. cordatum serait alors un détritivore particulièrement ‘complet’, digérant non seulement la fraction détritique des sédiments mais aussi celle en suspension dans l’eau de mer. Ce modèle pourrait correspondre à tous les échinides atélostomes (spatangoïdes & holastéroïdes) qui, outre la présence d’un caecum gastrique bien développé et rempli de liquide, ont en commun d’être fouisseurs, et d’entretenir une circulation d’eau dans leur terrier grâce à des clavules groupés en fascioles.

Spatangoids (burrowed deposit-feeding echinoids) have a large caecum, which opens at the beginning of the stomach, the gastric caecum. It is always swollen, filled with a colorless liquid whose nature is unknown; sediments ingested by sea urchins fill the rest of the digestive tract but never enter in the caecum. The function of the gastric caecum is unclear: it would secrete enzymes in the stomach, would be a site of absorption, and/or would harbor a cellulolytic microflora. By taking as model one of the most studied burrowing echinoids, Echinocardium cordatum, this study attempts to highlight the role of the gastric caecum by examining its contents.

Results indicate that the gastric caecum of E. cordatum contains seawater. Seawater inflow into the caecum was visualized using dye. The caecal liquid and the surrounding seawater were demonstrated to have similar characteristics: the same osmolarity, the same suspended particles and the same bacterial communities. The gastric caecum contains suspended organic matter (detritus, transient bacteria) and is also involved in absorption. Absorption and transfer of glucose were compared between the gastric caecum, the stomach and the intestine, using a particular experimental device: the Ussing chamber. The results showed that the enterocytes of the caecum and of the intestine were more involved in glucose transfer to the coelomic cavity than those of the stomach.

Seawater circulation in the digestive tube is tentatively described. Seawater currents along the body of the sea urchin originate from the sediment surface and reach the mouth; this circulation is generated by ciliae of specialized spines, the clavules. Peristalsis of the esophagus and of the siphon induces seawater to enter the mouth and to move along the digestive tube. Part of this water enters the siphon, being then transported to the intestine, and driven outside via the anus. Seawater that has not been taken by the siphon can reach the opening of the gastric caecum. A system of grooves occurring at the entrance of the caecum extends from the anterior stomach to the proximal part of the caecum where it is flagellated; these grooves could transport seawater in the caecal lumen. Differences in osmotic pressures between the caecal liquid and the coelomic liquid could transfer water from the caecum to the coelomic cavity. A similar uptake of water could then be removed from the coelom through the wall of the intestinal caecum, and water be eliminated from the digestive tube via the anus.

According to our observations, the gastric caecum could be specialized in digestion and absorption of detrital organic matter occurring in seawater. If this hypothesis is correct, E. cordatum would be a deposit-feeder feeding both on the detritus fraction of the sediments and on that of seawater. This model could fit all Atelostomata echinoids (spatangoids & holasteroids) which, besides the presence of a well-developed gastric caecum filled with liquid, have in common the burrowing behaviour, and the maintenance of seawater currents in their burrows owing to the action of clavules grouped into fascioles.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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De, Ridder Chantal. "La nutrition chez les échinodermes psammivores. Etude particulière du spatangide fouisseur, Echinocardium cordatum(Pennant)(Echinodermata, Echinoidea)." Doctoral thesis, Universite Libre de Bruxelles, 1986. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213551.

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16

Vellutini, Bruno Cossermelli. "Desenvolvimento e ciclo reprodutivo da bolacha-do-mar Clypeaster subdepressus (Echinodermata: Echinoidea) de São Sebastião, SP." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-17022009-105310/.

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Desenvolvimento e ciclo reprodutivo da bolacha-do-mar Clypeaster subdepressus (Echinodermata: Echinoidea) de São Sebastião, SP Resumo: Este trabalho descreve o desenvolvimento embrionário, larval e juvenil da bolacha-do-mar Clypeaster subdepressus sob microscopia de luz e eletrônica de varredura. Analisamos também o ciclo reprodutivo da espécie a partir de cortes histológicos das gônadas. A evolução morfológica da ordem Clypeasteroida (bolachas-do-mar), cerca de 55 milhões de anos atrás, esteve relacionada à ocupação de fundos arenosos. Dados morfológicos recentes e fósseis sugerem que durante a evolução das bolachas-do-mar houve retenção de características juvenis na fase adulta. Obtivemos gametas através da injeção de KCl em indivíduos adultos e fizemos a fecundação in vitro. Mantivemos os embriões e larvas em culturas a 26°C, e alimentamos as larvas com microalgas. Os óvulos (diâmetro médio de 160µm) são esféricos translúcidos e brancos. Após a entrada do espermatozóide, o envelope vitelínico endurece entre 2 e 6min; o pró-núcleo masculino inicia a migração da região periférica do óvulo até o centro 5min depois, levando 12min à 0,1µm/s para se fundir ao pró-núcleo feminino. As clivagens são holoblásticas, com a formação de macrômeros, mesômeros e micrômeros. A blástula forma-se entre 3,5 e 6,5h após a fecundação (hpf), desenvolve cílios e eclode da membrana de fertilização 7,5hpf. A gastrulação inicia-se na placa vegetativa com a ingressão unipolar das células mesenquimais primárias 10hpf. A extensão do arquêntero, ingressão das células mesenquimais secundárias e formação do esqueleto larval estendem-se até 30hpf. Em menos de 48hpf os espaços celômicos estão formados e no terceiro dia as larvas iniciam sua alimentação. O hidróporo abre-se na superfície abanal da larva e a invaginação do vestíbulo ocorre entre o braço pós-oral e o póstero-dorsal, do lado esquerdo, ao redor do quinto dia. O vestíbulo funde-se ao celoma esquerdo formando o rudimento, que desenvolve espinhos e pés ambulacrais ainda dentro da larva. As larvas tornam-se competentes ~20d após a fecundação e somente iniciam a metamorfose pela manhã, após contato com areia do habitat dos adultos ou microalgas. Após a eversão completa do rudimento, o epitélio larval regride por 1h30min. Jovens pós-metamórficos não têm boca ou ânus; possuem 15 espinhos e 15 pés ambulacrais (de 2 tipos); 5 esferídios na superfície oral; a superfície aboral ainda não possui esqueleto, exceto os remanescentes do esqueleto larval. Rudimentos do esqueleto da lanterna de Aristóteles estão organizados em 5 conjuntos com 1 dente, 2 hemipirâmides, 2 epífises cada; rudimento da rótula encontra-se intercalado entre os conjuntos. Hemipirâmides e dentes formam-se 2d após a metamorfose (dpm); dentes tornam-se mais robustos e as hemipirâmides se fundem formando as pirâmides 7dpm. O tubo digestório aparece e o ânus abre-se na superfície aboral 2dpm. A membrana peristomial torna-se funcional formando a boca 7dpm. Pedicelárias oficéfalas e tridentadas surgem na região posterior 14dpm e 30dpm, respectivamente. O crescimento dos jovens criados em laboratório foi lento: jovens pós-metamórficos tinham ~250µm de diâmetro e atingiram ~500µm de diâmetro 8 meses depois. Descrevemos 6 estágios de maturação gonadal para machos e fêmeas de C. subdepressus. Encontramos estágios de proliferação e gametas maduros com maior freqüência entre dezembro e março (verão), enquanto estágios de recuperação predominaram de maio a setembro (inverno). Fêmeas apresentaram um período de recuperação mais longo do que machos. A área ocupada pelo epitélio germinativo em um túbulo gonadal em corte transversal foi menor em indivíduos maduros. No estágio prematuro, as gônadas estiveram mais pesadas. Dados sugerem que exista um ciclo reprodutivo anual nas populações de C. subdepressus em São Sebastião, onde a recuperação das gônadas ocorre no inverno, o acúmulo de nutrientes a partir de outubro e a liberação de gametas entre fevereiro e março.
Embryonic, larval, and juvenile development of the sea biscuit Clypeaster subdepressus is described with light and scanning electron microscopy. The reproductive cycle of the species is analyzed based on histological sections of the gonads. The morphological evolution of the order Clypeasteroida (sand dollars and sea biscuits), about 55 million years ago, was associated with the occupation of sand beds. Data on morphology of living and fossil echinoids suggests that during the evolution of sea biscuits juvenile characters were retained into adulthood. We obtained ripe gametes by KCl injection into the perivisceral coelomic cavity of adults and fertilized the eggs in vitro. We kept embryos and larvae in cultures at 26 °C and fed larvae with microalgae. Eggs (mean diameter of 160 m) are spherical, translucent, and white. After sperm entry, the vitelline envelope hardens between 2 and 6 min; male pro-nucleus begins to migrate towards the center of the egg 5 min later, taking 12 min at 0.1 m/s to fuse with the female pronucleus. Cleavages are holoblastic with the formation of macromeres, mesomeres, and micromeres. Blastulae are formed between 3.5 and 6.5 h after fertilization (hpf), develop cilia, and hatch 7.5 hpf. Gastrulation begins on the vegetal plate with the unipolar ingression of primary mesenchyme cells 10 hpf. Archenteron extension, ingression of secondary mesenchyme cells, and the formation of larval skeleton occurs until 30 hpf. In less than 48 hpf the celomic pouches are formed and on day 3 larvae begin to feed. Hidropore opens on the abanal surface of larvae while vestibule invagination takes place between the post-oral and postero-dorsal arms on the left side 5 dpf. Vestibule fuses with the left celom forming a rudiment which develops spines and podia still inside the larvae. Larvae become competent _20 d after fertilization and only metamorphose in the morning, after contact with sand from adult populations or food. After complete eversion of the rudiment, the larval epidermis retraction takes 1 h 30 min. Post-metamorphic juveniles do not have anus or mouth; they have 15 spines and 15 podia (of 2 types); 5 sphaeridia on the oral surface; aboral surface does not have plates, except for the remnants of larval spicules. Rudiments of the Aristotles lantern are organized in 5 groups. Each group has 1 tooth, 2 hemipiramids, and 2 epiphysis; a rudiment rotula is placed between the groups. Hemipiramids are formed 2 d after metamorphosis (dpm); teeth become more robust and hemipiramids fuse into piramids 7 dpm. The digestive tract appears and the anus opens on the aboral surface 2 dpm. The peristomial membrane is functional and the mouth opens 7 dpm. Ophicephalous and tridentate pedicellariae appear on the posterior region 14 dpm and 30 dpm, respectively. Growth of juveniles reared in the laboratory was slow: post-metamorphic juveniles were _250 m in diameter and reached _500 m 8 months later. We described 6 stages of gonadal growth in males and females of C. subdepressus. We found premature stages and ripe gametes more frequently between December and March (summer), while recovery stages were dominant from May until September (winter). Females have a longer period of growing stage than males. The area occupied by the germinal epithelium on a transverse section of a gonadal lobe is lower in mature stage. Gonads are heavier during the premature stage. Data suggest that C. subdepressus from São Sebastião has an annual reproductive cycle where gonadal recovery occurs during winter, nutrient storage by October, and spawning between February and March.

