The interaction of temperature and salinity on growth and food conversion in juvenile turbot (Scophthalmus maximus)

A.K. Imsland, A. Foss, S. Gunnarsson, M.H.G. Berntssen, R. FitzGerald, S.W. Bonga, E. v. Ham, G. Nævdal, S.O. Stefansson-2001


Aquaculture, 198 (3-4): 353-367
Abstract:

The effects of temperature and salinity on growth and feed conversion of juvenile turbot (initial mean weight 14 g) were investigated by rearing fish at (mean±SD) 10±0.2°C, 14±0.2°C, 18±0.3°C and 22±0.2°C and 15±0.4ppt, 25±0.4ppt and 33.5±0.1ppt for 3 months. Growth, food consumption, and food conversion efficiency were highest at 15 ppt, and lowest at 33.5 ppt. There was an interactive effect of temperature and salinity at the two highest temperatures (18°C and 22°C) but not at 10°C and 14°C. The optimal temperature for growth (Topt. G) varied with salinity: Topt. G at 33.5ppt was 19.6±0.3°C (±SEM), whereas the Topt. G at 15 ppt was 22.9±1.0°C, and at 25 ppt was 24.7±2.1°C. A similar trend was found for food conversion efficiency (FCE). The optimal temperatures for FCE were 17.4±0.5°C, 17.9±1.0°C and 19.0±0.9°C at 33.5 ppt, 25 ppt and 15 ppt, respectively. Overall, we found the optimal temperature-salinity combination for growth to be 21.8±0.9°C and 18.5±0.8 ppt. The optimal temperature-salinity combination for food conversion efficiency was found to be 18.3±0.6°C and 19.0±1.0 ppt. It is concluded that growth and food conversion efficiency of juvenile turbot can be improved by rearing them at intermediate salinities in the upper temperature range.

(Department of Fisheries and Marine Biology, University of Bergen, High Technology Centre, N-5020 Bergen, Norway, e-mail: alberti@uvs.is)

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