Mobulid rays are distributed worldwide in tropical and warm temperate waters, and are landed as bycatch in many different fisheries. Five mobulid species (Mobula birostris, M. japanica, M.munkiana, M. tarapacana and M.thurstoni) are currently listed as vulnerable by the IUCN Red List for Threatened Animals for at least part of their geographic distribution. There is a lack of information on mobulid populations, and consequently it is very difficult to determine how the level of exploitation of mobulids in Indonesia may affected their stocks. Data in this study were derived from 409 mobulids that were taken as bycatch of drift gillnet fisheries for the skipjack tuna (Katsuwonus pelamis) and subsequently examined at fish landing sites in Indonesia. Results idenitfied M. japanica and M. tarapacana were the most abundant species represented. The disc width at maturity (DW50) of males, derived from the proportion of males at each size class with fully calcified claspers, ranged from 1538 mm for M. thurstoni to 3752 mm for M. birostris. The very low fecundity of the large and probably long-lived mobulid rays make the stocks of their species particularly susceptible to further increases in fishing.
Year
Journal/Publisher Name
Fisheries Research
Volume (Issue #)
Volume 82
Page #s
65-73
Contact information
Murdoch University, Centre for Fish and Fisheries Research, South Street, Murdoch, WA 6150, Australia
Summary