Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-18T21:48:47Z No. of bitstreams: 1 541875.pdf: 4255763 bytes, checksum: a22edc985359ae7ee17955cf71b2fdca (MD5) / Made available in DSpace on 2018-01-18T21:48:47Z (GMT). No. of bitstreams: 1 541875.pdf: 4255763 bytes, checksum: a22edc985359ae7ee17955cf71b2fdca (MD5) Previous issue date: 2001-04-11 / CAPES / 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.

Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-19T13:47:16Z No. of bitstreams: 1 541855.pdf: 3191717 bytes, checksum: 910c30f23e3c29b3f77da2c853160065 (MD5) / Made available in DSpace on 2018-01-19T13:47:16Z (GMT). No. of bitstreams: 1 541855.pdf: 3191717 bytes, checksum: 910c30f23e3c29b3f77da2c853160065 (MD5) Previous issue date: 2001-03-23 / CAPES / 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.

Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-19T13:52:39Z No. of bitstreams: 1 542893.pdf: 6816025 bytes, checksum: 6e417b1811f0c1b94a6b963c3e983658 (MD5) / Made available in DSpace on 2018-01-19T13:52:39Z (GMT). No. of bitstreams: 1 542893.pdf: 6816025 bytes, checksum: 6e417b1811f0c1b94a6b963c3e983658 (MD5) Previous issue date: 2001-04-07 / A reprodução sexuada em Asteroidea envolve a produção de gametas. fertilização externa e o desenvolvimento de fases larvais. Uma grande variedade de estratégias reprodutivas pode ser observada nos asteróides da família Asterinidae, sendo observadas espécies que produzem ovos pequenos e larvas planctotróficas, de longa duração na coluna d'água, espécies que produzem ovos grandes e larvas lecitotróficas, de curta duração na coluna d'água e até mesmo espécies vivíparas. Muito pouco se sabe a respeito dos aspectos reprodutivos de Asteroidea no litoral brasileiro. No presente estudo, serão verificaclos e descritos os aspectos reprodutivos de A. stellifera em duas populações na região de Cabo Frio, incluindo o ciclo gonadal, a gametogênese e o desenvolvimento larval. A primeira população está na região entre-marés da Ilha do Japonês, junto às gramíneas marinhas. A outra população situa-se no infralitoral rochoso das Prainhas do Pontal, em Arraial do Cabo. O desenvolvimento larval foi descrito por intermédio de cultivo em laboratório. O ciclo reprodutivo foi estudado em intervalos mensais utilizando-se índice dos órgãos e exame histológico das gônadas. A. stellifera apresentou um desenvolvimento planctotrófico típico em asteróides, com dois estágios larvais sucessivos, uma larva bipinária e outra braquiolária. Foi verificado um padrão reprodutivo anual, com picos de desenvolvimento gonadal em agosto e setembro, nas duas populações. A periodicidade dos eventos reprodutivos foi idêntica nas duas populações, mas diferenças no índice gonadal (IG) e no índice dos cecos pilóricos (ICP) foram observadas. Na população do infralitoral rochoso os valores de IG foram maiores e foi observada uma menor variação nos valores de ICP. Foi observada uma relação inversa entre os valores de IG e ICP sendo que na população da região entre-marés esta relação foi mais evidente. As diferenças observadas podem estar associadas a fatores ambientais, como hidrodinamismo e disponibilidade alimentar. / The development and reproductive cycle of Asterina stellifera were studied from amples taken from populations in two distinct habitats from Cabo Frio. One is an intertidal seagrass flat at Japonês lsland ( 1994-1995); the second is a sublittoral rocky-shore at Pontal Beaches ( 1999-2000). Development pattern was described based on laboratory cultures. Reproductive cycle was studied at monthly intervals by organ indices and histological examinations of gonads. A. stellifera has a typical planktotrophic development with bipinnaria and brachiolaria stages. The periodicity of the annual reproductive cycle was similar for both populations, but the gonad índex (Gl) was higher and the pyloric caeca index (PCI) had less variation in the rocky-shore population. The Gl and PCI had an inverse relationship in both populations, but it was greater in the seagrass-flat population. Environmental factors like hydrodynamics and food availability are the most probable mechanisms for these differences.

