Description, distribution and abundance of late larval stages of the Scyllaridae (slipper lobsters) in the south-eastern Indian Ocean

Abstract

Plankton samples from the south-eastern Indian Ocean between 25º30's. and 35º00'S. and from the Western Australian coast out to 99º 00'E., showed the presence of several species in three genera of the Scyllaridae; Scyllarides sp. a; Scyllarus demani; Scyllarus bicuspidatus; Scyllarus spp. a, b, and c; Ibacus peronii and Ibacus sp, a. The final (gilled) phyllosoma and nisto stages of previously undescribed species are described. A generic key to the final phyllosoma of the Palinuridae, Scyllaridae and Synaxidae recorded from the southern Indian Ocean is presented.

The distribution of the catches of the phyllosoma of Scyllarus bicuspidatus, Scyllarus sp. b, Ibacus peronii and Scyllarides sp. a and data on the seasonal catches of all scyllarid species are presented.

The phyllosoma of S. bicuspidatus undergo diel migrations. Early-stage densities peak at depths of 40-80 m during the day, and mid and late stages peak at 80-100 m. At night the early stages are found at the surface, independent of moonlight intensity. Mid and late stages peak at the surface only on moonless nights. On moonlit nights the density of mid and late stages peak at 15-25 m depth.