Sex Ratio and Male Maturity for Shortfin Mako Shark in the Moroccan Central Atlantic Coast

Abstract

Abstract The study on the reproductive biology of shortfin mako shark is carried out through the commercial catches from artisanal boats active on the Moroccan Central Atlantic coast and landed in Sidi Ifni Port, for the period between October 2017 and August 2019. A total of 1690 individuals were examined, including 846 females and 844 males. As a result, the overall sex ratio of shortfin mako sharks tends towards equilibrium. The monthly sex ratio in shortfin mako sharks shows that males are more abundant compared to females in winter. In autumn and spring, we encounter more females. For the remainder of the year, the sex ratio tends to be balanced, with a slight predominance of males. Three stages of the maturity scale were found. Juvenile males with a rate of 50% were most frequently encountered during the study, followed by subadults with a rate of 32% and adults with a rate of 18%. The size at first sexual maturity of the male shortfin mako shark was estimated to be between 180 cm and 200 cm in total length, corresponding to an estimated age of 6 years.