De nombreux organismes marins précipitent des squelettes en calcite magnésienne. Depuis près d’un siècle, il est connu que les concentrations en magnésium de ces squelettes sont influencées par les conditions environnementales, telle la température, régnant au moment de leur dépôt. Dans le contexte actuel de changement climatique, cette propriété a promu l’usage de plusieurs taxons en tant qu’archive naturelle des conditions environnementales du passé. Cependant, les squelettes d’espèces sympatriques, voire d’individus de la même espèce, peuvent présenter des concentrations en magnésium très différentes, attestant de l’influence de facteurs biologiques sur la détermination de la concentration squelettique en cet élément. Une parfaite compréhension des mécanismes d’incorporation du magnésium dans les squelettes est donc requise pour valider l’usage de ce paléotraceur. De plus, la solubilité des calcites augmentant avec leur concentration en magnésium, l’incorporation de cet élément conditionne en partie la stabilité des squelettes calcitiques dans un océan en cours d’acidification.<p>Le présent travail contribue à l’étude des différents facteurs, tant environnementaux que physiologiques et minéralogiques, susceptibles d’affecter l’incorporation du magnésium dans les squelettes en calcite de trois taxons présentant des concentrations en cet élément particulièrement élevées, une éponge hypercalcifiée, Petrobiona massiliana, et deux échinodermes, Paracentrotus lividus et Asterias rubens.<p>Dans une première partie, les effets de plusieurs facteurs environnementaux ont été étudiés, en milieu naturel dans le cas de l’éponge, étant donné son incapacité à survivre en aquarium, et en conditions contrôlées d’aquarium dans le cas des deux échinodermes. Une influence environnementale prépondérante de la température sur la concentration en magnésium squelettique a été mise en évidence dans les 3 modèles biologiques étudiés. Une fois les facteurs génétiques (espèce) et structurels (élément squelettique) fixés, une relation positive liant la température à la concentration en magnésium squelettique a été caractérisée en milieu naturel chez l’éponge hypercalcifiée P. massiliana et en conditions contrôlées chez l’oursin P. lividus. Chez ce dernier, cette relation, non linéaire, se stabilise aux plus hautes températures envisagées, probablement suite à la saturation d’un processus biologique intervenant dans l’incorporation de cet élément. La salinité, un autre facteur environnemental majeur en milieu marin, influence elle aussi positivement la concentration en magnésium dans le squelette de l’étoile de mer A. rubens. A nouveau, il est proposé que cette influence de l’environnement soit modulée par un processus biologique: chez les échinodermes, la concentration en magnésium, contrairement à celle du calcium, n’est pas régulée dans le liquide coelomique. Elle est donc directement influencée par la salinité, et affecte probablement la concentration en cet élément dans le squelette formé. La diffusion depuis l’eau de mer jusqu’au site de calcification par l’intermédiaire des fluides internes a en effet été suggérée sur base du fait que le rapport Mg/Ca de l’eau de mer influence celui des squelettes calcaires<p>Une fois l’influence, directe ou indirecte, des facteurs environnementaux exclue, 44% de la variabilité du rapport Mg/Ca du squelette des échinodermes restent à expliquer. Les expériences de croissance d’échinodermes réalisées en conditions contrôlées indiquent que ce rapport est indépendant de la vitesse de croissance dans ce groupe, contrairement aux hypothèses émises dans la littérature.<p>Dans la seconde partie, la modulation des facteurs minéralogiques par les facteurs biologiques a été investiguée. Pour ce faire, d’une part, les interactions entre rapport Mg/Ca en solution et matrice organique de minéralisation ont été étudiées dans un modèle in vitro. D’autre part, les relations entre soufre et magnésium dans le squelette ont été décryptées.<p>Le rapport Mg/Ca de la solution de précipitation a une influence prépondérante sur la concentration en magnésium du carbonate de calcium précipité in vitro, attestant de l’importance de la régulation de la composition du fluide de calcification et des mécanismes de transport la contrôlant. Deux mécanismes biologiques complémentaires permettent de favoriser l’incorporation, dans les calcites biogéniques, de quantités de magnésium largement supérieures à celles observées dans les calcites inorganiques, et ce, malgré la forte hydratation de ce cation :l’intervention d’agents chélateurs du magnésium et le passage par une phase de carbonate de calcium amorphe (CCA). Les molécules de la matrice organique de minéralisation