Ciclo reprodutivo e distribuição espacial de Anomalocardia brasiliana (GMELIN, 1791) (Mollusca : Bibalvia : Veneriidae) na praia doCanto da Barra, Fortim, Ceará

• Ano de defesa: 2004
• Autor(a) principal: Araújo, Maria Lúcia Rodrigues
• Orientador(a): Rocha-Barreira, Cristina de Almeida
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: http://www.teses.ufc.br/
• Palavras-chave em Português: Moluscos; Anomalocardia brasiliana; Vângole; Marisco-pedra; Samambi; Fumim; Samanguaiá; Chumbinho; Muçunim; Mija-mija
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/1629

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, Ceará. 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: “in Ripening”, “Ripe”, “in Spawning”, “Spawned”. 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.