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José, de Barros Lima Eduardo. "Dinâmica populacional de Echinometra lucunter (Linnaeus, 1758) (Echinodermata: Echinoidea) na praia de Muro Alto, Ipojuca, Pernambuco." Universidade Federal de Pernambuco, 2006. https://repositorio.ufpe.br/handle/123456789/673.

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O equinóide regular Echinometra lucunter é uma espécie comestível e comum ao longo de toda a costa brasileira, sendo um importante indicador do limite entre o médio e o infralitoral, com participação ativa como agente bioerosivo dos recifes. Este trabalho teve por objetivo investigar a dinâmica populacional numa poça de maré, na praia de Muro Alto, litoral sul de Pernambuco, no período de agosto de 2004 a agosto de 2005. Cerca de 2.635 exemplares foram capturados, durante as marés baixas de sizígia, em 42 m2 de área amostrada. A densidade média registrada foi de 62,74 ind.m-2, sendo a maior densidade observada em outubro/2004 (112,17 ind.m-2) e a menor em abril/2005 (20 ind.m-2). O coeficiente de dispersão revelou um padrão de distribuição agregado. O tamanho médio do diâmetro maior da carapaça foi de 26,35 mm, variando de 17,58 a 35,58 mm, ao passo que a altura da carapaça variou de 8,24 a 17,85 mm e seu valor médio foi de 12,71 mm. O maior índice gonadal médio registrado foi de 4,26% em outubro/2004 e o menor foi de 0,71% em março/2005. A razão sexual foi de 1,12:1, com variação temporal significativa. A primeira maturação ocorreu em indivíduos a partir de 20 mm de diâmetro. Foi registrado um recrutamento anual e estimados os parâmetros de crescimento: tamanho infinito, taxa de crescimento e mortalidade com valores de 115 mm, 0,280 ano-1 e 0,600 ano-1, respectivamente. Os resultados deste trabalho assinalam diferenças e similaridades para E. lucunter de outras localidades, como também com outras espécies de equinóides regulares, quanto aos parâmetros de crescimento, taxa de mortalidade, padrão de recrutamento, densidade e padrão de distribuição, ciclo reprodutivo e gametogênico

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Sciani, Juliana Mozer. "Estudos toxinológicos do ouriço-do-mar Echinometra lucunter." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-24092012-081004/.

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Echinometra lucunter, o ouriço-do-mar responsável por 50% dos acidentes por animais marinhos, causa inflamação e dor quando os espinhos entram na pele, efeitos atribuídos ao trauma mecânico, além de acidentes por ingestão de ovas. O líquido celômico e o extrato aquoso de espinhos foram fracionados e purificados até a obtenção de moléculas puras, que foram testadas em modelos de inflamação. Foram feitas análises histológicas do espinho e de atividade enzimática do extrato de espinho. Foi isolada uma molécula do espinho e um peptídeo do líquido celômico, que causaram inflamação e dor. Foi verificada atividade enzimática de catepsina B/X. Foi observada uma estrutura histológica organizada no espinho, com células entre a porção calcificada, algumas contendo grânulos eletrodensos com conteúdo protéico, típicas secretoras. Conclui-se que o espinho e o líquido celômico de E. lucunter possuem toxinas inflamatórias, que participam do envenenamento e o espinho tem células secretoras de toxinas. A catepsina pode auxiliar no mecanismo de reparação do espinho, quando quebrado.
Echinometra lucunter, the sea urchin responsible for 50% of marine animals accidents, cause inflammation and pain by the spine penetration, effects attributed to the mechanical trauma. Accidents were reported after the ingestion of raw. The celomic fluid and spines were fractionated and purified, procedure repeated until pure molecules were obtained, tested for inflammation models. Histological analyses and enzymatic assays were performed. A molecule from spines and a peptide from the celomic fluid caused inflammatory effects. Moreover, a cathepsin B/X activity could be identified in the spines. An organized histological structure in the spine was observed, with cells embedded in a calcified matrix, as well as granulous cells displaying proteic contents, typical of secretory cells. It was possible to conclude that the spine and the celomic fluid of E. lucunter do contain inflammatory toxins that prolong the spine puncturing event itself, and the spine possesses a toxin secretory structure. The cathepsin would be present in a mechanism of tissue remodeling.

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Egea, Emilie. "Histoire évolutive, structures génétique, morphologique et écologique comparées dans un complexe d'espèces jumelles : Echinocardium cordatum (Echinoidea, Irregularia)." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22017.

