De uma forma geral, animais ovíparos suprem sua prole somente com vitelo, composto principalmente por lipídios e proteínas. Em espécies de cecílias ovíparas e dermatófagas, as fêmeas mobilizam esses substratos energéticos para os ovários durante a vitelogênese e também utilizam esses mesmos compostos para a produção de uma pele mais espessa e nutritiva que servirá de alimento aos filhotes durante o cuidado parental. Em detrimento da grande importância do vitelo para o desenvolvimento de embriões e larvas, como apresentado, é curioso compreender como espécies ovíparas alocam parte da sua energia na produção de uma pele mais espessa, além de investirem na produção do vitelo. Desta forma, sendo as cecílias pouco conhecidas, é de grande importância entender os processos metabólicos e endócrinos envolvidos no armazenamento e na mobilização dos substratos energéticos ao longo do processo reprodutivo de machos e fêmeas, a fim de entender como ocorre o preparo das gônadas e da pele para a reprodução. Análises histológicas dos ovários e testículos foram realizadas, assim como a determinação de lipídios (e ácidos graxos dos fosfolipídios) e proteínas totais no fígado, músculo, gônadas, pele e plasma de machos e fêmeas de S. annulatus ao longo do ciclo anual. Além disso, a concentração plasmática dos esteróides gonadais (estradiol, testosterona e progesterona) foi também quantificada em ambos os sexos. De forma geral, oócitos em diferentes estágios de desenvolvimento foram encontrados nos ovários. A espermatogênese de Siphonops annulatus apresentou um padrão cístico como visto para os outros anamniotas, sendo o testículo formado por lobos que variam em número e tamanho. Com relação aos substratos energéticos, observamos que existe uma clara tendência em maior acúmulo de lipídios e proteínas nas gônadas das fêmeas que foram coletadas durante o inverno, caracterizadas por um desenvolvimento oocitário mais avançado, com a presença de oócitos vitelogênicos, sendo o mesmo observado para os machos. Em relação aos ácidos graxos, foi encontrado um padrão normalmente observado para os demais vertebrados, com a fração polar dos tecidos composta principalmente por ácidos graxos polinsaturados n6 em ambos os sexos. Destaca-se nas fêmeas uma grande mobilização de ácidos graxos dos tecidos de reserva para os ovários, principalmente os ácidos graxos polinsaturados, que são de grande importância para a vitelogênese e embriogênese. Alterações dos substratos no tecido dérmico da fêmea também foram observadas na primavera e no verão, sugerindo a importância deste tecido na dermatofagia. As análises hormonais demonstraram poucas variações ao longo do ano para ambos os sexos, devido à grande variação individual. Contudo, os valores de estradiol, testosterona e progesterona tendem a ser maiores para as fêmeas no inverno e para os machos durante a primavera. Os dados sugerem que o processo reprodutivo em S. annulatus mantida em cativeiro envolveu um processo de reostase programada, pois mesmo não havendo condições ambientais ideais, as fêmeas e os machos apresentam uma memória metabólica capaz de prepará-los para a reprodução. No entanto, o ambiente proporcionado pelo cativeiro suprimiu a ocorrência das fases finais do ciclo reprodutivo, como ovulação e cópula, resgatando o clássico conceito de reostase reativa. / Usually, oviparous animals keep their offspring only with yolk that is composed mostly of lipids and proteins. In oviparous and dermatophagic caecilians species, the females mobilize these energetic substrates to the ovaries during the vitellogenesis and also use these compounds to produce a ticker and nutritive skin that will be used as food for the offspring during parental care. In detriment of the great importance of the yolk to development of the embryos and larvae, as presented, it is curious to figure out how oviparous species allocate part of its energy to produce a thicker skin, beyond from investing in the production of yolk. Considering that caecilians are poorly known, it is important to understand the endocrine and metabolic processes involved in the storage and mobilization of energetic substrates during the reproductive process of males and females, in order to comprehend how the gonads and skin become ready for reproduction. Histological analysis of ovaries and testes were performed, as well as, total lipids (and fatty acids from phospholipids) and protein in liver, muscle, gonads, skin and plasma of males and females of S. annulatus during the annual cycle. Additionally, the plasma concentrations of gonadal steroids (estradiol, testosterone and progesterone) were quantified in both sexes. In general, oocytes at different stages of development were found in the ovaries. The spermatogenesis of Siphonops annulatus presented a cystic pattern as seen for other anamniotas, and the testes were formed by lobes which vary in number and size. Considering the energetic substrates, there is a clear tendency to a greater accumulation of lipids and protein in the ovaries in females collected in the winter, that were characterized by a more advanced stage of oocyte development, with the presence of vitellogenic oocytes. The same was observed for the males. Regarding to fatty acids, it was found a pattern commonly observed for others vertebrates, with the polar fraction of the tissues composed mainly by n6 polyunsaturated fatty acids in both sexes. It is important to highlight in females a great mobilization of fatty acids from the storages tissues to the ovaries, mainly the polyunsaturated fatty acids, which are of great importance for vitellogenesis and embryogenesis. Alterations in the energetic substrates of the dermal tissue of the female were also observed in spring and summer, suggesting the importance of this tissue in dermatophagy. The hormonal assays showed little variation throughout the year for both sexes, due to the large individual variation. However, the concentrations of estradiol, testosterone and progesterone have a clear tendency of being higher for females in the winter, and for males during the spring. The data suggests that the reproduction in S. annulatus maintained in captivity involved a programmed rheostasis process, because, even without the ideal environmental conditions, males and females presented a metabolic memory, that was enough to prepare the animals for reproduction. However, the environment provided by the captivity suppressed the occurrence of the final phases of the reproductive cycle, as ovulation and copulation, rescuing the classical concept of reactive rheostasis.

