Reproduction of the blue-spotted maskray Neotrygon kuhlii (Myliobatoidei: Dasyatidae) in south-east Queensland, Australia.

ABSTRACT

This study examined the reproduction and population structure of the blue-spotted maskray Neotrygon kuhlii within Moreton Bay, a subtropical embayment in south-east Queensland, Australia. Mean sizes at maturity were 314 mm disc width (W(D)) in females (n = 140, 115-465 mm W(D)) and 294 mm W(D) in males (n = 123, 129-381 mm W(D)). Female N. kuhlii had a synchronous annual reproductive cycle, with one litter of one to three pups (mean +/-s.d. 1.67 +/- 0.71) produced per year. Mating behaviours were observed in October and November, and ovulation occurred early in the Austral summer, overlapping with the start of embryonic development. Gestation took c. 4 months with parturition occurring in late February and March. Size at birth was 115-170 mm W(D). The population showed a significant female bias, particularly in larger size classes. Tagging studies produced a total recapture rate of 16.1% and indicated that N. kuhlii were site resident for up to 1081 days.