Ciclo reproductor de Sardinops sagax (sardina monterrey ), en el Golfo de California

Abstract

The peak reproductive activity of Sardinops sagax was determined from surveys carried out by sampling landings from the commercial fleet operating at the port of Guaymas, Sonora, Mexico, from November to March, 1986. Some discrepancies were found when determining the degree of maturity between that observed when validating with a morphochromatic scale and the one observed with the histological study of the gonads. When validating both methods, it became evident that there was a great deal of difficulty to recognize some of the development stages. Commonly, large differences were found when comparing the relative frequencies of the maturity stages determined by one method or the other. Also, we determ a mistake in the sex proportion. The range of minimum maturity size varied between 125-130 mm and the minimum size with post-ovulatory follicles ranged between 130-135 mm. The critical size was determined by means of the probability analysis of Miller-Tainter and was fixed at 146 y 150 mm, thus coinciding with the mi¬nimum size ruled fro the purpose of commercial fishery. The proportion of catches below the minimum ruled size is presented on a monthly basis; the global proportion for the two fishing seasons was 54.5 %. Also presented and a discussion is made on the causes of this phenomenon and its posible effect on recruitment. When following the sexual maturity by fishing area, a pattern of distribution appears which is consistent with seasonal temperature variations in the mid region of the Gulf of California.