RT Journal Article SR 00 A1 Courtney, A.J. A1 Dredge, M.C.L. A1 Masel, J.M. T1 Reproductive Biology and Spawning Periodicity of Endeavour Shrimps Metapenaeus endeavouri (Schmitt, 1926) and Metapenaeus ensis (de Haan, 1850) from a Central Queensland (Australia) Fishery JF Asian Fisheries Science YR 1989 FD 1989 VO 3 SP 133 OP 147 K1 Spawning periodicity; endeavour shrimps; Metapenaeus endeavouri; Metapenaeus ensis. AB Metapenaeus endeavouri and M. ensis from coastal trawl fishing grounds off central Queensland, Australia, have marked seasonal reproductive cycles. Female M. endeavouri grew to a larger size than female M. ensis and occurred over a wider range of sites and depths. Although M. ensis was geographically restricted in distribution to only the shallowest sites it was highly abundant. Mating activity in these open thelycum species, indicated by the presence or absence of a spermatophore, was relatively low and highly seasonal compared with closed thelyeum shrimps. Seasonal variation in spermatophore insemination can be used as an independent technique to study spawning periodicity in open thelycum shrimps. Data strongly suggest an inshore movement of M. endeavouri to mature and spawn. This differs from most concepts of Penaeus species life cycles, but is consistent with the estuarine significance in the life cycle of Metapenaeus species. Monthly population fecundity indices suggest summer spawning for both species, which contrasts with the winter spawning of other shrimps from the same multispecies fishery. NO Reproduced with permission from the Asian Fisheries Society. PB Asian Fisheries Society LK http://era.daf.qld.gov.au/id/eprint/466/