Growth, development and behaviour of artificially reared larval Pagrus auratus (Bloch & Schneider, 1801) (Sparidae)

Abstract

Pagrus auratus eggs were obtained from wild broodstock with naturally and artificially ovulated fish. Larvae were cultured for periods of up to 1 month on a diet of marine rotifers, Brachionus plicatilis. Small yolk-sac larvae hatched without functional eyes, mouth or digestive tract and for 3 days spent long periods at rest. Growth was initially rapid but slowed by 3 days as yolk reserves were nearing depletion. By Days 4-5, the mouth had opened, eyes were pigmented, yolk was depleted, and a rudimentary gut had formed. Larvae were now able to maintain a horizontal swimming mode and were actively searching for and attacking prey. First-feeding was observed in some larvae. Growth was retarded during the transition from endogenous to exogenous nutrition and then increased, probably as feeding proficiency improved with experience. Larvae starved from hatching did not survive for longer than 8 days.