Esse trabalho teve como objetivo estudar aspectos importantes das estratégias reprodutivas de machos e fêmeas de Bothrops jararaca do clado norte (CN) e sul (CS) e das ilhas de Búzios (SP), Ilhabela (SP) e ilha dos Franceses (ES). Para isso, foram analisados exemplares de B. jararaca preservadas de diversas coleções zoológicas. Machos e fêmea de B. jararaca do CN foram significativamente maiores que os machos e fêmeas CS, no entanto tiveram cabeças relativamente menores e foram menos robustos. Fêmeas do CN têm em média maior fecundidade e filhotes maiores do que fêmeas do CS. O ciclo reprodutivo de machos e fêmeas de ambas as populações é sazonal e não variou entre as estações do ano. Fêmeas do CN e do CS tem cópula outonal. A vitelogênese tem início no final do verão e fêmeas grávidas são observadas a partir do final do inverno. Nascimentos de B. jararaca de ambos os clados podem ser observados principalmente no verão e podem se estender até o início do outono. A estocagem de espermatozoides no útero e no infundíbulo foi observada principalmente no outono e inverno. Ciclos reprodutivos de machos de ambos os clados são considerados do tipo pós-nupcial ou do tipo I. O início da produção de espermatozoides é na primavera e a fase ativa pode ser observada no verão. No outono e no inverno, os testículos estão inativos. Estocagem de espermatozoides nos ductos deferentes foi observada durante todos os meses do ano e o segmento sexual renal (SSR) apresentou a fase mais ativa (fase secretora) na primavera e verão (sincronizado com a espermatogênese nos testículos) e fase não secretora no outono e no inverno. Esse padrão dos ciclos dos machos foi observado em ambos os clados. Dessa forma, foram observadas variações geográficas nas características de histórias de vida entre as populações do CN e CS, porém, não foram observadas diferenças entre os padrões de ciclos reprodutivos. Assim, o ciclo reprodutivo de machos e fêmeas de B. jararaca do CN e do CS são conservativo na espécie. / This research aimed to study important aspects of reproductive strategies in male and female of Bothrops jararaca from north clade (CN), south clade (CS) including the islands of Búzios (SP), Ilhabela (SP), and Franceses (ES). We analyzed specimens of B. jararaca preserved on several zoological collections. Male and female of B. jararaca from CN were significantly longer than male and female from CS, however they had relatively smaller heads and were less robust. Male and female of B. jararaca from CN were significantly larger than individuals from CS, had relatively smaller heads and were less robust. Females from CN had on average higher fecundity and larger offspring than females of CS. The reproductive cycle of males and females from both populations was seasonal and the timing of events was also similar between clades. Females of CN and CS have autumn mating season. The vitellogenesis starts in the end of the summer and pregnant females are observed from late winter. Births of B. jararaca occurred from early summer to the beginning of autumn. Sperm storage in the uterus and infundibulum was mainly observed during autumn and winter. Reproductive cycles of male of both clades are type postnuptial or a type I. The beginning of the sperm production occurs in spring and the active phase was observed in the summer. During autumn and winter, the testicles are inactive. Sperm storage in the different ducts was observed throughout the year and the sexual segment of the kidney (SSK) shows a more active phase during spring and summer and non-secretory phase on autumn and winter. This pattern of cycles of male was observed in both clades. In conclusion, there is geographical variation in life-history characteristics between CN and CS populations. However, differences among the reproductive cycle pattern were not evident. Then, the reproductive cycles of male and female of CN and CS are conservative in the species.

Esse trabalho teve como objetivo estudar aspectos importantes das estratégias reprodutivas de machos e fêmeas de Bothrops jararaca do clado norte (CN) e sul (CS) e das ilhas de Búzios (SP), Ilhabela (SP) e ilha dos Franceses (ES). Para isso, foram analisados exemplares de B. jararaca preservadas de diversas coleções zoológicas. Machos e fêmea de B. jararaca do CN foram significativamente maiores que os machos e fêmeas CS, no entanto tiveram cabeças relativamente menores e foram menos robustos. Fêmeas do CN têm em média maior fecundidade e filhotes maiores do que fêmeas do CS. O ciclo reprodutivo de machos e fêmeas de ambas as populações é sazonal e não variou entre as estações do ano. Fêmeas do CN e do CS tem cópula outonal. A vitelogênese tem início no final do verão e fêmeas grávidas são observadas a partir do final do inverno. Nascimentos de B. jararaca de ambos os clados podem ser observados principalmente no verão e podem se estender até o início do outono. A estocagem de espermatozoides no útero e no infundíbulo foi observada principalmente no outono e inverno. Ciclos reprodutivos de machos de ambos os clados são considerados do tipo pós-nupcial ou do tipo I. O início da produção de espermatozoides é na primavera e a fase ativa pode ser observada no verão. No outono e no inverno, os testículos estão inativos. Estocagem de espermatozoides nos ductos deferentes foi observada durante todos os meses do ano e o segmento sexual renal (SSR) apresentou a fase mais ativa (fase secretora) na primavera e verão (sincronizado com a espermatogênese nos testículos) e fase não secretora no outono e no inverno. Esse padrão dos ciclos dos machos foi observado em ambos os clados. Dessa forma, foram observadas variações geográficas nas características de histórias de vida entre as populações do CN e CS, porém, não foram observadas diferenças entre os padrões de ciclos reprodutivos. Assim, o ciclo reprodutivo de machos e fêmeas de B. jararaca do CN e do CS são conservativo na espécie. / This research aimed to study important aspects of reproductive strategies in male and female of Bothrops jararaca from north clade (CN), south clade (CS) including the islands of Búzios (SP), Ilhabela (SP), and Franceses (ES). We analyzed specimens of B. jararaca preserved on several zoological collections. Male and female of B. jararaca from CN were significantly longer than male and female from CS, however they had relatively smaller heads and were less robust. Male and female of B. jararaca from CN were significantly larger than individuals from CS, had relatively smaller heads and were less robust. Females from CN had on average higher fecundity and larger offspring than females of CS. The reproductive cycle of males and females from both populations was seasonal and the timing of events was also similar between clades. Females of CN and CS have autumn mating season. The vitellogenesis starts in the end of the summer and pregnant females are observed from late winter. Births of B. jararaca occurred from early summer to the beginning of autumn. Sperm storage in the uterus and infundibulum was mainly observed during autumn and winter. Reproductive cycles of male of both clades are type postnuptial or a type I. The beginning of the sperm production occurs in spring and the active phase was observed in the summer. During autumn and winter, the testicles are inactive. Sperm storage in the different ducts was observed throughout the year and the sexual segment of the kidney (SSK) shows a more active phase during spring and summer and non-secretory phase on autumn and winter. This pattern of cycles of male was observed in both clades. In conclusion, there is geographical variation in life-history characteristics between CN and CS populations. However, differences among the reproductive cycle pattern were not evident. Then, the reproductive cycles of male and female of CN and CS are conservative in the species.