jouent entre autres le rôle de chélateur du magnésium, réduisant son état d’hydratation et facilitant ainsi son incorporation dans le minéral. Un rôle similaire a été suggéré pour les sulfates en solution, au vu de la corrélation observée dans ce travail entre les rapports Mg/Ca et S/Ca dans la phase minérale des calcites biogéniques étudiées. La matrice organique affecte elle aussi la concentration en magnésium dans le cristal, probablement via la stabilisation de la phase de CCA nécessaire à l’incorporation de concentrations élevées de cet élément: ainsi, les macromolécules de la matrice organique du test d’oursin induisent in vitro la formation de calcites plus riches en magnésium que celles formées en présence de matrice de piquant, un résultat concordant avec le fait que, in vivo, le test contient des concentrations en magnésium plus élevées que les piquants.<p>Cette thèse de doctorat a donc soulevé l’importance des effets biologiques dans la détermination du rapport Mg/Ca dans les calcites biogéniques. Les résultats obtenus montrent que le décryptage des mécanismes impliqués dans l’incorporation du magnésium se doit de considérer la phase amorphe transitoire qui précède la cristallisation. Des effets environnementaux affectent eux aussi la concentration squelettique en magnésium, mais nos résultats suggèrent qu’ils agissent au travers d’une modulation des effets biologiques, et non par une influence thermodynamique directe. Cette hypothèse, si elle est confirmée, impose la plus grande prudence lors de l’utilisation des squelettes en calcite en tant que paléotraceurs.<p><p><p>SUMMARY<p>The magnesium concentration in calcite skeletons produced by marine invertebrates is known to be dependent on several environmental parameters, including temperature, salinity and seawater Mg/Ca ratio. This property prompted the use of this concentration as a proxy of the considered parameters. However, skeletal magnesium contents in sympatric species and even in individuals of the same species may be rather different. These inter and intra-individual variabilities indicate that biological factors also affect magnesium incorporation into biogenic calcites. Magnesium incorporation mechanisms are still unknown in calcifying invertebrates, a fact that questions the validity of this element as a paleoproxy. Moreover, higher magnesium contents increase calcite solubility and could therefore worsen the case of calcifying organisms facing ocean acidification linked to global change.<p>The present thesis is a contribution to the study of the environmental, biological and mineralogical factors affecting magnesium incorporation into the calcitic skeletons of 3 taxa, i.e. one hypercalcified sponge, Petrobiona massiliana, and two echinoderms, Paracentrotus lividus and Asterias rubens.<p>The first part of this work was dedicated to the study of several environmental factors affecting the magnesium concentration in the calcite skeleton of the 3 studied organisms. Consequently to its low survival in aquarium, the sponge was studied using field specimens collected along an environmental gradient. Echinoderms were grown in controlled conditions in aquarium. Once the genetic (species) and structural (skeletal element) factors were fixed, skeletal magnesium concentration was positively related to temperature in the 3 studied species. The Mg/Ca ratio of the test of aquarium-grown P. lividus increased with temperature until a plateau which was probably due to the saturation of a biological process involved in magnesium incorporation. A positive effect of salinity, an other major environmental parameter, on skeletal Mg/Ca was demonstrated in aquarium-grown A. rubens. This influence can also be linked to a biological process: contrary to magnesium, calcium concentration is controlled in the coelomic fluid, from which ions probably diffuse through the living tissues to the calcification site. Thus, the observed positive relation can be explained by the fact that a salinity increase raises the coelomic Mg/Ca ratio, which, according to previous studies, affected the Mg/Ca ratio of the precipitated skeleton.<p>In addition to the reported environmental influences, 44% of the skeletal Mg/Ca ratio variation remained unexplained in echinoderms. The absence of growth rate effect on magnesium incorporation into the echinoderm skeleton was demonstrated in aquarium experiments, contrary to previous literature statements. Other biological factors must therefore affect the incorporation of this element.<p>In the second part of this work, the modulation of mineralogical factors by biological factors was investigated. The interaction between Mg/Ca ratio in the precipitation solution and organic matrix was studied in an in vitro precipitation experiment. In addition, the relation between skeletal Mg/Ca and S/Ca ratios was investigated.