Reproductive biology of the Mediterranean green crab, Carcinus aestuarii Nardo, 1847 (Crustacea: Portunidae), in the Gulf of Gabes (Tunisia, Central Mediterranean)

The reproductive biology of the Mediterranean green crab, Carcinus aestuarii, from the Gulf of Gabes, was investigated monthly between September 2008 and August 2009. This study was motivated by the lack of information on its reproductive parameters in Tunisian waters. Thus, the sex ratio, the reproductive cycle and the size at first sexual maturity were studied in total 1399 individuals (881 females and 518 males) caught monthly from the intertidal zone and the upper sublittoral fringe. The overall samples presented a carapace width (CW) ranged between 22 and 64 mm, giving 37% of males and 63% of females. The proportions of both sexes varied depending on the size and season; the females were predominant in summer and autumn presenting 72.8 and 64.9% of samples. The size at which 50% of the population reached maturity was 34.56 and 43.93 mm CW for females and males, respectively. Seasonal changes in micro- and macroscopic properties of the gonads of both sexes showed that the reproductive activity for both sexes was greatest in autumn and winter with a major peak in October and a minor peak in January. C. aestuarii exhibited a short resting phase that occurred simultaneously in females and males from June to August.