comparative effects of long-term hypoxia on growth, feeding and oxygen consumption in juvenile turbot and european sea bass


K. Pichavant, J. person-le-Ruyet, N. Le Bayon, A. Severe, A. Le Roux, G. Bœuf-2001

Journal of Fish Biology, 59(4): 875-883

Abstract:

When juvenile turbot Scophthalmus maximus and sea bass Dicentrarchus labrax were fed to satiation, growth and food intake were depressed under hypoxia (3.2±0.3 and 4.5±0.2mg O2l-1). However, no significant difference in growth was observed between fishes maintained in hypoxia and fed to satiation and fishes reared in normoxia (7.4±0.3mg O2l-1) and fed restricted rations (same food intake of fishes at 3.2mg O2l-1). Routine oxygen consumption of fishes fed to satiation was higher in normoxia than in hypoxia due to the decrease in food intake in the latter. Of the physiological parameters measured, no significant changes were observed in the two species maintained in hypoxia. This study confirms the significant interaction between environmental oxygen concentrations, feeding and growth in fishes. Decrease in food intake could be an indirect mechanism by which prolonged hypoxia reduces growth in turbot and sea bass, and may be a way to reduce energy and thus oxygen demand.

(Laboratoire de Biologie et Physiologie Cellulaires, UFR Sciences et Techniques, Université de Bretagne occidentale, 6 avenue Le Gorgeu, BP 809 29285 Brest Cédex, France. Tel.: +33 02 98 01 72 60; fax: 33 02 98 01 63 11; email:Karine.Pichavant@univ-brest.fr)


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