<p>A major influence of the precipitation solution Mg/Ca ratio on the magnesium concentration of in vitro precipitated minerals was evidenced, highlighting the importance of transport mechanisms which determine the composition of the calcifying solution. The<p>higher magnesium concentrations presented in some biogenic calcites in comparison to inorganic calcites can be attributed to the action of chelating molecules and to the transition trough an amorphous phase. The strong tendency of magnesium towards hydration can be overcome by the involvement of molecules that can function as magnesium chelators and, therefore, favour the formation of calcite with a high magnesium content. Organic matrix macromolecules have been suggested to proceed as magnesium chelators, reducing the hydration of this ion and facilitating its incorporation into calcite. A similar function was suggested for sulphates that were measured in the echinoderm skeleton. This would explain the positive correlation between skeletal Mg/Ca and S/Ca ratios observed in the studied species. Organic matrix macromolecules also increased the magnesium concentration of minerals precipitated in vitro, probably stabilizing the transient phase of amorphous calcium carbonate, which can incorporate high quantities of magnesium in its structure. The enhancement of magnesium incorporation was more pronounced with the organic matrix extracted from the test of sea urchin than with that extracted from their spines. This result was in agreement with the in vivo skeletal Mg/Ca ratios in P. lividus skeleton that were higher in the test than in the spines.<p>This study demonstrated the importance of the biological effects in the determination of Mg/Ca ratios in biogenic calcites. According to the suggested hypotheses, the understanding of mechanisms involved in magnesium incorporation should take the transient amorphous phase into account. Magnesium concentration in biogenic calcite was also affected by environmental parameters, but these influences could proceed through the indirect modulation of biological rather than a direct thermodynamic control. This hypothesis, if proved correct, would have deep implications for the use of magnesium in calcite skeletons as a paleoproxy. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Orientador: Michela Borges / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T05:03:51Z (GMT). No. of bitstreams: 1 Alitto_RenataAparecidadosSantos_M.pdf: 8727741 bytes, checksum: cec55277cd7fcd22f90e5b2522a2a3e3 (MD5) Previous issue date: 2015 / Resumo: Com o propósito de estudar a biodiversidade dos Echinodermata da Baía do Araçá, São Sebastião (SP), foi analisado o material procedente do Projeto Biota/FAPESP- "Biodiversidade e funcionamento de um ecossistema costeiro subtropical: subsídios para gestão integrada", Proc. nº 2011/50317-5. Para avaliação da diversidade e densidade desses organismos foram realizados: (i) inventário dos Echinodermata; (ii) estudos taxonômicos morfológicos com descrições detalhadas e discussões específicas para Ophiuroidea, incluindo ilustrações e fotomicrografias das espécies e ampliação das descrições já existentes e (iii) estudo dos fatores que influenciam a riqueza e abundância desses animais em microescala. Os equinodermos foram amostrados na região entremarés até 23 m de profundidade, costões rochosos, e como fauna associada a esponjas. Dos 863 exemplares coletados, foram identificadas quatro classes, 13 famílias, 19 gêneros e 25 espécies, o que corresponde a 8,3 % dos equinodermos registrados para o litoral brasileiro. A classe Ophiuroidea foi a mais diversa com 16 espécies e duas delas representam novos registros para a Baía: Amphiura kinbergi e Ophiothela danae. Para as espécies de ofiuróides, foi realizado um estudo taxonômico mais aprofundado com descrições da morfologia externa e interna (ossículos braquiais), o que enriqueceu as descrições já existentes. A maior riqueza e abundância deste grupo foi verificada no infralitoral quando coletado com draga. Amphiuridae e Ophiactidae foram as famílias mais representativas e corresponderam a aproximadamente 80 % do total de ofiuróides amostrado. Os resultados obtidos com esse trabalho contribuirão de forma consistente para o conhecimento da biodiversidade dos equinodermos no Estado de São Paulo, será a base para futuros monitoramentos sobre o impacto das atividades humanas na baía e seu entorno e contribuirá para implementações de ações de conservação deste rico ambiente / Abstract: The aim of the present work is to study the biodiversity of