HABITAT USE AND GROWTH OF JUVENILE ORNATE ROCK LOBSTERS, PANULIRUS-ORNATUS (FABRICIUS, 1798), IN TORRES STRAIT, AUSTRALIA

Habitat use and growth of juvenile (8-90 mm carapace length, or CL) or nate rock lobsters, Panulirus ornatus, were described with the aid of information from field surveys in Torres Strait and from a laboratory growth experiment. In north-western Torres Strait, small juveniles (<4 0 mm CL) sheltered in solution holes in the seabed that matched their body size. Most shelters were in limestone pavement and near macroalga e. Larger juveniles sheltered in both solution holes and crevices. Juv eniles were found at all depths sampled (3-21 m), and densities of juv eniles were uniform over this depth range. The average density of juve niles in the study area in 1992-93 was 63 ha(-1). Size distributions o f juveniles sampled during August 1992 to March 1993 showed that early growth was 1.4 mm CL week(-1). A laboratory trial to examine the effe ct of temperature on growth showed that juveniles grew 31% faster at 3 0 degrees C (0.88 mm CL week(-1)) compared with growth at 26 degrees C (0.67 mm CL week(-1)) as a result of shorter moult intervals in large juveniles. Size distributions of juveniles sampled at mid year betwee n 1990 and 1995 showed that 10-20% reach legal size (75 mm CL) about o ne year after settlement.