Reproductive cycle of the south American scallop Amusium laurenti (Gmelin, 1791) (Bivalvia, Pectinidae)

Abstract

Amusium laurenti is a functional hermaphrodite with well differentiated male and female gonadal areas. The gonadal index varies throughout the year with maximum values occurring in January, March and July, and minimum ones in August and September. Partial spawning (with respect to the individual and the population) occurred from January to February and March to May. The major spawning event coincided with the end of the period during which bottom water temperature increased to temperatures above 26°C (July-August). Subsequently temperature decreased to 22°C, with a period of gonadal restoration and increasing gonadal index. Histological analysis of the gonads correlated with the gonadal index.