Larvae of S. semifasciatus, S. queenslandicus, and S. commerson were dissected for gut-content analysis. S. semifasciatus larvae feed almost exclusively on larval fish, and S. queenslandicus and S. commerson larvae feed almost exclusively on larval fish and larvaceans. S. queenslandicus larvae exhibit a distinct ontogenetic change in diet, with larvaceans decreasing and larval fish increasing in dietary importance with growth. The maximum size of prey consumed by S. semifasciatus and S. queenslandicus increases with growth.

Descriptions of the Nisto Stage of Scyllarus demaniHolthuis, Two Unidentified Scyllarus Species, and the Juvenile of Scyllarus martensii Pfeffer (Crustacea : Decapoda : Scyllaridae), Reared in the Laboratory; and Behavioural Observations of the Nistos of S. demani, S. martensii and Thenus orientalis (Lund) Live final-stage phyllosoma larvae of 7. orientalis, S. martensii, S. demani, and an unidentified specimen, Scyllarus sp. A, were obtained from the mid-shelf region of the Great Barrier Reef. While held in the laboratory, larvae of all species metamorphosed to the subsequent, nisto, stage; the nisto of S. martensii developed further to the first juvenile phase. An additional, nisto, Scyllarus sp. B, obtained in a plankton sample, remains unidentified. In this paper, the nistos of S. demani, Scyllarus sp. A , and Scyllarus sp. B, and the juvenile of S. martensii are described; and behavioural observations of live material, including nistos of T. orientalis, are discussed.Fig. 4. Scyllarus sp. B nisto. (a) Dorsal view. (b) Ventral view of antenna. (c) Lateral view of thorax and abdomen. ( d ) Thoracic sternum. (e) Pleopod of second abdominal segment. B. M. Barnett et al. Description of Nistos of Scyllarus spp.

The reproduction and development of two plotosid catfishes, N. ater and N. hyrtlii, were investigated in a seasonal tributary of the Ross River, northern Queensland. The fishes were observed to move upstream to spawn during monsoonal flooding. Their mating behaviour, embryology and larval development are described. The adaptive significance of a flood-spawning strategy is discussed in relation to food availability, predation, and aeration in seasonal tropical streams.

Samples of macrozooplankton collected from the shelf area of the Great Banier Reef (between 18'35's. and 19'10's. and 146"30'E. and 147"OO'E.) contained phyliosomes of several different species of scyllarid lobster, including those of T, orientalis. Four larval stages of T. orientalis are described from the plankton and are related to laboratory-reared specimens of the first stage and of the postlarval nisto. An attempt is made to clarify discrepancies in the existing literature relating to descriptions of larval T. orzentalis.

The larval developmental stages of five of the eight species of Psettodes and Pseudorhombus known from the shelf waters of the central Great Barrier Reef are described and illustrated. The species treated include Psettodes erumei (3.3-13.0 mm body length, BL), Pseudorhombus arsius (2.9-11.5 mm BL), P. elevatus (3.4-100 mm BL), P. diplospilus (4.2-12.6 mm BL) and P. spinosus (2.5-12.7 mm BL). Meristic characters were reliable for identifying larvae only if full complements of these characters had been acquired. Smaller larvae were identified on the basis of pigmentation and head spination or spinulation patterns. The settling sizes of these larvae were estimated based on the stage of eye migration.