Feeding Artemia and shellfish to phyllosoma larvae of southern rock lobster (Jasus edwardsii)

Abstract

Newly-hatched phyllosoma larvae from southern rock lobster (Jasus edwardsii) were grown in culture vessels containing 10 l sea water in a flow-through system at 18 degrees C and fed diets of Artemia sp. and shellfish. The survival and growth of larvae to Stage II was higher when fed ongrown (1.5 mm long) Artemia enriched with Isochrysis galbana (Tahitian strain) at 3 ml-1 compared to those fed pieces (0.5-1 mm) of blue mussel (Mytilus edulis planulatus), clam (Katelesia scalarina) or Pacific oyster (Crassostrea gigas) at 0.08 pieces ml-1. There were no differences in survival, size or intermoult interval for newly-hatched larvae grown to Stage III when fed ongrown Artemia only at densities of 1.5, 3 or 6 ml-1 or for Stage III larvae grown to Stage VI when fed ongrown Artemia at densities of 1.5, 3 or 6 ml-1 plus mussel (0.04 pieces ml-1). Stage VI larvae fed ongrown Artemia plus mussel (0.08 pieces ml-1) were larger by instar 10 than larvae fed mussel only (0.08 or 0.16 pieces ml-1). Lower survival became apparent for the mussel-only treatments 205 days after hatch (at Stages IX or X). The pattern of moulting became progressively less synchronised with each successive stage and instar, so that after instar 11 (about Stage IX), it was difficult to discern discrete peaks in the moulting pattern. The first larva reached Stage XI 288 days after hatch. The size of larvae and duration to successive moults, but not survival, were influenced by parent of origin indicating the importance of selection of broodstock in hatchery rearing.