Growth of juvenile southern rock lobsters, Jasus edwardsii, is influenced by diet and temperature, whilst survival is influenced by diet and tank environment

The growth and survival of juvenile (2-15 g) southern rock lobsters (Jasus edwardsii) were examined under various culture regimes. In Experiment 1, lobsters held at ambient (13-18 degrees C) or 18 degrees C were fed either fresh mussels, a commercial prawn diet or a moist diet. Growth (specific growth rate (SGR) = 1.2-1.32% BW day(-1)), survival (98%) and food conversion ratios (FCR = 1.26-1.29) were significantly better (P < 0.05), and the protein component of the diet best utilised (protein productive value (PPV)= 18.3-19%) (P > 0.05), when the lobsters were fed mussels. There was a significant interaction (P < 0.05) between diet and temperature. Growth at 18 degrees C was significantly higher (P < 0.05) than at ambient, except when lobsters were fed the prawn diet when there were no significant differences (P > 0.05). The high acceptance and good consumption rate of formulated diets is a positive first step in the development of commercial diets for southern rock lobsters. In Experiment 2, lobsters held at ambient (13-18 degrees C) or 18 degrees C were maintained in tanks containing hides, substrates or neither. Hides increased survival (98%, cf. 60-75%) (P > 0.05), although they did not increase growth (P > 0.05) compared to tanks without hides. The provision of a substrate to aid the lobsters in the moulting process did not prevent cannibalism. Lobsters grew significantly faster (P < 0.05) at 18 degrees C (SGR = 1.32% BW day(-1)) than at ambient (1.21% BW day(-1)), with the extra growth explained by a significantly higher (P < 0.05) apparent feed intake. Most mortalities were due to cannibalism of soft-shelled lobsters, suggesting that the design and management of systems will be an important component of mass culturing juvenile J. edwardsii. (C) 2000 Elsevier Science B.V. All rights reserved.