Orientador: Irani Quagio-Grassiotto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T21:34:55Z (GMT). No. of bitstreams: 1 Franca_GisleineFernanda_D.pdf: 12888107 bytes, checksum: b5adf2302500a4a5bb3ee0ced3071f53 (MD5) Previous issue date: 2010 / Resumo: Gymnotiformes, os peixes faca, constituem um importante componente da fauna Neotropical de água doce das Américas Central e do Sul. Este grupo compreende mais de 100 espécies válidas, distribuídas em 27 gêneros. Gymnotus sp., representante da família Gymnotidae, é conhecido regionalmente como tuvira, morenita, ituí ou sarapó. Apesar do fato que a dinâmica reprodutiva, morfologia do aparelho reprodutor e a histologia das gonâdas de Gymnotus sp. terem sido abordadas por alguns autores, informações detalhadas das alterações histológicas e fisiológicas durante o ciclo reprodutivo não estão disponíveis. Considerando a importância deste grupo de peixes na região Neotropical, o ciclo reprodutivo de Gymnotus sp. foi reavaliado. Obteve-se, além disto, as concentrações plasmáticas dos esteróides, dados da histologia gonadal, imunocitoquímicos, de atividade enzimatica e proliferação celular. As gônadas de Gymnotus sp. localizam-se ventralmente na cavidade celomática e são conectadas por longos ductos à papila urogenital e que tem posição anterior no corpo do animal. Ovários são fundidos, e a morfologia interna de ambos, ovário e testículo, não diferem de outros Ostariophysi . O ciclo reprodutivo em fêmeas e machos foi dividido em cinco fases, de acordo com uma nova abordagem do desenvolvimento das células germinativas. Esta classificação, desenvolvida para ser universal, para ovário assim como para o testículo, melhor expressa as alterações histológicas durante o ciclo reprodutivo em Gymnotus sp.. A relação entre o índice gonadossomático e características histológicas nas fases reprodutivas foi realizada. As concentrações plasmáticas de estradiol e 11-cetotestosterona foram pouco variáveis em fêmeas, possuindo, ambos, tendência a maiores valores no início do ciclo reprodutivo e em animais com ovários possuindo oócitos aptos a desova. As concentrações de testosterona se elevam conforme o ovário desenvolve-se, sugerindo uma possível relação do hormônio com o desenvolvimento dos folículos. As células da teça responderam positivamente à localização da enzima 3? hidroxiesteróide desidrogenase que está de acordo com as concentrações plasmáticas da testosterona. Inesperado e nunca reportado para os Teleostei, as células foliculares também reagem a detecção da 3? hidroxiesteróide desidrogenase. Em machos as concentrações plasmáticas de estradiol permanecem, praticamente, constantes durante todo o ciclo reprodutivo. A concentração plasmática de 11- cetotestosterona possui tendência a concentrações elevadas no início do ciclo, com uma queda gradual até a fase de maturação final, quando há nova elevação. O perfil hormonal da testosterona é semelhante aos dados de proliferação de espermatogônias secundárias, sugerindo uma possível relação entre as concentrações hormonais e os eventos proliferativos. Juntos concentração plasmática de esteróides, histologia gonadal, imunocitoquímica, atividade enzimática e detecção de proliferação celular forneceram uma nova compreensão do ciclo reprodutivo em Gymnotus. / Abstract: Gymnotiformes, the American knifefish, constitute an important component of the Neotropical freshwater fauna in the Central and South America. This group comprises more than 100 valid species, divided in 27 genera. Gymnotus sp., a representative of the family Gymnotidae, regionally known as tuvira, morenita, ituí or sarapó, is the best known gymnotid. Despite the fact that reproductive dynamic, morphology of the reproductive systems and the gonadal histology of Gymnotus sp. have been studied by some authors, detailed information on histological and physiological changes of the gonads along the reproductive cycle are not available. Considering the importance of this group of fish in the Neotropical region, the reproductive cycle of Gymnotus sp. has been reevaluated. Besides plasma steroids concentration along the reproductive cycle, data from gonadal histology, imunocitochemistry, enzymatic activity and cell proliferation were obtained. Gonads of Gymnotus sp. are ventrally located in the coelomic cavity and connected by long ducts to the urogenital papilla which has an anterior position in the animal body. Ovaries are fused, and the internal morphology of both, ovary and testis, do not differ from other ostariophysians. The reproductive cycle in females and males was divided in five phases, according to a new approach from the germ cells development. This classification, developed to be universal, for ovary as well as for testis better express the histological alterations during reproductive cycle in Gymnotus sp. The relation between the gonadossomatic index and the histological characteristics of the reproductive phases was done. Plasma concentrations of estradiol and 11-ketotestosterone were low variable in females, having, both, a tendency to high values in the beginning of the reproductive cycle and in animal's ovary with oocytes able to spawn. Testosterone concentration increasingly elevate as ovary develops, suggesting a possible relation with the follicles growth. The cal cells positivity for the enzymatic detection of 3? hidroxisteroid desidrogenase