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Echinocardium cordatum (Pennant 1777) oursin irrégulier abondant des zones côtières tempérées a longtemps été considéré comme une espèce cosmopolite dont la vaste aire de distribution était la conséquence directe des capacités de dispersion de sa larve planctotrophe. L’étude couplée des caractéristiques génétiques [génomes mitochondrial et nucléaire (introns+microsatellites)], morphologiques (étude basée sur 20 indices morphométriques) et écologiques (distribution géographique à petite ou grande échelle, et cycle de maturation gonadique) a révélé la présence d’un complexe d’espèces jumelles dont la différenciation génétique est accompagnée d’une différenciation morphologique statistique ainsi que de différenciations écologiques plus ou moins fines. Ces espèces occupent des aires de distribution limitées (clade A : Atlantique, clade SP : Pacifique Sud, clade NP : Pacifique Nord, clade B2 : Méditerranée, et clade B1 : Méditerranée et côtes atlantiques de l’Ibérie). D’après la reconstruction de l’histoire évolutive de ce complexe, à partir des données paléontologiques et moléculaires, ces espèces auraient divergé il y a 3 (B1-B2) à 10 (A-reste) millions d’années sous l’effet de perturbations géologiques et paléoclimatiques (fermeture de la Téthys, crise messinienne de salinité et glaciations Plio-Pléistocène). Le polymorphisme morphologique et moléculaire apparaît réduit chez B1 suggérant un effectif efficace historique de cette espèce réduit. L’analyse des flux géniques contemporains révèle que les clades A et B1 échangent toujours des gènes, alors que les clades B1 et B2, ont mis en place un isolement reproducteur efficace empêchant l’hybridation. Par ailleurs, les capacités de dispersion des espèces de ce complexe sont importantes (plus de 3000 km), mais moindres comparées à d’autres espèces du genre, notamment E. mediterraneum, qui bien qu’ayant subi les mêmes évènements géologiques n’a pas formé d’espèce depuis son apparition il y aurait 28 millions d’années. D’un point de vue évolutif, les taxons à forte capacité de dispersion présenteraient des tailles efficaces de populations importantes, ainsi qu’une aire de répartition étendue et peu de différentiation génétique entre localités ; autant de caractéristiques qui devraient ralentir la vitesse de spéciation dans ces taxons. Si cette hypothèse semble se vérifier chez E. mediterraneum, il n’en est pas de même chez E. cordatum qui malgré des effectifs efficaces apparemment importants et une différenciation des populations à l’échelle régionale faible, présente une dynamique se spéciation plus rapide. Il faut envisager que d’autres caractéristiques soient à l’origine de cette différence de dynamique de spéciation, et la comparaison des exigences écologiques des deux taxons ainsi que l’isolement de la molécule responsable de la réaction acrosomique, la bindine, pourraient apporter des éléments de réponse aux nouvelles questions soulevées
Echinocardium cordatum (Pennant 1777) an abundant irregular sea urchin from the coastal temperate zones has long been considered as a cosmopolitan species which wide distribution area was the direct consequence of its planktotrophic larvae high dispersal abilities. A combined study of the genetic [mitochondrial and nuclear genomes (introns+microsatellites)], morphologic (based on 20 morphometric indices) and ecologic (geographic distribution at fine or large scale, and gonad maturation cycle) characteristics reveals that this taxon is a complex of cryptic species for which genetic differentiations concurred with morphological and ecological ones. The different species each occupy a limited geographic areas (clade A : Atlantic, clade SP : South Pacific, clade NP : North Pacific, clade B2 : Mediterranean sea, et clade B1 : Mediterranean sea and Atlantic coasts of Iberia). According to the complex species evolutionary history reconstruction, based on fossils and molecular data, the different species diverged between 3 (B1-B2) and 10 (A-rest) million years ago, driven by geologic and paleoclimatic perturbations (Tethys closure, messinian salinity crisis, Plio-Pleistocene glaciations). Molecular and morphologic polymorphisms appear reduced in B1, suggesting a reduced historical effective size. The contemporaneous genetic flux analysis reveals that clades A and B1 exchange genes whereas clades B1 and B2 developed an efficient reproductive isolation preventing hybridization. Though dispersal abilities of the complex species are high (more than 3000 km), they appear to be smaller than those of other species of the same genera, particularly E. mediterraneum which undergone the same geological perturbations without splitting into several species since its appearance some 28 million years ago. From an evolutionary point of view, taxa with high dispersal abilities should exhibit important population effective sizes, wide distribution areas and weak genetic differentiation between localities, properties that should slow species formation within these taxa. If this hypothesis seems verified in E. mediterraneum, it is not the case in E. cordatum for which the apparent high effective size and weak regional structure contrast with the fast speciation dynamics. It seems that other characteristics might be responsible for the speciation dynamic differences, and the comparison of the two taxa ecological requirements, as well as the isolation of the gene coding for the protein responsible of the sperm specific attachment, the bindin, should bring elements to answer these questions

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Varotto, Ricardo Silva. "Modelagem matemática do crescimento somático e mortalidade do ouriço-do-mar Cassidulus mitis Krau, 1954 (Echinoidea : Cassidulidae)." Universidade Federal do Rio de Janeiro, 2001. http://hdl.handle.net/11422/3513.

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Cassidulus mitis Krau, 1954 é uma espécie de ouriços-do-mar de distribuição geográfica muito restrita sendo somente encontrados em algumas áreas no estado do Rio de Janeiro. A única população densa conhecida desta espécie encontra-se na Praia Vermelha, RJ. O crescimento somático de C. mitis de uma população localizada na Praia Vermelha, RJ, foi analisado através dos dados referentes à distribuição mensal das frequências de tamanho entre dezembro de 1998 e abril de 2000, bem como por um experimento de marcação e recaptura. Estes dados foram utilizados na estimativa dos parâmetros necessários à construção de curvas de crescimento definidas por quatro diferentes modelos matemáticos através de regressão não-linear (Brody-Bertalanffy, Richards, logístico e Gompertz), e na estimativa da mortalidade natural da população de C. mitis na Praia Vermelha, RJ. A comparação dos modelos foi realizada pela (1) análise da soma do quadrados dos resíduos das regressões não-lineares, (2) a análise da distribuição destes resíduos e (3) pela comparação de regressões lineares realizadas entre tamanho final previsto pelos modelos e o tamanho observado nos espécimes recapturados. O modelo de Gompertz foi considerado como melhor descritor do crescimento de C. mitis. As constantes de crescimento e mortalidade estimadas pelo modelo de Gompertz foram de 0,68 ano^-1 e 0,63 ano^-1, respectivamente. Pela análise da curva de crescimento puderam ser estimados a idade da primeira maturação em 2,2 anos, a idade na qual a taxa de crescimento alcança seu valor máximo em 2,4 anos e a longevidade em 9,1 anos.
The somatic growth of Cassidulus mitis Krau, 1954, a tropical brooding species, from a population located at the Vermelha Beach, Rio de Janeiro, Brazil, was analyzed by observing the monthly size distributions from December 1998 to April 2000, as well as by a mark-recapture experiment. These data were used to estimate the parameters necessary to construct growth curves defined by four different models by means of non-linear regressions (Brody-Bertalanffy, Richards, Gompertz and logistic models), and to estimate the natural mortality of this C. mitis population. The evaluation of the models was accomplished by (1) the analysis of the sum of the square residuals from the former non-linear regressions, (2) the analysis of the distribution of these residuals and (3) the comparison of linear regressions between the size predicted by the models and the size observed, from the recaptured specimens. The curve assigned by the Gompertz equation was considered the best one to describe the growth of C. mitis. The growth and mortality constants predicted by the model of Gompertz were 0.68 year^-1 and 0.63 year^-1, respectively. The analysis of the growth curve shows that C. mitis become potentially mature at the age of 2.2 years, shows the maximum growth rate values at 2.4 years, and has a life-span of 9.1 years.

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Tavares, Yara Aparecida Garcia. "Ecologia populacional de Mellita quinquiesperforata Leske, 1778 (Echinodermata: echinoidea: clyperasteroida) em diferentes praias do litoral do Parana, Brasil." reponame:Repositório Institucional da UFPR, 1996. http://hdl.handle.net/1884/28222.

