Effect of temperature and feeding rate on the growth and survival of earlyand mid-stage phyllosomas of the spiny lobster Jasus edwardsii

Stage I J. edwardsii larvae that had hatched from embryos held at one of th ree temperatures were reared at 12 degrees C to 24 degrees C and fed 2-3 mm brine shrimps. Larvae reared at 24 degrees, 21 degrees, 18 degrees, 15 deg rees and 12 degrees C moulted to Stage II after 7, 8, 11, 17 and 33 days re spectively. Larvae from 18 degrees and 15 degrees C embryos reared at 24 de grees C had 40% and 100% survival respectively. Larvae reared at 12 degrees C had 10-15% survival. Stages II, IV, VI and VIII larvae were reared at three temperatures and fed 4, 8, 12, 16, 24 or 36 brine shrimp per day. At optimum feeding levels and at 24 degrees, 21 degrees and 18 degrees C, Stage II larvae moulted after 6, 8 and 11 days respectively, Stage IV after 9, 10 and 12 days, Stage VI a fter 12, 14 and 17 days and Stage VIII after 18, 21 and 25 days. Survival w as generally >70% but at 24 degrees C when fed >16 brine shrimp survival wa s <40%. For all stages, consumption rates increased but total consumption d ecreased with increasing temperature. For Stages II, IV, VI and VIII the in termoult period increased as the brine shrimp ration reduced. Larvae were s uccessfully reared up to Stage VI similar to 25% faster at 21 degrees than at 18 degrees C.