is in agreement with the plasma concentration of testosterone. Unexpected and never reported in Teleostei also the follicle cells react to the enzimatic detection of the 3? hidroxisteroid desidrogenase. In males, the plasma concentrations of estradiol remain approximatly constant along the reproductive cycle. Plasma concentration of 11-ketotestosterone tends to be high at the beginning of the cycle, with a gradual decrease at the final maturation phase, in which there is a new elevation. The highest concentration of testosterone along the male reproductive cycle coincids with the secondary spermatogonia proliferation, suggesting a possible relation between the concentration of this hormone and the proliferative events. Together plasma steroids concentration, gonadal histology, imunocitochemistry, enzymatic activity and detection of cell proliferation provide a new compreension of the reproductive cycle in Gymnotus. / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

Os bivalves marinhos sÃo muitos apreciados como alimento e no aproveitamento de suas conchas para vÃrias utilidades especialmente como enfeites. A presente pesquisa teve como objetivo estudar o bivalve marinho venerÃdeo Anomalocardia brasiliana, quanto a densidade populacional e ciclo de reproduÃÃo, correlacionando este Ãltimo aos parÃmetros ambientais (salinidade, temperatura e precipitaÃÃo pluviomÃtrica). As amostragens foram realizadas mensalmente durante o perÃodo de maio/02 a abril/03, na praia do Canto da Barra, municÃpio de Fortim â CE, no estuÃrio do Rio Jaguaribe. Os indivÃduos Anomalocardia brasiliana apresentaram um padrÃo de distribuiÃÃo bem caracterÃstico, com os juvenis concentrados em Ãrea com sedimento fino e mais Ãmido e os adultos em banco arenosos com sedimento mais grosseiro. A diferenciaÃÃo sexual ocorreu provavelmente entre 12,6mm e 17,9mm de comprimento de conchas. A identificaÃÃo dos sexos foi realizada utilizando-se tÃcnicas histolÃgicas de rotina. Durante a gametogÃnese, foram reconhecidas em fÃmeas, ovogÃnias, ovÃcitos prÃ-vitelogÃnicos, ovÃcitos vitelogÃnicos e ovÃcitos maduros, e, em machos, espermatogÃnias, espermatÃcitos I, espematÃcitos II, espermÃtides e espermatozÃides. A reproduÃÃo da espÃcie à contÃnua, entretanto foram observados perÃodos de maior liberaÃÃo de gametas de julho a outubro/2002 e de fevereiro a abril/2003. O ciclo reprodutivo caracterizou-se pelas seguintes as fases do desenvolvimento gonadal: âem MaturaÃÃoâ, âMaduroâ, âem EliminaÃÃoâ, âEliminadoâ, para ambos os sexos. Dentre os fatores ambientais observados neste estudo, a precipitaÃÃo pluviomÃtrica e a salinidade foram as que apresentaram as maiores amplitudes de variaÃÃo. Entretanto, uma influÃncia significativa do efeito da diminuiÃÃo da salinidade foi observada somente em machos, provavelmente causada pela alta precipitaÃÃo pluviomÃtrica verificada em abril/03. Durante este estudo, observou-se a ocorrÃncia de parasitas do gÃnero Bucephalus sp. em 6,5% dos indivÃduos analisados. Apesar da baixa incidÃncia de organismos parasitados, a ocorrÃncia de parasitismo na populaÃÃo de Anomalocardia brasiliana, no estuÃrio do Rio Jaguaribe, alerta para necessidade de estudo sobre as condiÃÃes fisiolÃgicas desta espÃcie na regiÃo. / Marine bivalves are very appreciated as food and its shell is used for several purposes, especially for ornament. The present research aims to study the marine bivalve Anomalocardia brasiliana in relation to its population density and reproductive cycle, correlating them with environmental parameters (salinity, temperature and precipitation). Monthly samplings were realized from May 2002 to April 2003 at Canto da Barra Beach, in the Jaguaribe River Estuary, Fortim, CearÃ. The Anomalocardia brasiliana individuals presented a quite characteristic distribution pattern, with the juvenile ones concentrated in areas with fine and moist sediment (fine sand) and the adult ones concentrated in sandy beds with coarse sediment (medium sand). Sexual differentiation probably occurred when the shell length was between 12,6mm and 17,9mm. Sex determination was realized using custom histological techniques. During gametogenesis, oogonia, previtellogenic oocytes, vitellogenic oocytes and mature oocytes were recognized in females, and spermatogonia, spermatocytes I, spermatocytes II, spermatids and spermatozoa were recognized in males. The reproductive cycle is continuous. Nevertheless, periods of intense gamete liberation were observed from July to October 2002 and form February to April 2003. For both sexes the reproduction cycle was characterized by the following stages in the development: âin Ripeningâ, âRipeâ, âin Spawningâ, âSpawnedâ. Among the environmental agents observed in this study, precipitation and salinity were the ones that presented the largest fluctuation in amplitude. However, a major influence by the salinity reduction effect was only observed in males, probably caused by the high precipitation registered in April 2003. During this study, the occurrence of parasites from the genus Bucephalus sp. was observed in 6,5% of the analyzed individuals. Despite the low influence of organisms infected with parasites, the occurrence of parasitism in the Anomalocardia brasiliana population at the Jaguaribe River Estuary alerts the necessity for further studies on the physiological conditions of this species in that area.