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Orientador: Carlos Alberto Borzone
Dissertação (mestrado)- Universidade Federal do Parana, Setor de Ciencias Biologicas
Resumo: O equinóide irregular Mellita quinquiesperforata habita a região infralitoral de praias arenosas com ocorrência ao longo de toda a costa tropical e subtropical Atlântica, das Antilhas até o sul do Brasil. O presente estudo teve como objetivo analisar a distribuição espaço-temporal de M. quinquiesperforata e suas relações com as características ambientais de praias da costa paranaense, além de abordar aspectos da dinâmica populacional e biologia reprodutiva. Populações de M. quinquiesperforata foram estudadas em dez praias durante amostragens pontuais realizadas em fevereiro e março de 1993 e em duas dessas praias realizaram-se amostragens periódicas de fevereiro de 1992 à julho de 1994. As coletas foram feitas ao longo de uma transversal estabelecida em cada praia em pontos fixos de amostragem desde o início do infralitoral até profundidades de 2 à 3 m. Foram obtidos o perfil topográfico, registrados os parâmetros abióticos, temperatura e salinidade da água, altura e período de ondas e feitas análises sedimentológicas. Para o estudo morfométrico dos indivíduos de M quinquiesperforata foi utilizada a Análise de Componentes Principais (PCA). No estudo da dinâmica populacional foram estimados os parâmetros largura infinita (Loo), taxa de crescimento K, taxa de mortalidade natural Z e padrão de recrutamento à partir da distribuição de frequência de tamanho (largura da carapaça em mm) utilizando o Programa FISAT. O ciclo reprodutivo foi estudado através da vanação do índice gonadal (IG) [(peso seco das gònada/peso seco total) X 100] em 20 animais adultos (largura da carapaça > 40 mm) coletados mensalmente em dois ambientes durante um ano (1993/1994). Foram acompanhadas também as variações de dois outros índices: índice do intestino + tecidos internos (1T) e índice da caparaça (1C). A distribuição espacial dos indivíduos de M. quinquiesperforata ocorre sob a forma de um banco contínuo, paralelo à costa, cuja extensão e posição variam de acordo com o estado morfodinâmico praial. A presença de animais em todas as praias estudadas indica que os indivíduos podem viver em ambientes com diferentes graus de exposição às ondas. Em praias dissipativas e intermediárias ocorrem as maiores extensões e posicionamento do banco mais afastado da costa, em oposição à uma distribuição mais restrita e próxima à linha d'água em praias reflectivas. Foi constatada a existência de uma separação por tamanho: animais juvenis (com largura da carapaça < 40 mm) ocorrem afastados dos adultos, iniciando a faixa de indivíduos do banco ou intercalando-se aos indivíduos maiores. O risco de predação dos juvenis por parte dos adultos poderia explicar esta exclusão por faixa etária. O acompanhamento periódico numa praia dissipativa/intermediária registrou um deslocamento migratório dos animais como resposta as mudanças sazonais do estado morfodinâmico praial. Foram descritas variações morfométncas entre as populações estudadas e propostas variedades fenotípicas para ambientes dissipativos, intermediários e reflectivos. A concavidade da carapaça, a largura das lúnulas ambulacrais e comprimento da lúnula anal foram as variáveis que mais distinguiram-se entre os indivíduos das diferentes praias. Os indivíduos estudados em duas praias com distinta caracterização morfodinâmica apresentaram como característica da distribuição etária uma constante moda adulta dominante (40 - 60 mm de largura da carapaça). Na praia reflectiva não foi registrado recrutamento para os anos de 1993 e 1994. Na praia dissipativa/intermediária foi registrado um anual e bem sucedido recrutamento permitindo o cálculo dos parâmetros populacionais para todo o período. O método ELEFAN I estimou a largura infinita (Loo) em tomo de 61 mm e a taxa de crescimento (K) em aproximadamente 0,68. A taxa de mortalidade natural (Z) obtida pelo método de curva de captura foi em tomo de 1,14. O padrão de recrutamento estendeu-se do inverno até o final da primavera. O acompanhamento da variação do índice gonadal (IG) nestas duas praias revelou épocas distintas para o momento da desova (primavera na praia dissipativa/intermediária e verão na praia reflectiva), possivelmente relacionadas a diferenças nos fatores ambientais como salinidade ou morfodinamismo praial. Não observou-se correlação entre as variações dos índices gonadal (IG) e do intestino + tecidos internos (IT): descartando o intestino, componente principal dos tecidos internos, como órgão de estocagem de recursos para a reprodução. Na praia reflectiva, no entanto, foram verificadas correlações inversas entre o índice gonadal (IG) e o da carapaça (1C), sugerindo a possibilidade de que recursos de estruturas como o epitélio, espinhos e carapaça estejam sendo alocadas para reprodução.
Abstract: The irregular echinoid M. quinquiesperforata inhabits the infralitorai zone of sandy beaches, being distributed along the tropical and subtropical Atlantic coast, from the Antilhes to southern Brazil. The present work aims to analyse the spatial and temporal distribution of M. quinquiesperforata and its relationship with the environmental features of Parana coast beaches and also discuss aspects of the population dynamics and reproduction. M. quinquiesperforata species populations were studied in ten beaches during a sampling realized in february and march 1993 and monthly in two beaches at february 1992 to july 1994. The samples were collected in fixed stations distributed along a transect from the infralitorai zone until 2 - 3 m water depth. The topographic profile and the abiotics parameters, temperature and water salinity, wave heights and period and sediment were obtained. Ln the morphometry study, a multifatorial analysis PCA was used. In the population dynamic study the parameters infinitive width (Lao), growth rate K, total mortality rate Z and recruitment pattern were obtained from size-frequency distribution using the software FIS AT. Reproductive cycle was studied through the vanation of a gonad index (IG) [(dry weight gonad/dry weight whole animal) X 100] of 20 adults animals (test width > 40 mm) sampled monthly in two beaches during one year (1993/1994). Two other indices were calculated : intestine + inner tissues indice (IT) and test indice (IC). M. quinquiesperforata is distribued in a continuous bed parallel to the coast, its extension and position varying according to the morphodynamic beach states. The occurence of the animals in ail beaches indicated that they can survive in different environmental degree of wave exposure. The greatest beds occurred m dissipatives and intermediates beaches occupying offshore positions; while in reflectives beaches the beds were registered near to the water line. A size separation was noticed: the juvenile animals (test width < 40 mm) are distant from the adults, bouding the bed initial or intercalating themselves with greater animals. This size exclusion could be explained by the juveniles predation risk by adults. In the periodic sampling in a dissipative/intermediate beach, a migratory displacement of the animals was registered as a response to the sazonal changes in the beach morphodynamic state. Morphometric changes were described among the populations and phenotic varieties were proposed to dissipative, intermediate and reflective environments. The test profile, the ambulacral lunule width and the anal lunule lenght were the variables that most distinghished between individuals of different beaches. The populations of two beaches with distinct wave exposures presented a size-frequency distribuition with a constant and dominant adult modal group (40 - 60 mm test width). In the reflective beach no population recruitment was registered in the years 1993 and 1994. In the dissipative/intermediate beach was registered an annual and successful recruitment, allowing the growth parameters to be calculated for the whole penod. ELEFAN I method gave an estimated infinitive width (Loo) of 61.0 mm and a growth rate K of 0.68. Total mortality rate Z obtained by catch curve method was 1.14. The recruitment pattern was stablished from winter to the end of spring. IG variation showed two spawning times (spring in the dissipative/intermediate beach and summer in the reflective beach) which could be attributed to the environmental factors as salinity and beach morphodynamics. No correlations were observed between IG and IT changes, indicating that the intestine should not be considered as a resource stock organ for the reproduction. IC and IG correlations in the reflective beach could be attributed to the input of resources from the structures as epithelium, spines and test to reproduction.

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Wolcott, Ray. "A Comparison of Aeration Methods and Diets for Larval Culture of the Edible Sea Urchin, Tripneustes ventricosus (Echinodermata: Echinoidea)." NSUWorks, 2002. http://nsuworks.nova.edu/occ_stuetd/293.

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Tripneustes ventricosus (Lamarck 1816), a major near-shore herbivore in the Atlantic and Caribbean, has been harvested for human consumption in the Caribbean for centuries (Lawrence 2001a, b), occasionally at rates that exceed sustainability (Smith & Berkes 1991), and is among the species having economic importance (Lawrence & Bazhin 1998). Tripneustes ventricosus has recently been observed on the forereef controlling macroalgal growth in the absence of Diadema antillarum (Woodley 1999, Aronson & Precht 2000, Haley & Solandt 2001). Large-scale culturing has the potential to produce T. ventricosus in sufficient numbers to be used for: bioremediation of coral reef degradation, restocking of nearshore habitats, and the development of an aquaculture industry for one or more Caribbean islands. Heretofore, T. ventricosus has never been cultured from fertilization to exotrophic (feeding) juvenile. This work presents the results of experiments designed to measure the effectiveness of aeration methods and diets applicable for large-scale larval culture. Airlift aeration, used successfully in larger scale systems, was not effective in the 3.78-L (1-gallon) jars used for my experiments. Success was obtained in cultures reared without mechanical aeration. Fifteen percent of the larvae survived to day 33 and the 6-armed stage was reached. However, paddle aeration, used successfully in many small-scale experimental designs, produced the highest survival rates. Rhodomonas sp. produced the most rapid development (23 days to metamorphosis). Isochrysis aff. galbana (Tahitian strain) supported slower development (36 days to metamorphosis), but produced the highest (48%) survival rate. Cryptomonas sp., a mixture of Dunaliella tertiolecta and Isochrysis, and a mixture of Rhodomonas and Isochrysis were also tested and found to be inferior to the results produced with Isochrysis. Conclusions include: Tripneustes ventricosus larvae can be successfully cultured. While more rapid development occurs when the larvae are fed Rhodomonas, Isochrysis offers a more favorable combination of survival rate and development time. The perimetamorphic period, from rudiment formation to feeding juvenile, included a life stage heretofore unreported for T. ventricosus. Referred to as echinoporculus for its fanciful resemblance to a young pig, this stage was observed as the immediate metamorphic result in nearly half of the metamorphosed animals. Covering was observed in juveniles as small as 1.5 mm. The adornment remained on the aboral surface regardless of the juvenile’s orientation.

