Effects of water temperature on protein synthesis and protein growth in juvenile Atlantic wolffish (Anarhichas lupus)

The effects of water temperature (5, 8, 11, and 14 degrees C) on the fractional rate (percent per day) of protein consumption (k(r)) and on white muscle and whole-body fractional rates of protein synthesis (k(s)), protein growth (k(g)), and growth efficiency (PPV, growth/consumption; k(g)/k(s), growth/synthesis) of juvenile Atlantic wolffish (Anarhichas lupus) (initial body weight 26 g) were studied. Rates of protein consumption and white muscle and whole-body protein synthesis increased in a linear fashion between 5 and 14 degrees C. In contrast, the relationships between temperature and white muscle and whole-body protein growth, protein growth efficiency (PPV) and protein synthesis retention efficiency (k(g)/k(s)) were parabolic. The results indicated that the optimum water temperatures for growth (T-opt.G) and growth efficiency (T-opt.GE) were 10-11 and 9-10 degrees C, respectively The maximum white muscle and whole-body protein growth rates recorded at T-opt.G were 0.9 and 0.7 %.day(-1), respectively. At T-opt.GE, the maximum white muscle and whole-body PPV values were 28 and 34%, respectively, and k(g)/k(s) values were 92 and 51%, respectively. The growth performance data for juvenile Atlantic wolffish in comparison with published data for salmonids (rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar)) at 9-11 degrees C further highlight its suitability as an alternative species for cold-water aquaculture in northern Europe and Atlantic Canada.