Reproduction of the ornate rock lobster, Panulirus ornatus (Fabricius), in Papua New Guinea

Abstract

Based on the examination of 26 499 female and 17 666 male specimens, the reproductive biology of P. ornatus is discussed with spatiotemporal reference to the annual breeding migration from northern Torres Strait to the Gulf of Papua. Migration commences generally in August with ovary development, mating and initial oviposition occurring during migration. Larval release normally commences once the migration has terminated on the reefs of the eastern seaboard in the Gulf of Papua. At the conclusion of the migration, marked segregation of the sexes occurs, with males entering shallow water (< 3 m) before females, who frequent deeper water (3-15 m) until their eggs have hatched. During the breeding season (November- April), females produce up to three broods. Fecundity is determined for 33 females in the carapace size range 75.4-121.0 mm. No significant egg loss during incubation was detected, but there was an indication of a reduction in the size of each subsequent brood. There appears to be a high post-spawning mortality of migratory lobsters. It is likely that the Gulf of Papua is the major source of larval recruitment in the western Coral Sea, including the east coast of Queensland and Torres Strait.