SPINY LOBSTER RECRUITMENT OFF WESTERN-AUSTRALIA

The phyllosoma larval stages of the western rock lobster Panulirus cyg nus are dispersed up to hundreds of kilometers offshore and spend almo st a year in the south eastern Indian Ocean. At the end of this phase, some late-stages have returned to near the continental shelf off West ern Australia and some final stage phyllosomata metamorphose to the pu erulus stage, which then swims across the shelf to settle in the coast al reefs. This paper examines data from a cruise by the FRV SOUTHERN S URVEYOR in September 1991, designed to sample both the sub-surface and surface distributions of the larvae and pueruli of P. cygnus as influ enced by the Leeuwin Current, in an attempt to reserve some of the que stions concerning the location and the stimulus for metamorphosis, as well as the mechanisms of transport of the puerulus across the shelf. Metamorphosis from the final phyllosoma larva to the puerulus stage in FI cygnus was confirmed to occur mainly near the Vicinity of the shel fbreak. However, the stimulus, if it exists, remains unclear. The annu al level of puerulus settlement along the coast of Western Australia i s related to the strength of the Leeuwin Current and settlement is hig her when the current is stronger. Increased mixing of oceanic and shel f waters caused by stronger flows of the Leeuwin Current may provide i ncreased transport of the pueruli of P. cygnus towards the coast there by increasing survival of pueruli to settlement.