The effect of temperature and fish size on growth of juvenile lumpfish (Cyclopterus lumpus L.)

Abstract The lumpfish ( Cyclopterus lumpus L.) has recently become relevant for aquaculture due to its appetite for the ectoparasitic copepod, the sea louse ( Lepeophtherius salmonis Kroyer). In order to determine the effect of temperature on growth properties of juvenile lumpfish, two size groups (6.2 g, S.E. ± 0.1 and 26.5 g, S.E. ± 0.6) were compared in terms of temperature- and size-related growth at 4, 7, 10, 13, 16 °C and varying ambient temperature. The overall highest growth rates were observed for fish − 1 ), and declined stepwise with decreasing temperature. Only a modest response to temperature was observed for large fish > 120 g. Size rank correlations increased with increasing body weight. The results presented in this study suggest that optimum temperatures for growth (T optSGR ) decreased with increasing fish size from 15.7 °C for 11.0–20.0 g fish, 16.1 °C for 20.0–40.0 g fish, 13.1 °C for 100.0–110.0 g fish, to 8.9 °C for 120.0–200.0 g fish.