ANALYSIS OF OOCYTE DEVELOPMENT AND POTENTIAL FECUNDITY OF THE SQUID LOLIGO-VULGARIS FROM THE WATERS OF SOUTHERN PORTUGAL

This study constitutes a first approach of the use of a stereological method for estimating potential fecundity in cephalopods. Squid sample s were taken in two regions from the south coast of Portugal. In Olhao , commercial trawlers provided mainly immature squid during winter. In Quarteira, a summertime traditional jigg fishery provided maturing an d mature squid, which were used in the fecundity estimates. A total of 38 female squid, Loligo vulgaris (Cephalopoda: Loliginidae), from all maturity stages were analysed. The results revealed that: (1) the dev elopment of the ovaries is monocyclic and the oocyte growth and develo pment is asynchronous; (2) oogenesis proceeds in six histological stag es, showing statistically different oocyte maximum diameters; and (3) the best estimate of potential fecundity seems to be obtained by count ing all oocytes in the ovaries of the mature females in maturity stage IV.