Reproductive aspects of the limpet Siphonaria lessoni (Gastropoda: Pulmonata) from the Southwestern Atlantic Ocean

KNACK DE ALMEIDA, HENRIQUE; JULIANA GIMÉNEZ

Pellston, Michigan

Congreso; 81st annual meeting of the American Malacological Society; 2015

American Malacological Society

Structuralcharacterization and reproductive cycle of Siphonarialessoni were investigated in Villa Gesell (37°16?S 56°58?O), at Buenos Aires Province. S. lessoni is a herbivore gastropod commonly found inhabiting hardsubstrates in the intertidal zone of rocky shores along the South-western Atlantic Ocean. Artificial structures such as fishing docksintroduced in sandy beaches like Villa Gesell, provides a new substratum forthis species settlement. Histological study of the gonad shows simultaneoushermaphroditism in this species. The stage of gonadal development and oocytessize frequency in the female portion as the presence of sperm in the maleportion were used to estimate reproductive events. The gametogenesis wasobserved asynchronous for both female and male portions between the gonad aciniThe oogenesis stages were defined by level of oocytes development. Previtellogenesisoocytes as early vitellogenic were found within a gonad throughout the year.The mature oocytes, ripe of vitello, were also found along the year but in higherfrequency during the beginning of the austral summer. Spermatogenesis wascontinuous along the year. The reproductive season in this species at thesampled site extended from November to February (austral summer). The reproductiveseasonality was associated with changes in water temperature and photoperiod.