Observations on Reproduction in the Shortfin Mako Isurus oxyrinchus

Abstract

Ninety one Isurus oxyrinchus were examined from New South Wales Australia. Males attain sexual maturity at 195 cm total length; females mature at 280 cm. Data obtained from gravid and mature non-gravid specimens confirms that I. oxyrinchus is oviphagous. Size at birth is about 70 cm and litter sizes vary from 4 to 16. Parturition off New South Wales probably occurs in November. The length (L)/weight (W) relationship for I. oxyrinchus is described by the equation W = 4.832 x 10-6,L3.