Food intake and growth in the Moses perch, Lutjanus russelli (Bleeker), with reference to predation on penaeid prawns |
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Authors: | R. L. Smith,J. P. Salini,&dagger S. J. M. Blaber,&dagger |
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Affiliation: | Institute of Marine Science and Department of Biology and Wildlife, University of Alaska, Fairbanks, Alaska 99775, U.S.A.;CSIRO Division of Fisheries, Marine Laboratories, P.O. Box 120, Cleveland, Qld4163, Australia |
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Abstract: | Juvenile Moses perch were fed various rations of penaeid prawn and pilchard foods at 26.4 and 28.7° C to elucidate feeding–growth relationships. Maintenance rations amounted to 5.0 and 3.8% of body weight per day (BW day–1) on prawn and pilchard diets, respectively, at 26.4° C and 4.5% BW day 1 for prawn at 28.7° C. This apparent reduction in maintenance ration at higher temperature is probably due to reduction in activity levels. Starvation weight loss, an indicator of resting metabolic rate, increased with temperature and exhibited a Q10 of 2.0 to 2.4. Fish fed ad libitum once or twice per day at 26.4° C grew at 1.1 % BW day–1 and ingested about 9% of their BW day–1. At 28.7° C fish ingested about 8% of their BW day–1 and grew 1 .0% BW day–1. These growth rates are comparable to those of similar sized lutjanids in the wild. Since prawns comprise 64% of the diet of Moses perch in northern Australia, this level of consumption would require about 6% BW day–1 of prawns. The relevance of these findings to the assessment of predator impact on prawns in Australian estuaries is discussed. |
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Keywords: | Lutjanus russelli food growth predation prawns |
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