Reproductive periods of Lucina pectinata (BIVALVE; LUCINIDAE) in the Paranagu?? Estuarine Complex, Paran?? - Brazil

摘要

The objectives of the present study is to describe the size for exploitation and gonadal maturation of L. pectinata in Pe?§as Island in Paran?? coast. Twenty two individuals were sampled every month, from an intertidal flat of the Pe?§as River, Municipality of Guaraque?§aba, during two periods a?? summer/autumn and winter of the 2009. Environmental parameter data was obtained at the same time of the biological sampling: temperature, salinity and seawater transparency at the Pe?§as River mouth. The animalsa?? height, length, width, gross weight, wet weight of meat and dry weight of meat were measured at the lab. The gonad development stages (GDS), condition index (CI) and yield index (Y) were calculated. Sex identification was conducted by direct observation of the gonads and gametes under an optic microscope. Individuals were classified as males (M), females (F) or undetermined (U). The medium height observed was of 49.62 ?± 6.84 mm. Period of more expressive gonad repletion were observed in summer when water temperature was higher. Results of GDS in both periods showed a predominance of partially filled gonad stages. This may be related with the fact that L. pectinata has intense gametogenesis activity, that is, the organisms do not have a resting interval, but go back to gonad restructuring rapidly after releasing the gametes. The continuity of the reproductive cycle of the specimens found in both studied periods could demonstrate a possible continuous reproduction of the species and a size for exploitation above 40.00 mm of height.