A tabarana Salminus hilarii (Characiformes) é uma espécie reofílica de grande importância ecológica na Bacia do Alto Tietê (São Paulo/SP, Brasil). Atualmente esta espécie sofre com a poluição (industrial e doméstica) e a construção de barragens na região, o que pode prejudicar o comportamento migratório reprodutivo das espécies reofílicas, bloqueando a reprodução. O presente estudo tem como objetivo analisar os mecanismos fisiológicos envolvidos no controle endógeno da reprodução Salminus hilarii, analisando-se o eixo hipófise-gônadas. Adicionalmente, buscou-se avaliar se o bloqueio da migração reprodutiva (parcial ou total) altera o funcionamento deste eixo. Os animais foram coletados no ambiente natural (Bacia do Alto Tietê), na saída da Barragem da Barragem de Ponte Nova e na Piscicultura de Ponte Nova (Salesópolis/SP) durante o período de abril de 2004 e agosto de 2006. As análises macro e microscópicas das gônadas e os valores de IGS mostraram que o período reprodutivo da tabarana ocorreu entre os meses de outubro a fevereiro. As análises macroscópicas e microscópicas dos ovários e dos testículos permitiram classificar o desenvolvimento ovariano em 4 estádios: repouso, maturação inicial, maturação avançada (cativeiro), maduro (ambiente natural) e regressão/esgotado e o desenvolvimento testicular em 3 estádio: repouso, maduro e regressão. O desenvolvimento oocitário da tabarana é do tipo sincrônico em grupo e a desova é total; os testículos são do tipo tubular anastomosado e espermatogonial irrestrito. Foram identificados 5 tipos celulares no interior dos ovários: oogônias, oócito perinucleolar, oócito cortical-alveolar, oócito vitelogênico e oócito maduro, além de estruturas derivadas desse desenvolvimento, os folículos pós-ovulatórios e os oócitos atrésicos. Identificou-se também 6 tipos celulares no interior dos testículos: espermatogônias, espermatócitos, espermátides, espermatozóides, células de Sertoli e células de Leydig. A hipófise de S. hilarii é composta de dois tecidos: a adeno-hipófise (tecido glandular endócrino) e a neuro-hipófise (origem nervosa). Adicionalmente, foi verificado que a adeno-hipófise é subdividida em: “rostral pars distalis” (RPD), “proximal pars distalis” (PPD) e “pars intermedia” (PI). Seis tipos celulares foram identificados na adeno-hipófise: as células produtoras de prolactina (PRL) e as células produtoras de hormônio adrenocorticotrópico (ACTH) foram identificadas na região da RPD; as células produtoras de hormônio de crescimento (GH) e as células produtoras de gonadotropinas (GtHs) estão situadas na região da PPD; as células produtoras de melanotropina (MSH) e as células produtoras de somatolactina (SL) estão presentes na PI. As células PRL não apresentam variações ao longo do ciclo reprodutivo da tabarana, no entanto, as células produtoras de GH diminuem a porcentagem de imunomarcação com o avanço do ciclo reprodutivo. Já as células produtoras de SL aumentam a porcentagem de imunomarcação com o desenvolvimento das gônadas. Adicionalmente, foi verificada a presença de duas gonadotropinas na região da adeno-hipófise, o hormônio folículo estimulante (FSH) e o hormônio luteinizante (LH). Em relação ao perfil plasmático dos esteróides gonadais, foi verificado que o estradiol aumenta com o avanço do ciclo reprodutivo, diminuindo do estádio maduro para o estádio regressão/esgotado (ambiente natural). No cativeiro ocorreu um aumento da concentração de estradiol do estádio repouso até o estádio maturação média, diminuindo logo em seguida nos estádios maturação avançada e regressão/esgotado. A concentração de testosterona eleva-se com o avanço da maturação gonadal, atingindo os valores máximos no estádio maduro (ambiente natural) e maturação avançada (cativeiro). Paralelamente, o estradiol apresentou-se alto somente na maturação média (cativeiro) e maduro (ambiente natural), evidenciando uma relação entre esses dois hormônios. Valores mais elevados de 17α-hidroxiprogesterona no cativeiro sugerem uma deficiência na conversão deste esteróide para17α, 20β-dihidroxy-4-pregnen-3-one, considerado como o hormônio indutor da maturação final e ovulação na maioria dos teleósteos. Os resultados encontrados evidenciam que o bloqueio da migração altera a fisiologia do eixo hipófise-gônadas em Salminus hilarii. / The tabarana Salminus hilarii (Characiformes) is a reofilic species of great ecological importance in the Region of the Alto Tietê Basin (São Paulo/SP, Brazil). This fish reaches greater sizes in this Basin and as a carnivorous species, which occupies the top of the alimentary chain. Nowadays, the Tietê Basin is affected by pollution (industrial and domestic) and dam constructions in the upper reaches of the river, hindering the reproductive migratory behavior of the reofilic species. When the “piracema” fish migration is obstructed, the reproduction fails, making evident, that the dam construction in the Brazilian rivers causes great impacts in the life cycle of the reofilic teleost. The aim of this study was analyze the physiological mechanisms involved in Salminus hilarii reproduction, analyzing the pituitary-gonads axis and additionally, to evaluate if the migration impediment (partial or total) modifies this axis physiology, and consequently the endogenous control of tabarana reproduction. From April 2004 to August.2006, the animals were collected in the natural environment (upper Tietê Basin), in the water exit of Ponte Nova Dam (Department of Water and Electric Energy) and in the Ponte Nova Dam Fishfarm (Salesópolis/SP). The microscopical analyses of the gonads and analyses of the gonadossomatic Index showed that the reproductive period of the tabarana occurred between October and February. The macroscopic and microscopical analyses of the ovaries and testis allowed to classify the ovarial development in 4 stages: resting, initial maturation, advanced maturation (captivity) or maturity (natural environmental) and regression/spawned, and the testis development in 3 stages: resting, mature and regression. The tabarana oocyte development is group-synchronous and the spawning is total. The anastomosing tubular testis and unrestricted spermatogonia were observed. Five cellular types in the interior of the ovaries were identified: oogonia, perinucleolar oocyte, cortical alveolar oocyte, vitellogenic oocyte and ripe oocyte, and beyond structures derived from this evelopment, the