REPRODUCTIVE CYCLE OF THE PACIFIC SARDINE, SARDINOPS SAGAX MUSICA (GIRARD, 1854) FROM THE FISHERY AREA OF TALCAHUANO, CHILE (1983-1984)

Abstract

This report describes the spawning cycle of the Pacific sardine Sardinopssagax música (Girard, 1854) during 1983-1984, in the Talcahuano fishery area (36°41'S; 73°06'W), using gonadic histological analysis. Information on gonosomatic índex and the presence of eggs and larvae in the plankton are also used. The results show Pacific sardine to be a serial spawner with continuous breeding throughout the year, and two peaks of reproductive activity-a main peak during winter and early spring (june to september), and a secondary peak in february. The implications of this two spawning peaks, and an índex of larval survival Índex in relation to environmental biotic and abiotic conditions are discussed. First maturity sizes were found to be 29.5 cm total lenglh for males and 30.0 cm for females, which aproximately corresponds to 5 year of age. The reproductive cycle in Talcahuano is similar to that found in the north of Chile. This could mean that the Southern stock originated from the northern stock, but the reproductive differences between the both areas (e.g. first maturity size) migth indícate the existence of at least two populations along the Chilean coast.