Atlantic cod Gadus morhua larvae reached four‐fold (at low larval density) to 11 fold higher body mass (high larval density) at 50 days post hatch (dph) when fed zooplankton rather than enriched rotifers. A short period (22–36 dph) of dietary change affected larval growth positively if changed from enriched rotifers to natural zooplankton and negatively if prey type changed vice versa . Overall survival did not differ between...

Short‐term environmental manipulations during the early juvenile stage have a large impact on harvesting size of Atlantic cod Gadus morhua nearly 3 years later. A group of juvenile Atlantic cod (initial mass 9·5 g) were reared for 3 months under simulated natural photoperiod or continuous light, and a range of temperatures (7, 10, 13 and 16° C, and a group called T‐step, i.e. with temperature reduced successively from 16 to 13...

The growth properties of juvenile spotted wolffish Anarhichas minor reared at 4, 6, 8 and 12° C, and a group reared under ‘temperature steps’, (T‐step) i.e . with temperature reduced successively from 12 to 9 and 6° C were investigated. Growth rate and feed efficiency ration was significantly influenced by temperature and fish size. Overall growth rate was highest at 6° C (0·68% day −1 ) and lowest at 12° C (0·48% day −1 ), wh...

Salinity significantly influenced growth and RNA: DNA ratios in three populations (Iceland. Norway and France) of juvenile turbot Scophthalmus maximus as these variables were higher at 15 than at 33.5‰ salinity. Furthermore, growth and RNA: DNA ratios of the two high latitude populations (Iceland and Norway) were higher than those of the low latitude population (France): the Norwegian and the Icelandic populations had RNA: DNA...

Food conversion efficiency and growth of juvenile turbot Scophthalmus maximus , reared under temperatures of 14, 18 and 22° C, were found to be higher in one experiment (7–70 g fish) in a higher latitude (Norway) strain than lower latitude (France and Scotland) strains. In a second study (20–150 g fish), food intake, food conversion efficiency and growth were higher in higher latitude (Iceland and Norway) compared with a lower...

Growth performance of a high latitude (Norway) population of juvenile turbot Scophthalmus maximus , was superior to that of two other lower latitude populations (Scotland, France) especially at 18° and 22° C. Overall these results lend some support to the hypothesis of countergradient variation in growth. The Norwegian population had the highest estimated temperature optimum for growth ( T opt.G , ±S.E.) (23·0±0·9°C) and food...