The effects of temperature and diet on the survival, growth and food uptake of aquarium-held postpueruli of the rock lobster Jasus lalandii

Aquaculture of the rock lobster Jasus lalandii has been considered, but is hindered by a paucity of knowledge about conditions that promote yields. This study investigated the influences of temperature and diet on the growth of aquarium-held postpueruli of J. lalandii. First, postpueruli (11.5+/-0.2 mm CL) were exposed to temperatures spanning 12-24 degrees C for a total time period of 77 days, while being given a constant diet of mussel flesh. Under these conditions, intermoult period (IMP) was longest at 12 degrees C (50.6+/-1.2 days) and at 24 degrees C (>57 days), and shortest at 18 degrees C (35.5+/-1.1 days). Growth increments (GI) were large at 12-18 degrees C, smaller at 21 degrees C and negative at 24 degrees C. Survival was 100% at 12-16 degrees C, above which mortalities rose to 70% at 24 degrees C. Food consumption, body mass and condition all peaked at 18 degrees C. Thus, growth was optimal at 18 degrees C, but survival greatest at 12-16 degrees C. Second, diet-controlled experiments examined the effects of three different diets (blue mussel, commercial shrimpfeed or an alternation of the two) on survival, growth (IMP and GI) and food uptake of postpueruli (11.0+/-0.3 mm CL) held at 18 degrees C for a total time period of 77 days. Feeding rate, average growth, body mass and condition were all highest on the mussel diet, and lowest on the shrimpfeed, and the postpueruli consumed more mussel flesh than shrimpfeed. There was little difference in survival of postpueruli subjected to the three diet treatments. A diet of exclusively blue mussel yielded higher growth, body mass, condition and food uptake than a diet of either shrimpfeed alone or an alternation of mussel and shrimpfeed. The postpueruli acclimated well to culture conditions and survived on a diet of artificial pellets, thus showing good potential for mariculture. On the present evidence, greatest returns are likely at 16-18 degrees C and with a diet of mussel flesh.