post-ovulatory follicles and the atretic oocyte. In the testis, 6 cellular types were identified: spermatogonia, spermatocytes, spermatids, spermatozoa, Sertoli cell and Leydig cell. S. hilarii pituitary is composed of two different tissues: adenohypophysis (endocrine tissue) and neurohypophysis (nervous origin). Additionally, it was verified that adenohypophysis is subdivided in: “rostral pars distalis” (RPD), “proximal pars distalis” (PPD) and “pars intermedia” (PI). Six cellular types were identified in adenohypophysis: prolactin cells (PRL) and adenocorticotropin cells (ACTH) have been identified in the RPD region; growth hormone cells (GH) and the gonadotropinas cells (GtHs) were situated in the PPD region; melanotropin cells (MSH) and somatolactin cells (SL) were present in the PI. PRL cells did not present variations throughout the reproductive cycle of the tabarana. However, the GH reaction showed a decrease in the cells stained percentage with the advance of the reproductive cycle. Also the SL cells increased the stained percentage along the gonads development. Additionally, the presence of two gonadotropins in the region of adenohypophysis, the follicle-stimulating hormone (FSH) and the luteinizing hormone (LH) was identified. The plasma levels of sex steroids showed that estradiol increased with the advance of the reproductive cycle, diminishing from the mature to the regression/spawning stage (natural environmental). In captivity an increase of the estradiol concentration from the resting to the medium maturation stage was observed, diminishing immediately afterwards in advanced maturation and regression/spawning stage. The testosterone concentration increased with the advance of the gonadal maturation, reaching the maximum values in the mature stage (natural environmental) and advanced maturation stage (captivity). On the other hand, estradiol was high only in the medium maturation (captivity) and ripe stage (natural environmental), evidencing an interdependence between these two steroids. The progestagene analyses showed that, in all maturation stages, 17α OHP levels were higher in captivity than in the natural environment, suggesting that the conversion of this steroid to 17α20β DHP (MIS) is affected in impaired environments, and that the conversion enzyme (20β desidrogenase) fails when migration is blocked. The results allow to conclude that the migration impairment change negatively the pituitary-gonads axis in S. hilarii.

Un des moyens de développer durablement l’aquaculture européenne est la domestication d’espèces locales. Etant donné les coûts liés à la domestication d’une espèce, la mise en œuvre d’une démarche générique semble pertinente. Ainsi, l’analyse de 29 traits reproducteurs a généré une classification en 10 groupes structurés par la période de ponte et la température d’incubation des œufs. L’objet de cette thèse est de tester la pertinence de ces regroupements en étudiant l’effet d’une photophase constante longue PC et naturelle PN sur l’induction du cycle de reproduction chez des pondeurs printaniers précoces PPP (perche, sandre, gardon et brochet) et un pondeur printanier tardif PPT (rotengle). Au cours de ce travail, nous avons analysé des paramètres morpho-anatomiques, histologiques et physiologiques pour étudier les effets des traitements photopériodiques. De fortes similarités de réponse au traitement photopériodique entre les PPP ont été observées avec une inhibition du cycle de reproduction sous PC et une induction du cycle de reproduction sous PN. Si le développement gonadique et les teneurs en E2 et vitellogénine chez les femelles semblent être affectés de la même manière chez les espèces du même groupe, les teneurs en androgènes chez les deux sexes présentent des réponses espèce-spécifiques. Ceci suggère l’existence de mécanismes de régulation spécifiques qui semblent avoir peu de conséquences zootechniques. En conclusion, les similarités entre les PPP apportent des éléments de réponse sur la pertinence des regroupements surtout au niveau des paramètres les plus intégrateurs et sur la pertinence de la démarche générique qui s’appuie sur la biologie comparée / A way for the development of a sustainable inland aquaculture is the domestication of local species. As domestication usually results from a long, costly and empirical zootechnical process, the use of classifications could be a relevant strategy. In our laboratory, a generic method was developed based on grouping species sharing similar reproductive traits (29) and resulted in 10 clusters structured by spawning period and temperature of egg incubation. The aim of this work is to assess the relevance of this clustering by testing the effect of constant long (CP) and natural photoperiod (NP) on the onset of the reproductive cycle in “early spring” ESS (Eurasian perch, pikeperch, roach and pike) and a “late spring” spawner LSS (rudd). This work is based on a morpho-anatomic, histological and physiological analysis of the broodstock to study the effect of photoperiod treatments. Strong similarities were shown in the response of the ESS with inhibition of the reproductive cycle under CP and induction under NP. The gonadal development and the plasma levels of E2 and vitellogenin showed similar responses to the photoperiodic treatment between ESS, while, the androgens levels showed different responses even in species belonging to the same group and the same family. The observed similarities allow us to provide an evidence about the relevance of clusters especially for the most integrative parameters. However, even if extrapolation of current knowledge may be possible from Eurasian perch to other ESS especially for zootechnical purposes, the mechanisms of gonadogenesis regulation and especially androgenesis may be different between the studied species