Echinodermata from Araçá Bay, São Sebastião (SP). We analyzed the material from Biota Project / FAPESP - "Biodiversity and functioning of a subtropical coastal ecosystem: a contribution to integrated management", Proc. No 2011 / 50317-5. Diversity and density avaliations of these organisms were performed to: (i) build an inventory of Echinodermata; (ii) morphological taxonomic studies with detailed descriptions and specific discussions to Ophiuroidea, including illustrations and photomicrographs of species and expansion of existing descriptions and (iii) study the factors that influence the richness and abundance in microscale. The echinoderms were sampled in the intertidal zone to 23 m deep, rocky shores, and as associated fauna of sponges. The 863 specimens collected were classified into four classes, 13 families, 19 genera and 25 species, corresponding to 8.3 % of echinoderms registered for the Brazilian coast. The Ophiuroidea was the most diverse with 16, with two being are new records for the Araçá Bay: Amphiura kinbergi and Ophiothela danae. For species of brittle stars, there was a further taxonomic study with descriptions of external and internal morphology (arm ossicles), that enriched the existing descriptions. The highest richness and diversity of this group was observed in infralitoral when collected with a dredge. Amphiuridae and Ophiactidae were the most representative brittle stars families and accounted for approximately 80 % of brittle stars sampled. The results of this work will contribute consistently to the knowledge of the echinoderms diversity in São Paulo, will be the basis for future monitoring of the human activities impact on the bay will contribute to this rich conservation actions implementations environment / Mestrado / Biodiversidade Animal / Mestra em Biologia Animal

Crinoids are the most primitive living members of the Phylum Echinodermata. Though still present in reduced numbers today, crinoids were the dominant echinoderms from the Ordovician to the Permian. The crinoid body plan consists of three major regions, the column, the calyx, and the arms. Each region serves important functions in crinoids. The column raises the rest of the body into the water column for more efficient feeding. The calyx contains the visceral mass and mouth. Arms extend out from the top of the calyx to trap microorgansisms and suspended organic particles in the water column. A re-evaluation of these functional units is undertaken to understand the importance of various structures and to obtain discrete characters for use in a cladistic analysis. The relationship of crinoid crown groups has been an active area of research for the past couple of decades. With each proposed phylogenetic relationship, a new interpretation of thecal plate homology has been proposed. Here each study is re-examined in the light of new data. A review of functional morphology indicates a dual-reference system to be the most supported interpretation of plate homology. The two reference points in this system are the stem-cup and the cup-arm junctions, at the top and bottom of the calyx. The difference between a two-circlet and three-circlet crinoid is the presence or absence of the middle (basal) circlet. A new cladistic analysis is presented, with the topology of trees obtained giving support for the retention of Paleozoic crinoid stem and crown groups. Crinoids appear abruptly in the fossil record. Questions pertaining to origins and ancestral stock abound. A biogeography study is employed to look at the distribution of crinoids from the Early to Middle Ordovician. Locality information, combined with an understanding of the movement of major plates, paleoclimate data, an understanding of larval distribution, and a review of similar studies carried out on different taxa, gives insight into possible radiation and dispersal patterns of crinoids from the first half of the Ordovician. / text

The key character separating the dendrochirotid families Sclerodactylidae (sensu Pawson & Fell, 1965) and the Phyllophoridae (sensu Pawson & Fell, 1965), i.e. entire or undivided radial processes to the calcareous ring in the former and sub-divided processes in the latter, is unjustified since most sclerodactylid species also have subdivided processes. It is here assumed that the basis of elevating the subfamily Sclerodactylinae Panning to family level was established on a misinterpretation or mistranslation of the original diagnosis of this subfamily or a lapsus calumni meaning “plates” instead of “processes”. Panning (1949) categorically states that the processes in the Sclerodactylinae are composed of 3–4 large pieces of calcite and only as an exception they are