The reproductive cycle of Potomida littoralis (Cuvier,1798) (Bivalvia: Unionidae) in Lake Gölbaşi,Turkey

In this work,reproductive cycle of potomida littoralis,including histological description and indices of gonad maruration were investigated. there is no data previously available on the species. a total of 300 individuals were monthly collected from september 2009 to august 2010 in gölbaşi lake,turkey. p. littoralis is dioecious and although males tended to predominate,the sex ratio was not significantly different from the expected 1:1 ratio (p>0.05). calculation of the condition index (ci),gonadosomatic index (gsi) and histological examination of the gonads showed that gametogenesis began in january. spawning occurred in june. annual maximum gsi value peaked in may. a decrease of ci was observed during gametogenesis. when mussels had the highest gsi value,ci was the lowest value. this results suggest that gametogenesis and reproductive cycle are the key factor in mussels physiology and important for captive breeding/artificial mussels production and conservation status (e.g. when to obtain gravid females,when to relocate,when to restock,when to introduce fish host,when not to allow harvesting). copyright 2013 zoological society of pakistan.