COMPARATIVE MORPHOLOGY OF THE MOUTHPARTS AND FOREGUT OF THE FINAL-STAGE PHYLLOSOMA, PUERULUS, AND POSTPUERULUS OF THE ROCK LOBSTER JASUS EDWARDSII (DECAPODA: PALINURIDAE)

The gross morphology and fine structure of the mouthparts and foregut of the rock lobster Jasus edwardsii were studied in its late larval and early juvenile stages. The stage-XI phyllosoma has third maxillipeds with specialized setae, second maxillipeds and first maxillae with strong setae, mandibles with well-developed molar and canine-like processes and teeth, and a foregut with well-developed grooves and brushes but no gastric teeth. The first-molt juvenile has third and second maxillipeds and first maxillae with rows or tufts of numerous strong setae, wellcalcified mandibles with strong molar and incisor processes, and a foregut with well-developed ossicles, grooves, brushes, and strong gastric teeth. In contrast, the puerulus has maxillipeds and maxillae with only small numbers of setae, uncalcified mandibles with a rudimentary incisor, and a foregut with a small number of ossicles and setae, and rudimentary lateral teeth. These observations suggest that the late-stage phyllosoma of J. edwardsii feeds primarily on large, soft materials and the early postpuerulus on hard, as well as soft, materials. In contrast, the puerulus probably does not feed during some or all of its existence, and any feeding is on small, soft materials. Use of nutrients stored in the digestive gland is one possible way that the puerulus could meet its energy requirements.