Aspects on the reproductive biology of the Western Mediterranean anchovy from the coasts of Málaga (Alboran Sea)
Ana Giraldez, Rogelio Abad

The reproductive cycle of the anchovy (Engraulis encrasicolus L.) from the purse seine fishing fleet of Málaga (Alboran Sea) has been studied. This analysis was based on the temporal evolution of gonadosomatic index, condition factor, annual size-weight relation, sex ratio, and size at first maturity. The results showed that the anchovy reaches first maturity at 11 cm, although showing inter-annual variations. Size-weight relationship, log-linearized, showed significant differences in relation to sex, and yearly differences within the same sex. Three annual peaks were observed with respect to condition factor. Since the existence of three primary production annual peaks have been described for the Western Mediterranean, the evolution of this factor could be more related to food availability than the reproductive cycle. Spawning occurred in spring and summer, with yearly variations. Mean gonadosomatic indexes were significantly correlated with the mean monthly sea surface temperatures. This relation increased when the temperature data came from the preceeding month. Sex ratios (yearly and monthly) were slightly different from the 1: I ratio, where the females clearly predominated.

Keywords: Reproduction, gonadosomatic index, condition factor, sex ratio, Engraulis encrasicolus, Alboran Sea, Western Mediterranean.
Contents of this volume Sci. Mar. 59(1) : 15-23 Back PDF
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