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Guimarães, Caren Daiane Mouzinho. "Identificação e distribuição das espécies de Mecaster (Echinodermata: Echinoidea) do cretáceo da bacia de Sergipe-Alagoas, Nordeste do Brasil." Universidade Federal de Sergipe, 2016. https://ri.ufs.br/handle/riufs/5402.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
In this work were analyzed the Spatangoids Echinoids of the species Mecaster batnensis (Coquand, 1862), Mecaster fourneli (Agassiz & Desor, 1847) and Mecaster africanus (Coquand, 1862) from the Sergipe sub-basin of the Fundação Paleontológica Phoenix collection. Among the specimens studied, there were found exemplars of the species Mecaster texanus (Roemer, 1849), that were recorded for the first time in the Sergipe Cretaceous. It was observed that the species M. batnensis and M. africanus, distributed from the Cenomanian to the Turonian showed a lower number of pore pars in the ambulacra III when compared to the others Mecaster species in this same interval. This data could indicate that this species lived in lower depths in the sediment, since the podia of those pores would be sparser. On the other hand, M. fourneli and M. texanus distributed between the Turonian and Coniacian showed a higher number of pore pairs in the ambulacra III, what could indicate that these species lived at more profound depths in the sediment and their contacts with the water-sediment interface through the podia were more effective. All the Mecaster species were present at the basin during the Turonian where they had occupied different habitats, M. batnensis and M. africanus on the other hand would search more profound places where they would live borrowed closer to the water-sediment interface and protected from predators. M. fourneli and M. texanus would prefer shallow environments where they would ride from their predadors burrowed deeply in the sediment.
Neste trabalho foram analisados os equinoides espatangoides Mecaster batnensis (Coquand, 1862), Mecaster fourneli (Agassiz & Desor, 1847) e Mecaster africanus (Coquand, 1862) provenientes da sub-bacia de Sergipe e depositados nas coleções de Invertebrados fósseis da Fundação Paleontológica Phoenix. Entre os espécimes estudados foram encontrados exemplares de Mecaster texanus (Roemer, 1849) sendo esta espécie registrada pela primeira vez para o Cretáceo de Sergipe. Foi observado que as espécies Mecaster batnensis e M. africanus distribuídos do Cenomaniano ao Turoniano apresentaram um número menor de pares de poros no ambulacro III do que as demais espécies neste mesmo intervalo, o que poderia indicar que teriam tido a capacidade de se enterrar a uma menor profundidade no sedimento, já que os pódios destes poros seriam mais espaçados. As espécies Mecaster fourneli e M. texanus foram distribuídas entre o Turoniano e o Coniaciano e apresentaram um maior número de pares de poros no ambulacro III, podendo indicar que estas espécies teriam se enterrado mais profundamente e seu contato com a interface água/sedimento através dos pódios mais efetivo. Todas as espécies de Mecaster estiveram presentes na bacia durante o Turoniano, onde teriam ocupado habitat distinto. Enquanto Mecaster batnensis e M. africanus teriam procurado locais talvez mais profundos onde teriam vivido enterrados mais próximo da interface sedimento/água e afastados de prováveis predadores, M. fourneli e M. texanus teriam preferido ambientes mais rasos onde teriam driblado seus predadores se enterrando mais profundamente no sedimento.

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Villier, Loïc. "Evolution du genre Heteraster dans le contexte de la radiation de l'ordre des Spatangoida (Echinoidea, Echinodermata) au Crétacé inférieur." Dijon, 2001. http://www.theses.fr/2001DIJOS059.

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Cook, Elizabeth J. "Psammechinus miliaris (Gmelin) (Echinodermata: Echinoidea) : factors affecting its somatic growth and gonadal growth and development, and its suitability as a species for sea urchin cultivation." Thesis, Edinburgh Napier University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410982.

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Guettaf, Mourad. "Contribution à l'étude de la variabilité du cycle reproductif (indice gonadique et histologie des gonages) chez Paracentrotus lividus (Echinodermata : Echinoidea) en Méditerranée Sud Occidentale (Algérie)." Aix-Marseille 2, 1997. http://www.theses.fr/1997AIX2A001.

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Moussa, Bourahima. "Echinofaunes maastrichtiennes et paléocènes du Bassin des Iullemmeden (Niger occidental) : quantification de la disparité morphologique chez Linthia (Echinoidea, Spatangoida) : implications biostratigraphique, paléoenvironnementale, systématique et phylogénétique." Dijon, 2001. http://www.theses.fr/2001DIJOS028.

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L'abondante échinofaune des formations maastrichtiennes et paléocènes du Bassin des Iullemmeden (Niger, Afrique occidentale) a été très peu étudiée jusqu'à présent. L'objectif de ce travail est d'acquérir une meilleure connaissance paléontologique et stratigraphique de cette échinofaune, dans le cadre d'une démarche globale à l'échelle du Bassin des Iullemmeden. Cette recherche a été focalisée sur les Linthia, notamment L. Sudanensis (s. 1. ), espèce présentant une importante extension spatio-temporelle et une grande variabilité morphologique. L'étude, réalisée selon une démarche populationnelle, appréhende quantitativement la disparité morphologique des Linthia, d'une part par l'utilisation de méthodes de morphométrie linéaire, et d'autre part, par l'utilisation d'analyses d'images, basées sur le développement en séries de Fourier. Le développement ontogénétique chez Linthia sudanensis (s. S) est marqué par une phase de croissance différentielle qui intervient très tardivement. Les Linthia du Bassin des Iullemmeden présentent des caractéristiques suffisamment discriminantes, pour justifier la distinction entre les morphes L. Payeni, L. Sudanensis brevipetala et L. Sudanensis sudanensis. Le genre Linthia posséde des caractéristiques taxonomiques dont l'interprétation permet d'envisager leur lien phylogénétique avec les Mecaster et les Periaster. Dans le Bassin des Iullemmeden, les morphes L. Payeni, L. Sudanensis brevipetala et L. Sudanensis sudanensis caractérisent respectivement le Maastrichtien, le Paléocène inférieur et le Paléocène supérieur. La configuration paléogéographique du bassin est celle d'une plate-forme carbonatée zonée, supra- à circalittorale. Celle-ci montre des relations privilégiées avec la Téthys méditerranéenne orientale.

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Lison, de Loma Thierry. "Transferts de matière et d'éléments nutritifs sur les récifs coralliens de l'île de la Réunion par deux herbivores, Tripneustes gratilla (Echinodermata, Echinoidea) et Stegastes nigricans (Pisces, Pomacentridae)." Aix-Marseille 2, 2000. http://www.theses.fr/2000AIX22055.

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Zama, Paula Caetano. "Comparação interpopulacional de caracteres morfológicos e reprodutivos do ouriço-do-mar Arbacia lixula (Linnaeus, 1758) (Echinodermata: Echinoidea) em duas localidades do litoral do estado do Rio de Janeiro." Universidade Federal do Rio de Janeiro, 2005. http://hdl.handle.net/11422/3430.

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Arbacia lixula (Linnaeus, 1758) é um equinóide comum no litoral brasileiro e, apesar disso, é pouco estudado no Atlântico Sul. Os objetivos deste trabalho foram comparar as variações morfológicas e reprodutivas dentro e entre duas populações e analisar o ciclo reprodutivo de Arbacia lixula através do índice gonadal, do índice de maturidade e da análise histológica das gônadas. Mensalmente, 15 a 20 indivíduos foram coletados por mergulho em apneia na Prainha, Arraial do Cabo e na Ponta de Itaipu, Niterói. Os indivíduos coletados foram pesados e medidos antes da dissecação. O índice dos órgãos foi calculado. Uma gônada de cada indivíduo foi analisada histologicamente para determinação dos estágios gametogênicos. O ciclo reprodutivo foi rápido e contínuo, com produção e liberação de gametas durante todos os meses do estudo. Diferenças morfológicas interpopulacionais foram encontradas entre o diâmetro, a altura, e o peso da carapaça e o comprimento da demi-pirâmide. Os resultados deste estudo sugerem a ocorrência de plasticidade fenotípica e fluxo gênico entre as duas populações de Arbacia lixula. Estudos de manipulação e genética de populações devem anteceder qualquer atividade de manejo e exploração dessa espécie.
Arbacia lixula (Linnaeus, 1758) is a common echinoid on the Brazilian coast, although there are few studies about this species in the South Atlantic Ocean. This work aims to compare morphological and reproductive traits in two sea urchin populations and verify the reproductive cycle of Arbacia lixula using gonadal index, maturity index and histological analysis of the gonads. Monthly 15 to 20 specimens were collected by free diving in Prainha, Arraial do Cabo and in Ponta de Itaipu, Niterói. The specimens captured were weighed and had the test diameter and height measured before dissection. The body components indexes were calculated. Each specimen had one gonad analyzed histologically to verify gametogenic stages. The reproductive cycle was fast and continuous showing production and spawning of gametes all the period. Morphological differences were found among diameter, height, and weight of the tests and length of Aristotle's lantern. The results of this study suggest that phenotypic plasticity and gene flow between these two populations of Arbacia lixula should be occurring. Studies on population genetics and ecology should be done before any commercial explotation of this species.

