Madurez sexual y fecundidad del lenguado (Hippoglossina macrops Steindachner) (Pisces, Bothidae)

Abstract

The reproductive cycle and fecundity of Hippoglossina macrops Steindachner from Valparaiso, Chile, were determined by means of monthly catches aboard a bottom otter trawling ship throughout a year. Total length, body weight, sex, sexual maturity stage, frecuency distribution of oocyte diameters and fecundity were determined for a each fish. A large stock of small oocytes measuring less than 220 microns of diameter and a number of size modes of large oocytes in different stages of vitellogenesis were observed in the ovaries. Atresic oocytes with an oil globule, remnantes of a recent spawn, were detected in maturing and sexually ripe gonads. Fecundity varied from 3,000 to 140,000 oocytes, showing a direct relation with body weight and a power relation with total length. The standard error of the estimate for the relation of fecundity versus body weight was 14.932 expressed in thousands of oocytes. The relation between total length and body weight corresponded to a power curve. The analysis of the sexual maturity stages showed that the minimum total length a t first sexual maturity in female fish was 26 cm. All the males caught were sexually inmature. Females in different stages of gonadic development were obtained simultaneously in all months. The period of maximum reproductive activity was found to be from August to November. The intensity of spawning diminished from December to March, reaching its lowest level from April to July. No resting period was detected in the reproductive activity of the spawning stock. From the results obtained, it is concluded that Hippoglossina macrops has an heterochronal spawning cind that maturing and ripe males are spatially segregated from females. 69% of fish caught by the o tte r trawling fishing ship were below the minimum size a t first sexual maturity calculated for females.