unbroken. Since Pawson & Fell gave no other distinction between the Sclerodactylidae and the Phyllophoridae, the former is here considered an invalid taxon and its three current subfamilies (Sclerodactylinae, Sclerothyoninae Thandar and Cladolabinae Heding & Panning) are re-assigned to the Phyllophoridae. This family now includes six subfamilies: Cladolabinae, Phyllophorinae Östergren, Sclerodactylinae, Sclerothyoninae, Semperiellinae Heding & Panning and Thyoninae Panning. The diagnosis of the Sclerodactylinae, restricted by Thandar (1989), is now modified to include also those forms whose radial and interradial plates may be slightly sub-divided but still form a short tube. Of the eleven genera placed within this subfamily subsequent to its erection, only ten of these remain. Neothyone Deichmann is a preoccupied name for which Lisacucumis is here proposed as a replacement. Thandar’s (1989) diagnosis of the Thyoninae is here accepted, however, the genus Thorsonia Heding is transferred to the Sclerodactylinae. Of the 66 nominal species which currently stand in the “supergenus” Thyone Jaeger, 10 are transferred to Havelockia Pearson within the Sclerodactylinae, while one species is regarded as a synonym of H. herdmani Pearson. In addition, six species are transferred to Stolus Selenka within the Thyoninae. Finally, three species are transferred to Sclerothyoninae, two within Sclerothyone Thandar and one within Temparena Thandar. Two species show an uncertain affinity to Thyone and are temporally removed from the genus. Furthermore, two species currently classified within Havelockia are transferred to Thyone. The now remaining 46 species are separated into seven groups based on the composition of their introvert deposits: tables only (8 spp.), rosettes only (5 spp.), tables and rosettes (21 spp.), tables and plates/?reduced tables (2 spp.), rosettes and plates/?reduced tables (3 spp.), plates only (2 spp.), or introvert deposits absent or unknown (5 spp.). Regrettably, no other character could be used in conjunction with the above to suggest at least sub-generic levels. Within the genus Havelockia, Cucumaria redimita Sluiter indicates an affinity with Pentamera Ayres. It is here transferred to this genus within the Thyoninae. Havelockia, now containing 17 species, is also revised. Keys, diagnoses and figures are provided for all nominal species now included in Thyone and Havelockia. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.

Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-12T17:19:13Z No. of bitstreams: 1 551959.pdf: 4388266 bytes, checksum: d7cab9b2a04f22084032633624bd216c (MD5) / Made available in DSpace on 2018-01-12T17:19:13Z (GMT). No. of bitstreams: 1 551959.pdf: 4388266 bytes, checksum: d7cab9b2a04f22084032633624bd216c (MD5) Previous issue date: 2002-01-08 / No presente estudo indivíduos de Echinaster (Othilia) brasiliensis foram coletados mensalmente na Praia de João Fernandes, Búzios, RJ, no período de agosto de 1999 a dezembro de 2000, a fim de verificar e descrever o ciclo reprodutivo e a estratégia reprodutiva da espécie. Para o estudo do ciclo reprodutivo usou-se o índice das gônadas e a análise histológica das gônadas. E. (O.) brasiliensis apresentou uma reprodução contínua. Uma assincronia no desenvolvimento gonadal dos indivíduos da população foi detectada com base na análise histológica das gônadas. A análise das frequências de tamanho dos ovócitos indicou que as classes de 60 μm e 160 μm foram as mais representativas. Ovócitos de vários tamanhos ocorreram concomitantemente em diferentes fêmeas ao longo do período estudado. A ausência de ovários vazios e a variação no tamanho dos ovócitos sugerem uma ovogênese contínua em cada indivíduo. Os cecos pilóricos não apresentaram um ciclo anual. Não foi encontrada qualquer relação inversa entre o índice gonadal e o índice dos cecos pilóricos. / ln the present study specimens of Echinaster (Othilia) brasiliensis were collected monthly at João Fernandes Beach, Búzios, Brazil, from August 1999 to December 2000. Reproductive cycle was studied using gonad index and histological analysis of gonads. E. (O.) brasiliensis exhibited a continuous reproduction. Histological analysis of gonads showed asynchrony in gametogenesis among the individuals of this population. Small and mesovitellogenic oocytes (60-160μm) were the dominant size-class in all samples. Several size classes of oocytes were found together in may ovaries along the studied period. No spent ovaries were found. Probably, the ovaries were not empty for the recovering. The pyloric caeca did not show an annual cycle. An inverse relationship between gonad and pyloric caeca indices was not evident.

No description available.