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Delmas, Philippe. "Etude des populations de Paracentrotus lividus (Lam. ) : (Echinodermata : Echinoidea) soumises à une pollution complexe en Provence Nord-occidentale : densités, structure, processus de détoxication (Zn, Cu, Pb, Cd, Fe)." Aix-Marseille 3, 1992. http://www.theses.fr/1992AIX30024.

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Dans le secteur de marseille-cortiou recevant les eaux usees de l'agglomeration marseillaise, la densite globale e macroechinodermes, conditionnee par l'echinoide p. Lividus, diminue avec la profondeur et augmente au fur et a mesure que l'on se rapproche du rejet. En 1980, le detournement sur cortiou d'un fleuve cotier: l'huveaune, a accentue la pollution de type industriel et l'hypersedimentation, les echinoides a. Lixula et s. Granularis se sont rarefies et les populations de p. Lividus ont diminue ou disparu dans les zones profondes envasees. L'etude structurale des populations de p. Lividus a montre un defaut de recrutement des 1980 et une diminution du diametre moyen du test surtout marque a 1200 m a l'ouest du rejet. Ce nanisme est lie a un deficit energetique survenant lors de la premiere maturation sexuelle, l'energie disponible devient insuffisante pour assurer les processus de detoxication, la regeneration des radioles brises, la maturation des gonades et la croissance du test que se poursuit si les oursins sont places en stabulation dans des eaux non polluees. A la suite de la mise en service, en 1987, d'une station d'epuration des eaux usees, nous avons observe, comme lors des experiences de stabulation, une diminution des concentrations en cuivre, plomb et cadmium dans les gonades et le tube digestif des p. Lividus de cortiou; par contre les concentrations en zinc ont montre des fluctuations importantes, probablement liees a l'intervention de ce metal dans les phenomenes d'edification de nouvelles plaques du test. Enfin, a la suite du rejet, par la station d'epuration, d'un excedent de chlorure ferrique, les p. Lividus ont synthetise des cristaux de fer qui s'accumulent dans le tube digestif, la glande axiale, le systeme hemal et les gonades qui s'atrophient et deviennent noiratres

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Martins, Elizabeth de Souza. "Desenvolvimento embrionário e larval de encope Emarginata (Leske, 1778) (Echinodermata: Echinoidea), e variações morfológicas interpopulacionais ao longo da costa brasileira entre 13º S e 30º S [manuscrito]/Elisabeth de Souza Martins." Rio de Janeiro:, 2008. http://repositorio.mar.mil.br/handle/ripcmb/26337.

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Tese (Doutorado) - Universidade Federal do Rio de Janeiro, Museu Nacional, 2008.
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MANCOSU, ANDREA. "Taphonomy and Palaeoecology of multi-element skeleton invertebrates: a genetic model for exceptional preservation." Doctoral thesis, Università degli Studi di Cagliari, 2013. http://hdl.handle.net/11584/266230.

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The aim of the research is to improve the understanding on the origin of fossil accumulations by investigating their taphonomic and sedimentological features and by using stratigraphic data and the autecology of the organisms forming the shell beds. A number of highly different oligospecific high dense fossil accumulations of wellpreserved, multi-element skeleton invertebrates, such as arthropods and echinoids, were studied. The first case studied concerns the Ordovician trilobite-like arthropod Tariccoia arrusensis, which is found locally within the grey siltstones of Riu Is Arrus Member (Monte Argentu Formation, Upper Ordovician), cropping out along the valley of the creek Riu Is Arrus, SE Fluminimaggiore (SW Sardinia). The locality Roia Srappas is the most distinctive whit regards to the fossil content. The facies analysis allows documenting a clastic sequence whose origin is related to turbidity currents(hyperpycnal flows) generated by a flood-dominated fluvio-deltaic system entering in lagoonal or protected shallow marine settings. Two taphofacies are recorded: tf1 consists of a high density of articulated remains, which constantly show convex down orientation, while tf2 consists exclusively of disarticulated remains randomly oriented. The preservation state and preferred orientation of arthropods in the tf1 leads to infer gentle transport by mud plumes, related to hyperpycnal flows, rapid burial and low scavenging and bioturbation. The second case focused on four clypeasteroid mass occurrences from the Lower Miocene of Sardinia, which are analyzed and compared. Two clypeasteroid assemblages were found within the Nurallao Formation (Late Oligocene-Burdigalian). The other two investigated clypeasteroid assemblages that were investigated, are found within the Calcari di Mores Formation (Late Burdigalian). These fossil echinoid deposits show a 2 low taxonomic diversity: two assemblages are dominated by the genus Amphiope while the other is dominated by Parascutella with subordinate Clypeaster. Although the four sand dollar deposits, which are the object of this study, can be assigned to a shoreface environment, there are differences in their features and origin. Three different genetic mechanisms, such as multiple in situ reworking, storm deposition and autochthonous accumulation can be inferred. The third case focused on regular echinoid and spatangoid mass accumulations, which are extremely rare in the fossil record of the Miocene of Sardinia. In the Lower Burdigalian sediments of the Marmilla Formation two monospecific regular echinoid and spatangoid mass occurrences were found. The regular echinoid assemblage consists of a dense accumulation of phymosomatid echinoid Anisophyma n.g.n.sp., which is decribed and illustrated. The other echinoid assemblage is a monospecific Brissopsis beds. The third regular echinoid mass accumulation, which is found within the Gesturi Marls (Upper Burdigalian to Langhian), is a sea urchin spine bed with rare and poorlypreserved complete tests. Although the three studied echinoid mass accumulations can be trace to a storm-dominated offshore environment, observed variations in the taphonomic and sedimentologic features are due to three different genetic mechanisms such as, rapid buried living community (obrution), time-averaged fossil bed by sediment starvation, and distal tempestite event. The studied mass accumulations allowed explaining the nature and the distribution of the fossil concentrations across a wide spectrum of environments. Nearshore depositional environments are dominated by sedimentological concentrations but can also include sedimentologically overprinted biological concentrations. In deeper water environments shell-bed development can mainly be the results of ecologic (biologic) mechanisms, shell accumulation during episodes of sediment starvation and rapid burial by storm events. The analysis of multi3 element skeleton mass accumulations showed that these fossil deposits are a useful tool for palaeoenvironment and palaeoecological reconstructions.

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Chandra, Shweta. "Roles of immunoglobulin domain proteins echinoid and friend-of-echinoid in drosophila neurogenesis." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1083161922.

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Sweijd, Neville Anthony. "The digestive mechanisms of an intertidal grazer, the sea urchin Parechinus angulosus." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005346.

