ANNUAL REPRODUCTIVE-CYCLE OF MILKFISH, CHANOS-CHANOS FORSKAL, IN HAWAIIAN WATERS

The monthly mean values of gonadosomatic index (GSI) over a continuous 36-month period show that the population of milkfish, C.chanos Forskal, in Hawaiian waters has a short breeding season between June and August. In these months, the GSIs of the mature individual males are between 3.19 and 5.36%, and of the mature individual females between 7.07 and 9.76%. These figures plus histological data suggest a synchronous spawning behavior for the species. Mature oocytes (stage III) are larger than 0.7 mm in diameter, which increases to about 1.2 mm at the time of ovulation and about 1.35 mm at the time of spawning. © 1979.