Reproductive biology of the smooth-hound shark Mustelus mustelus (L.) in the Gulf of Gabes (south-central Mediterranean Sea)

The reproductive biology of the smooth-hound shark Mustelus mustelus was studied in the Gulf of Gabes (southern Tunisia). Females were found to mature between 1075 and 1230 mm total length (L-T) whereas males matured between 880 and 1120 mm L-T. The L-T at which 50% of the population reached maturity was 971 and 1172 mm for males and females, respectively. Male gonads were symmetrical in terms of mass and both functional, whereas in females only the right ovary was functional. The seasonal changes in the oocytes and testes development, embryo length and the occurrence of near-term and post-partum females showed that this species displayed a clearly defined annual reproductive cycle with parturition occurring during late April and early May, after a gestation period of 10-11 months. Mating took place during May and early June and fertilization occurred from early June to early July. The embryo sex ratio was not significantly different from unity. Litter size varied from four to 18 embryos and was positively correlated with maternal L-T. The young were born with a L-T of 340-420 mm. (c) 2008 The Authors Journal compilation (c) 2008 The Fisheries Society of the British Isles.