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Echinoids are important grazers in the near-shore ecosystem and can significantly effect their ecology. The sea urchin Parechinus angulosus occurs inter- and subtidally along the southern African coast. Within this range it consumes an extremely wide variety of algae. Since algal cell walls have an almost species specific chemical composition, the question arises as to how it can digest the algae that it consumes. In order to investigate the digestive mechanisms employed by P. angulosus, an ultrastructural study of the gut was undertaken to characterize the tissue and identify functional regions in the gut. Ten structural and storage polysaccharides commonly found in macroalgae were used as substrates to assay the digestive polysaccharidases of the sea urchin. The enteric bacteria of the sea urchin were isolated and tested separately for polysaccharidase activity using the same substrates. The results shown that the gut of Parechinus angulosus is regionally specialized, with the foregut primarily responsible for the production of hydrolytic enzymes, while the hindgut is primarily absorptive. The occurrence of lamellar bodies, heterolysosomes, cytoplasmic blebs and paddle cilia among other characteristic features of the digestive epithelium are described and discussed. Two levels of enzyme activity are apparent. Generally the urchin could hydrolyze the reserve polysaccharides, but only partially hydrolyze the structural polysaccharides, of red and green algae. P.angulosus was unable to digest alginic acid, the main structural polysaccharide of brown algae. Mixed cultures of bacteria utilized only the reserve polysaccharides of red and green algae. Significantly, the bacteria were able to hydrolyze alginic acid. Enteric bacteria also showed agarolytic activity. Parechinus angulosus has the ability to digest red and green algae. No lysozyme activity was detected. The enteric bacteria can digest the same algal reserve polysaccharides and so may compete for carbon in the gut. However, in the case of brown algae, bacteria have a potentially important endosymbiotic role as agents of digestion. These results correspond with food preference studies which have shown that, although P.angulosus consumes the kelp Ecklonia maxima, in the western Cape, it is amongst its least preferred food species. The reasons for this are its unpalatability and the urchin's inability to digest brown algae. The digestibility of algal material can be an important factor in determining algal-herbivore interactions.

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Richardson, Cristina M. "Factors leading to cannibalism in Lytechinus variegatus (Echinodermata: Echinoidia) in the laboratory." Birmingham, Ala. : University of Alabama at Birmingham, 2010. https://www.mhsl.uab.edu/dt/2010m/richardson.pdf.

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Thesis (M.S.)--University of Alabama at Birmingham, 2010.
Title from PDF t.p. (viewed July 20, 2010). Additional advisors: Robert U. Fischer, John M. Lawrence, Ken B. Marion. Includes bibliographical references (p. 55-59).

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Jeffery, Charlotte Hannah. "Echinoid evolution across the Cretaceous-Tertiary boundary." Thesis, Imperial College London, 1997. http://hdl.handle.net/10044/1/8292.

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Squire, Gareth. "The biogeography of the Indo-West Pacific echinoids." Thesis, Queen Mary, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391824.

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Lockhart, Susanne J. "Molecular evolution, phylogenetics, and parasitism in Antarctic cidaroid echinoids /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2006. http://uclibs.org/PID/11984.

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Barras, Colin George. "The origin and early diversification of the irregular echinoids." Thesis, University of Birmingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433739.

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Farrar, Lyndsey. "Characterizing Traces of Predation and Parasitism on Fossil Echinoids." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1556793580479455.

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Miner, Benjamin G. "Evolution of phenotypic plasticity insights from echinoid larvae /." Connect to this title online, 2003. http://purl.fcla.edu/fcla/etd/UFE0001450.

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Mercurio, S. "ROLE OF STEROID HORMONES IN ECHINOID REPRODUCTIVE BIOLOGY." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/230752.

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Echinoid reproductive cycle has been extensively studied in several species but the mechanisms regulating gametogenesis processes are still scarcely understood. Apart from environmental factors, different research have suggested a steroid role in gonad maturation and growth. Particularly, in echinoderms steroid involvement in reproduction has been suggested by both studies on seasonal changes of steroid levels during the gonadal cycle and experiments of hormone administration. Nevertheless, the steroid function in echinoid reproductive processes has not been clearly identified, probably due to the low number of studies and the big variability of results reported. Thus, the main aim of this research project was to shed light on echinoid endocrinology and, in particular, to clarify the involvement of sex-steroid hormones in sea urchin reproductive biology. This was achieved employing both in vivo and in vitro approaches. First of all, considering the lack of studies on the development of effective cell cultures from echinoderm gonads, primary cell cultures from ovaries of the edible sea urchin Paracentrotus lividus were developed. Ovary cell phenotypes, present in culture, were identified and characterized by different microscopic techniques. Although cell cultures could be produced from ovaries at all stages of maturation, the cells appeared healthier and viable, displaying a higher survival rate, when ovaries at early stages of gametogenesis were used. In terms of culture medium, ovarian cells were successfully cultured in modified Leibovitz-15 medium, whereas poor results were obtained in Minimum Essential Medium Eagle and Medium 199. Different substrates were tested but ovarian cells completely adhered only on poly-L-lysine. To improve in vitro conditions and stimulate cell proliferation different serum-supplements were tested. Fetal Calf Serum and an originally developed Pluteus Extract resulted to be detrimental to cell survival, apparently accelerating processes of cell death. In contrast, cells cultured with sea urchin Egg Extract appeared larger and healthier, displaying an increased longevity that allowed to maintain them for up to 1 month. Overall this study provides new experimental bases and procedures for producing successfully long-term primary cell cultures from sea urchin ovaries, providing a simple and versatile experimental tool for research in echinoderm reproductive biology. Subsequently, in vivo and in vitro experiments, specifically addressed to determine possible 17β-estradiol (E2) and testosterone (T) involvement in echinoid reproduction, were performed. An in vivo long-term experiment of steroid dietary administration was performed in adult specimens of P. lividus. The experimental plan was specifically designed in order to reduce individual variability and synchronize the experimental animals at the same starting maturative condition. We analysed and compared different reproductive parameters (Gonad Index, Maturative Index and maturative stages distribution) in 4 experimental groups: control group (CTL), E2 and T groups fed with pellets containing respectively 17β-estradiol and testosterone, and E2-4 weeks group fed with control pellets for the first 4 weeks and then treated with 17β-estradiol. This latter was chosen in order to verify the existence of a specific E2-sensitive gametogenic stage, as proposed in different asteroid species. Possible steroid effects on P. lividus female reproduction was also investigated with an in vitro approach. Cells, isolated by ovaries in the same maturative conditions considered in the in vivo experiments, were cultured in presence of E2 and T physiological concentrations for 2 weeks. Effects on ovarian cell morphology and behaviour were investigated. In addition, steroid regulation of the Major Yolk Protein (MYP) expression was analyzed 24 and 48 hours after E2 and T exposure. According to our results, E2 and T do not markedly influence echinoid gonad maturation and, particularly, they do not promote gamete maturation. Hormonal dietary administration did not induce striking variations in the considered reproductive parameters and no effect was observed also when males and females were analyzed separately. In addition, no specific maturative stage sensitive to E2 was found, suggesting the existence of different hormonal mechanisms in asteroids and echinoids. Similar considerations could be reported taking into account the in vitro experiments. E2 and T exposure did not affect ovarian cell size and behaviour nor MYP expression. The obtained results suggest that these hormones are not directly involved in either gamete maturation, as demonstrated for vertebrates, or in vitellogenesis processes, as reported for several asteroid species. However a possible involvement of steroids in echinoid physiology cannot be completely excluded and their role in the regulation of lipid metabolism and protein synthesis during the different reproductive stages should be strongly considered as suggested by several authors. Further specific research on steroid hormone mode of action, physiological function and metabolism are therefore needed to completely understand echinoid reproduction and endocrinology.

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Robertson-Andersson, Deborah. "The echinoid Parechinus angulosus and its association with other invertebrates." Bachelor's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/26024.

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Echinoids are recognized as important components of temperate kelp forests because of the impact that they have by grazing. The provision of shelter by some echinoid species for both juvenile conspecifics and for other species of echinoids has been widely documented. The behaviour is thought to be important in the survival of these species. The role of echinoids as protective "nurseries" for several types of marine animals has also been suggested. Adult echinoids are supported 1 - 2 cm above the substrate by the oral spines, this leaves a gap under the echinoid where other organisms can shelter. This paper examines firstly what types of organisms associate with the echinoid Parechinus angulosus and the degree to which they display tight relationships vs. chance associations. Secondly, it explores how much selectivity of the echinoids was involved when compared to other physical shelters and open substrate. This was done by comparing differences in the species associated with level, flat rocks covered with crustose corallines; the holdfasts of Ecklonia maxima; sand, and under echinoids. The study was done at four sites in False Bay, Cape Peninsula, South Africa. Samples were collected on each habitat type by placing a bottle over the substrate and scraping the sample into the bottle. The organisms in each sample were identified under a microscope and counted. The available habitat at each site was survey by divers swimming 6 am transects and noting the cover of a particular habitat falling under the tape measure. The total number of species and organisms for each site were compared using one-way and two-way ANOVA's on untransformed data. The availability of different habitat types at each site was compared, using one-way fixed-effects ANOVA. Results showed that there was no significant difference between habitat availability at the different sites. Results of the two-way ANOVA's comparing site and habitat for individual species showed that the amphipod Paramoera capensis only occurred in significant numbers at one echinoid site. The fact that 65 % of this species had a colour variation that matched the echinoid, implied that the amphipod gains protection from predators by being associated with subtidal echinoids. This relationship is not obligate as this amphipod was found in other habitats. The echinoid Parechinus angulosus appears to have a dual habitat preference with juveniles less than 1 O mm in diameter sheltering beneath adult conspecifics and juveniles greater than 1 o mm in diameter sheltering in kelp holdfasts. The amphipod Hyale grandicomis occurred in significant numbers associated with echinoids and had a habitat preference for echinoids, suggesting that it has an important relationship with subtidal echinoids. The amphipod is a known grazer of macroalgae and thus it is possible that the amphipod gets access to a food resource in the form of drift kelp, which is trapped by the echinoid. If this is the case then the amphipod would also be gaining protection from predators by being associated with the echinoid as the amount of time it is exposed while foraging is minimal.