The Cretaceous was a time of many changes on the earth s surface that contributed to develop a rich diversity of organisms. The Potiguar Basin is situated on the northeast coast of Brazil and it occupies the northern part of Rio Grande do Norte and Ceará states. It is a basin formed by the Cretaceous rift that occurred during the installation of the South Atlantic Ocean. The representatives of the Echinoidea class are abundantly present in the Jandaíra Formation, so that it s possible to find extensive banks composed of their shells. This study aimed to do the systematic review of the echinoid species from the Jandaíra Formation, Potiguar Basin. In this study we analyzed, described and illustrated 223 specimens of echinoids from six locations in Jandaíra Formation. The specimens were obtained from samples collected in 2003 and 2011, and deposited in the collection of the Phoenix Paleontological Foundation (FPH). Were identified and reviewed seven echinoids species: three regular echinoids, Rosadosoma riograndensis (Maury, 1925), Phymosoma major Coquand, 1862 and Goniopygus durandi (Perón & Gauthier, 1881), and four irregular ones: Petalobrissus setifensis (Cotteau, 1866), Petalobrissus cubensis (Weisbord, 1934), Mecaster fourneli (Deshayes in Agassiz & Desor, 1847) and Mecaster texanum (Roemer, 1852). The regular echinoids biometric data showed that the carapace diameter significantly influences the height of the carapace and the peristome diameter. The specimens of regular echinoids were in different ontogenetic stages, as well as the irregular ones, although the morphological characteristics were similar regardless of their stages. The specimens Petalobrissus setifensis and P. cubensis were compared among themselves and with the ones registered for other regions, as well as the M. fourneli and M. texanum specimens. Regarding to the paleobiogeographic quinoids distribution in Jandaíra Formation, it was observed that, on the locations here studied, the species of irregular echinoids exhibited a wider geographic distribution when compared to the regular species. The species of regular echinoids have a more frequent occurrence from the Turonian to the Santonian and the irregular species from the Turonian to the Campanian of the Jandaíra Formation. Our study was of great importance, since it contributed to the systematic review of the echinoids species and the in clarifying the possible junior synonyms and the morphological changes exhibited by the echinoids specimens in different ontogenetic stages. This study was of great importance, since it contributed in the systematic description and the morphological variations exhibited at the echinoids species in different ontogenetic stages. / O Cretáceo foi um período de muitas mudanças na superfície terrestre que contribuíram para o desenvolvimento de uma rica biodiversidade de organismos. A Bacia Potiguar está situada na costa Nordeste do Brasil, ocupando parte setentrional dos estados do Rio Grande do Norte e do Ceará. É uma bacia formada a partir do rift ocorrido no período Cretáceo durante a instalação do Oceano Atlântico Sul. Os representantes da classe Echinoidea estão presentes na Formação Jandaíra de forma abundante chegando a formar extensos bancos compostos por suas carapaças. Este estudo teve como principal objetivo fazer a revisão sistemática das espécies de equinoides da Formação Jandaíra, da Bacia Potiguar. Nesse trabalho foram analisados, descritos e ilustrados 223 exemplares de equinoides provenientes de seis localidades na Formação Jandaíra. Esses exemplares foram obtidos a partir de coletas realizadas em 2003 e 2011 e depositados no acervo da coleção da Fundação Paleontológica Phoenix (FPH). Foram identificadas e revisadas sete espécies de equinoides: três de equinoides regulares Rosadosoma riograndensis (Maury, 1925), Phymosoma major Coquand, 1862 e Goniopygus durandi (Perón & Gauthier, 1881); e quatro de irregulares Petalobrissus setifensis (Cotteau, 1866), Petalobrissus cubensis (Weisbord, 1934) Mecaster fourneli (Deshayes in Agassiz & Desor, 1847), e Mecaster texanum (Roemer, 1852). Os dados biométricos dos equinoides regulares mostraram que o diâmetro da carapaça influencia de forma significativa a altura da carapaça e o diâmetro do perístoma. Os exemplares de equinoides regulares apresentaram-se em diferentes estágios ontogenéticos, assim como os irregulares , porém as características morfológicas foram semelhantes independentes dos seus estágios. Os exemplares das espécies Petalobrissus setifensis e P. cubensis foram comparados entre si e com aqueles registrados para outras regiões, assim como os exemplares de M. fourneli e de M. texanum. Em relação à distribuição paleobiogeográfica dos equinoides na Formação Jandaíra foi observado nas localidades aqui estudadas que as espécies de equinoides irregulares apresentaram maior distribuição geográfica quando comparadas às espécies regulares . As espécies de equinoides regulares ocorrem mais frequentemente do Turoniano ao Santoniano e as irregulares do Turoniano ao Campaniano da Formação Jandaíra. Esse estudo foi de grande importância, pois contribuiu na descrição sistemática e variações morfológicas apresentadas nas diversas espécies de equinoides em diferentes estágios ontogenéticos.