Le métabolisme secondaire joue un rôle écologique majeur dans les interactions des organismes avec leur environnement. Une étude intégrée de la biologie, de l’écologie des organismes et des variations de leur métabolisme est essentielle pour comprendre le rôle des métabolites secondaires au sein des écosystèmes. Or ce type d’approche est rare en milieu marin.Le petit clade d’éponges Homoscleromorpha constitue un vrai potentiel de découverte de nouvelles espèces et de molécules bioactives valorisables. Par ailleurs, leur position de dominance dans certaines communautés benthiques de Méditerranée en faisait un modèle de choix pour démarrer des recherches en écologie chimique marine.Ce travail a débuté avec la description d’une espèce du genre Oscarella, O. balibaloi ainsi que de nouvelles molécules produites par cet organisme. Cette nouvelle espèce avec deux autres espèces communes du même genre, O. tuberculata et O. lobularis constituent parfois de vrais faciès au sein des communautés du coralligène et des grottes semi-obscures. L’étude comparée du cycle de vie de ces Oscarella a montré dans tous les cas une reproduction saisonnière, avec des différences dans les périodes de gamétogénèse et d’émission des larves, et des sensibilités variables face aux changements des conditions de régime thermique. Deux composés majoritaires de type lysophospholipides ont été isolés et caractérisés pour la première fois dans O. tuberculata, et retrouvés dans O. lobularis. Leur rôle potentiel de médiateurs moléculaires impliqués dans le processus de reproduction (embryogenèse et développement) a été proposé, et devra être confirmé par des études expérimentales. Une nouvelle famille de sesterterpènes glycosylés (dénommés balibalosides) a été découverte dans O. balibaloi.Une étude pluriannuelle des variations du métabolisme de ces espèces a été réalisée à travers trois approches complémentaires permettant de tester les modalités d’allocation des ressources à la production de métabolites secondaires. Les patrons de variation des niveaux d’expression de métabolites ciblés, des signatures métaboliques et des bioactivités des extraits d’éponges ont montré une influence significative du cycle de reproduction sur le métabolisme secondaire. Les méthodes globales (métabolomique et bioactivité) ont permis de montrer que le cycle de variation du métabolisme secondaire était marqué par une modification importante de sa production accompagnée par une baisse de bioactivité pendant les périodes les plus coûteuses de la reproduction (reproduction asexuée, embryogenèse et développement larvaire). Ces résultats montrent un compromis d’allocation des ressources entre un métabolisme primaire (la reproduction) et la production des métabolites secondaires, et soutient ainsi la théorie de défense optimale.L’approche de métabolomique s’est avérée un bon indicateur de la chimio-diversité. Appliquée à l’étude des relations inter-spécifiques, cette méthode de chimio-systématique a permis de proposer une classification des espèces méditerranéennes d’Homoscleromorpha. Cette classification soutient les résultats les plus récents de phylogénie moléculaire et propose la restauration de deux anciens clades au sein des Homoscleromorpha: les Plakinidae, un groupe qui ne contient aujourd’hui que des espèces à squelette, et les Oscarellidae qui ne contient que des espèces sans squelette. Les approches développées au cours de cette thèse permettent de nombreuses perspectives en chimio-systématique et écologie chimique marine. L’utilisation des signatures métaboliques peut être transposée à d’autres questions de systématique, particulièrement pour démontrer l’existence d’espèces cryptiques, et pour soutenir des hypothèses phylogénétiques au sein d’autres clades problématiques [...] / Secondary metabolism plays a major ecological role in the interactions between the organisms and their environment. An integral study of the organisms’ biology and ecology and the variations of their metabolism is essential for understanding the role of secondary metabolites in the ecosystems. This kind of approach is rare in the marine environment. Small sponge clade Homoscleromorpha constitutes a real potential for the discovery of new species and potentially bioactive molecules. In addition, its dominance in some Mediterranean benthic communities makes it a good model in marine chemical ecology research. This work has started with a description of new species of Oscarella genus, O. balibaloi. This new species forms sometimes, with two other commun Oscarella species, O. tuberculata and O. lobularis, special facies within the coralligenous and semi-dark cave communities. All three Oscarella species are caraterized by a seasonal reproductive cycle with differences in the period of gametogenesis and larval emission as well as the variation in sensitivity facing the changes in thermal regime. Two major lysophospholipid compounds were isolated and caracterized for the first time in O. tuberculata and confirmed in O. lobularis. Their potential role as signal molecules in the reproduction process (embryogenesis and development) was proposed and should be confirmed by experimental studies. One new familly of glycosilated seterterpens (named balibalosides) was found in O. balibaloi. A pluriannual study of species metabolism was performed using three complementary approaches and enabled to test the models of resource allocation to secondary metabolite production. Variation patterns in the expression level of target metabolites, in the metabolic fingerprints and the bioactivities of sponge extracts reflected the significant influence of the reproductive cycle to the secondary metabolite production. Holisitic approaches (métabolomics and bioactivity) pointed out the important modification in the secondary metabolism variation pattern followed by the decrease in bioactivity during the costly period of reproduction (asexual reproduction, embryogenesis and larval development). These results highlight the trade-off in resource allocation between the primary (reproduction) and secondary metabolism and therefore support the Optimal Defense Theory. Metabolomic approach applied to the study of interspecific relations turned out as a good indicator of chemical diversity which allowed the classification of Mediterranean Homoscleromorpha sepcies. The obtained classification was congruent with recent molecular phylogeny results proposing the restauration of two ancient clades within Homoscleromorpha, the Plakinidae, a group of species possesing skeleton and the Oscarellidae, a group of species lacking skeleton. Approaches developed during my thesis opened a numerous perspectives in chemosystematics and marine chemical ecology. The use of metabolic fingerprints can be transposed to other questions in systematics, particularly to demonstrate the existance of cryptic species and to support phylogenetic hypothesis within other problematic clades. [...]

