OVARIC MATURATION CYCLE, FECUNDITY AND MATURITY LENGTH IN MACRURONUS MAGELLANICUS (LÓNNBERG, 1907) OF THE SOUTHERN REGION OF CHILE.

Abstract

The study of the ovary maturation and fecundity on the haketail, Macruronus magellanicus, at the australsouthern coast of Chile (40° - 56“ S.) was carried out. Fishery commercial samples obtained in 1996 and 1997 were used for analysis. The gonad maturation analysis was done by histological slides and macroscopic examination of the ovary; meanwhile, the partial fecundity was assesed by countig of hydrated oocytes with gravimetric method, after be sure that not postovulatory follicles were present in the gonad
samples. Total fecundity was also assesed by counting of oocytes larger than 300 microns in full ripe stage of the ovary. The fish length at the first sexual maturity was determined from the logistic function during the peak of the spawning season. The macroscopic and microscopic analysis indicated that haketail showed a model syncronic spawning with a maturation cycle starting at may (late fall), reaching the peak at july (early winter) and followed by a short spawning in august (middle winter) that can in some case last until september (late winter). The partial fecundity reached an average of 243.743 ± 155.557 oocytes in fish between 770 and 2.700 g; meanwhile, the relative fecundity was 188 ±83 with range of 65 y 363 oocytes considering the partial fecundity. The linear equation was the best fitted model for the relationship between total weigth-partial fecundity and total lenght-partial fecundity.