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Soars, Natalie Anne. "Habitat soundscapes and sound production by tropical and temperate sea urchins and the swimming behaviour of their larvae." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13923.

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The distribution, abundance and behaviour of soniferous organisms influence the spatial variability of underwater noise characteristics or ‘soundscape’. In this way, the soundscape provides useful information on habitat and assemblages that enables navigation in larvae and can be used for environmental assessment and monitoring. Despite the ecological importance of sea urchins and evidence they produce sound of their sound, knowledge gaps remain regarding the role of adult and larval sea urchins in acoustic ecology. In this thesis the sounds produced by 3 temperate and 3 tropical species of sea urchins were characterised. The soundscape of sea urchin habitat from important ecological systems (sea grass, temperate rocky reef, coral reef) in eastern Australia were also characterised. The sea urchins made a ‘crunching’ sound when feeding that was commonly produced around dawn, dusk or midnight. This sound ranged from 2-22 kHz with highest intensity from 2-8 kHz. Centrostephanus rodgersii appeared to contribute to a diurnal chorus between 2-8 kHz in the ‘barrens’ habitat of Jervis Bay, NSW. Analysis of the 5000 Hz 1/3rd octave band revealed a difference between barrens sites of up to 10 dB re 1 µPa2. A similar difference was found between two coral reef habitats recorded at One Tree Island, QLD. Arm angle development reflects swimming ability in sea urchin larvae and so was documented for two-armed and multi-armed larvae forms to characterise their swimming biology. In a behavioural study of early and settlement stage larvae of H. tuberculata and C. rodgersii, early stage larvae exhibited signs of negative phototaxis swimming down during the day, suggesting that they exhibit diurnal migration in the field. However, larvae did not modify this swimming behaviour in response to a reef noise. This research will enable detection of sea urchin sounds in ambient noise recordings and provides insight into the impacts of sea urchin populations on the marine soundscape.

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Rendina, Francesco. "Effects of acute temperature increase on performance and survival of Caribbean echinoids." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10050/.

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Climate change is occurring at a faster rate than in the past, with an expected increase of mean sea surface temperatures up to 4.8°C by the end of this century. The actual capabilities of marine invertebrates to adapt to these rapid changes has still to be understood. Adult echinoids play a crucial role in the tropical ecosystems where they live. Despite their role, few studies about the effect of temperature increase on their viability have been reported in literature. This thesis work reports a first systematic study on several Caribbean echinoids about their tolerance to temperature rise in the context of global warming. The research - carried out at the Bocas del Toro Station of the Smithsonian Tropical Research Institute, in Panama - focalized on the 6 sea urchins Lytechinus variegatus, L. williamsi, Echinometra lucunter, E. viridis, Tripneustes ventricosus and Eucidaris tribuloides, and the 2 sand dollars Clypeaster rosaceus and C. subdepressus. Mortality and neuromuscular well-being indicators - such as righting response, covering behaviour, adhesion to the substrate, spine and tube feet movements - have been analysed in the temperature range 28-38°C. The righting time RT (i.e., the time necessary for the animal to right itself completely after inversion) measured in the 6 sea urchin species, demonstrated a clearly dependence on the water temperature. The experiments allowed to determine the “thermal safety margin” (TSM) of each species. Echinometra lucunter and E. viridis resulted the most tolerant species to high temperatures with a TSM of 5.5°C, while T. ventricosus was the most vulnerable with a TSM of only 3°C. The study assessed that all the species already live at temperatures close to their upper thermal limit. Their TSMs are comparable to the predicted temperature increase by 2100. In absence of acclimatization to such temperature change, these species could experience severe die-offs, with important consequences for tropical marine ecosystems.

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Lapic, Whitney Alexandra. "An Asynchronous Mesozoic Marine Revolution: Drilling Versus Durophagy in Post-Paleozoic Echinoids." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1619187876334553.

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Poddubiuk, Robert Henry. "Sedimentology, echinoid palaeoecology and palaeobiogeography of Oligo-Miocene Eastern Caribbean limestones." Thesis, Royal Holloway, University of London, 1987. http://repository.royalholloway.ac.uk/items/0443b1ea-4dd5-4573-af4c-01f218b7154d/1/.

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The Upper Oligocene Antigua Formation comprises a rapidly deposited sequence of limestones developed in an oceanic-arc setting immediately before cessation of subaerial volcanism. Ten sedimentary facies are recognized within it, ranging in depositional environment from shallow sublittoral to deep bank-slope. Their present outcrop patterns largely reflect original lateral facies variation across the ancient bank margin. The latter was mainly depositional in character, with bank-top often passing rather gradually into the upper bank-slope. Although a similar range and number of sedimentary facies are recognized within the Lower Miocene Anguilla Formation, bank-edge reefs are better-developed and the upper bank-slope shows evidence of sediment bypassing. Palaeoautecological and palaeosynecological studies of echinoid faunas can provide useful information on palaeoenvironment. Twenty genera and thirty-two species of echinoids are represented in the Antigua and Anguilla Formations. Of the species, five are entirely new, seven more are described for the first time from the Lesser Antilles, and a further three have their known ranges extended within the region. Of the genera, four were previously unrecorded as fossils from the Lesser Antilles, one, Irenechinus, being described for the first time outside Australasia. Twelve genera have their diagnoses and/or synonymies significantly modified from previously accepted usage. A new subgenus is erected for the earliest-known Caribbean representative of Tripneustes. Sedimentological evidence of hurricane activity within the Antigua and Anguilla Formations indicates that mid-Cenozoic sea-surface temperatures in the equatorial Atlantic were similar to those of the present day. Cenozoic echinoid biogeography supports an arc-migration model for the origin of the Caribbean Plate, indicates that speeds of shallow marine currents have increased during the Neogene (with the most significant changes affecting eastward Undercurrents), and suggests that a proto-Gulf Stream was in operation by Eocene times.

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Perricone, Valentina. "Temperature effects on larval growth and survival in five species of Caribbean Echinoids." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10049/.

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Under the global change scenario, the possible effects of ocean warming were investigated on the larvae of five species of Caribbean Echinoids: Echinometra lucunter, Echinometra viridis, Clypeaster rosaceus, Tripneustes ventricosus and Lytechinus williamsi. Their thermal tolerance was evaluated rearing them for six days under different temperature regimes (26, 28, 30, 32, 34, 36°C). The larval sensitivity to the treatments was evaluated on the base of survival and growth. The rearing at higher temperatures has revealed a great suffering state of the larvae by inducing both reduction of live larvae and abnormality in their development. The extent of impact of the treatments varied from species to species, evidencing different levels of thermal tolerance. Anyway, higher temperature treatments have shown a general lethal threshold at about 34°C for most of the species. As an exception, the lethal threshold of Echinometra species was 36°C, few larvae of which being still capable of survive at the temperature of 34°C. The studies have also analyzed the effect of water warming on the larvae growth in terms of size and symmetry. The results put in evidence the presence of a critical upper temperature (about 32°C) at which the larvae of all species reveal a great suffering state that translates in the reduction of size (i.e., of body, stomach and postero-dorsal arm) and abnormalities (i.e., strong difference in the lengths of the two postero-dorsal arms). As sea surface temperatures are predicted to increase of 4-5°C by 2100, the high percentage of abnormal larvae and their scarce survival observed at 32- 34°C treatments indicate that the early stages of these species could be affected by future global warming.

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Campos-Creasey, Lucia de Siqueira. "A study of the feeding biology of deep-sea echinoids from the North Atlantic." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316314.

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Williamson, Lauren Elizabeth. "A Morphometric Analysis of the Highly Variable Clypeasteroid, Periarchus lyelli." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1247181599.

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Dissertations / Theses on the topic 'Echinoidea'

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