Original scientific paper
Sex ratio and male maturity for the shortfin Mako shark Isurus oxyrinchus Rafinesque, 1810 in the Moroccan Central Atlantic Coast
2022, 80 (2) p. 0-0
Jihade ALAHYENE, Brahim CHIAHOU, Hammou EL HABOUZ, Abdelbasset BEN-BANI
Abstract
The study of the reproductive biology of the Mako shark Isurus Oxyrinchus Rafinesque, 1810 is carried out through commercial catches of artisanal boats that are active in the Moroccan Central Atlantic coast and landing at the Sidi Ifni Port, for the period from October 2017 to August 2019. A total of 1690 individuals was examined, including 846 females and 844 males. As a result, the overall sex-ratio of Mako sharks I. oxyrinchus tends towards equilibrium. The monthly sex-ratio trend in Mako shark shows that males are abundant compared to females in Winter. While in Autumn and Spring; it is the females that we meet more. For the remainder of the years, the sex ratio tends to balance, with a slight predominance of males. Three stages of the maturity scale were found. The juvenile male individuals with a rate of (50%) were mostly encountered during the study, followed by adolescents (32%), and adults (18%). The size at the first sexual maturity in the male Mako shark was estimated at 180cm to 187.5cm in total length corresponding to an estimated age of 6 years.
Keywords
Isurus Oxyrinchus, Sex-ratio, Maturity Stage, Size at Maturity, Morocco