Made available in DSpace on 2014-12-17T15:36:35Z (GMT). No. of bitstreams: 1 LeonardoBR_TESE_Cap_II_III.pdf: 677404 bytes, checksum: 247b1251f8d1d16cb41bf4f8ec2f3c18 (MD5) Previous issue date: 2010-03-19 / Universidade Federal do Rio Grande do Norte / This study evaluated the spatial, time and alimentary niches of Tropidurus hispidus and Tropidurus semitaeniatus in sympatry in a caatinga of Rio Grande do Norte, Brazil, as well as their foraging and termoregulatory behaviors, the activity body temperature and their reproductive and fat body cycles. Monthly excursions, from October 2006 to May 2008, were conducted at the Ecological Station of the Serid? (ESEC Serid?), Serra Negra do Norte municipality, using specific methodology for investigation of the aforementioned objectives. The two species presented similarities in space niche use, mainly in rocky habitat, however they differed in vertical microhabitat use with T. hispidus using a larger vertical microhabitat range. In the dry season the time of activity of both species was bimodal. In the wet season T. semitaeniatus showed a unimodal activity period, while T. hispidus maintained an bimodal activity period. In terms of importance in the diet, to both species, Hymenoptera/Formicidae and Isoptera predominated during the dry season. In the wet season, although Hymenoptera/Formicidae had larger importance among the prey items, lizards opportunistically predated on Lepidoptera larvae, Coleoptera larvae/adults and Orthoptera nymphs/adults. The foraging intensity revealed differences between the species, mainly in the wet season, when T. semitaeniatus was more active than T. hispidus. The mean activity body temperature of T. semitaeniatus was significantly higher than that of T. hispidus. The thermoregulatory behavior showed that during the dry season T. hispidus and T. semitaeniatus spent more time in shade or under filtered sun. In the wet season, T. hispidus did not show differences in the amount of time spent among the light exposure locations, however T. semitaeniatus spent most of their time exposed to direct sun or filtered sun. The reproductive cicle of T. hispidus and T. semitaeniatus occurred from the middle of the dry season to the beginning of the wet season. In both species, female reproductive activity was influenced by precipitation, whereas males exhibited spermatozoa in their testes throughout the year, and their reproductive activity was not related with any of the climatic variables analysed. In the two species, the fat storage varied inversely with reproductive activity, and there was no difference in fat body mass between females and males. We concluded that the segregation between T. hispidus and T. semitaeniatus in this caatinga area occurs in vertical space use, in the largest vagility of T. hispidus in microhabitat use and larger range size of their alimentary xviii items. Additionally, significant seasonal differences in relation to the activity period, body temperature, and foraging and termoregulatory behaviors between these two Tropidurus species facilitate their coexistence. / Este estudo avaliou o uso dos recursos espacial, temporal e alimentar por Tropidurus hispidus e Tropidurus semitaeniatus em simpatria em uma caatinga do Rio Grande do Norte, Brasil, bem como seus comportamentos de forrageamento e termorregulat?rio, suas temperaturas corp?reas em atividade e seus ciclos reprodutivos e de gordura corp?rea. Excurs?es mensais, de outubro de 2006 a maio de 2008, foram realizadas ? Esta??o Ecol?gica do Serid? (ESEC Serid?), munic?pio de Serra Negra do Norte, com utiliza??o de metodologia espec?fica para a investiga??o dos objetivos acima mencionados. As duas esp?cies apresentaram similaridades no uso do nicho espacial, especialmente no h?bitat rochoso; contudo, elas diferiram no uso vertical do micro-h?bitat com T. hispidus usando uma faixa vertical maior do micro-h?bitat. Na esta??o seca o per?odo de atividade de ambas as esp?cies foi bimodal. Na esta??o chuvosa, a atividade de T. semitaeniatus mostrou um per?odo unimodal, enquanto T. hispidus manteve uma atividade bimodal. Em termos de import?ncia na dieta, para ambas as esp?cies, os Hymenoptera/Formicidae e Isoptera predominaram na esta??o seca. Na esta??o chuvosa ainda que os Hymenoptera/Formicidae continuaram a ter maior import?ncia entre os itens alimentares, os lagartos predaram oportunisticamente larvas de Lepidoptera, larvas/adultos de Coleoptera e ninfas/adultos de Orthoptera. A medida de intensidade de forrageamento revelou diferen?as entre as esp?cies, especialmente na esta??o chuvosa, quando T. semitaeniatus foi mais ativo do que T. hispidus. A temperatura corp?rea m?dia em atividade de T. semitaeniatus foi significativamente superior a de T. hispidus. O comportamento termorregulat?rio mostrou que, durante a esta??o seca, T. hispidus e T. semitaeniatus gastaram mais tempo expostos ? sombra ou sob sol filtrado. Na esta??o chuvosa, T. hispidus n?o mostrou diferen?as no tempo gasto entre os locais de exposi??o ? luz, contudo T. semitaeniatus esteve a maior parte de seu tempo exposto ao sol ou sob sol filtrado. A reprodu??o de T. hispidus e T. semitaeniatus ocorreu entre a metade da esta??o seca e o in?cio da esta??o chuvosa. Em ambas as esp?cies, a atividade reprodutiva das f?meas foi influenciada pela precipita??o, enquanto os machos apresentaram espermatoz?ides nos test?culos ao longo de todo o ano, e sua atividade reprodutiva n?o foi relacionada com nenhuma das vari?veis clim?ticas analisadas. O estoque de gordura corp?rea variou inversamente com a atividade reprodutiva nas duas esp?cies, e n?o houve diferen?a entre f?meas e machos quanto a massa dos corpos adiposos. Conclu?mos que xvi a segrega??o entre T. hispidus e T. semitaeniatus nesta ?rea de caatinga ocorre no uso vertical do espa?o, na maior vagilidade de T. hispidus na utiliza??o de micro-h?bitats e maior amplitude de tamanho de seus itens alimentares. Adicionalmente, diferen?as sazonais significativas em rela??o ao per?odo de atividade, temperatura corp?rea, e comportamentos de forrageamento e termorregulat?rio entre essas duas esp?cies de Tropidurus, possibilitam a coexist?ncia.

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.