The effect of temperature on survival, growth, feeding and metabolic activity of the southern rock lobster, Jasus edwardsii

Ž . This study investigated the effect of temperature 18, 20, 22 and 248C on growth, feeding and metabolism of post-puerulus lobsters as part of a larger study of the culture potential of farming Ž . the southern rock lobster, Jasus edwardsii. There was no significant difference P)0.05 in the Ž . Ž . specific growth rates SGR at 18, 20 or 228C; however, growth decreased significantly P-0.05 Ž 2 at 248C. The growth response was described by a quadratic regression SGRsy0.031T q 2 . 1.261Ty10.884, r s0.77 , which predicted the optimum temperature for growth to be 20.68C. Lobsters held at 228C had smaller intermoult periods than lobsters at 188C; however, a decreased moult increment at 228C meant that growth rate did not increase at that temperature. The decreased growth at 248C compared to 228C was evidenced by a longer intermoult period. Temperature affected survival of lobsters, with survival at 248C being significantly lower Ž . Ž . P-0.05 than at 188C. There were no significant differences P)0.05 in survival at 18, 20 or Ž . 228C. The response of feed conversion ratio FCR to temperature was described by a quadratic Ž 2 2 . regression FCRs0.011T y0.434Tq5.231, r s0.995 , which suggested that the optimum Ž . temperature for feed conversion was 19.38C. Oxygen consumption rates M increased with O2 increasing temperatures between 188C and 228C and declined at 248C; whilst total ammonia Ž . nitrogen TAN excretion increased with increasing temperature. The relationships were described 2 Ž 2 . by regression equations: M sy0.044T q1.91Ty18.553 r s1.0 ; TANs0.127Ty1.174 O2 Ž 2 . r s0.91 . A temperature of 248C appears to be above the upper thermal tolerance of juvenile J. ) Corresponding author. Tel.: q61-03-62-277-273; fax: q61-03-62-277-298. Ž . E-mail address: [email protected] C.W. Thomas . 0044-8486r00r$ see front matter q 2000 Elsevier Science B.V. All rights reserved. Ž . PII: S0044-8486 99 00341-5 ( ) C.W. Thomas et al.rAquaculture 185 2000 73–84 74 Ž . edwardsii. Lobsters held at this temperature showed reduced survival compared to those at 188C , Ž . reduced growth compared to those at 228C and appeared to be suffering from respiratory stress Ž . moult-related mortalities, low Q between 228C and 248C . Overall, the results indicate that 10 juvenile J. edwardsii can be cultured at 228C without adversely affecting their growth, survival or feed efficiency with optimal temperature range between 19 and 218C. q 2000 Elsevier Science B.V. All rights reserved.