The effect of dietary hydrolysed fish protein concentrate on the survival and growth of juvenile Dover sole, Solea solea (L.), during and after weaning

The growth and survival of 290 mg sole, Solea solea (L.,), during and after weaning onto diets containing varying amounts of hydrolysed fish protein concentrate (HFPC) were determined. Survival ranged between 75.5% and 42.5% (91% with a control diet containing polychaete and mollusc meals) during the weaning period and was positively correlated with the level of HFPC in the weaning diet, After weaning, when the fish were approximate to 940 mg in weight, no significant correlation was found between growth rate and the level of HFPC in the diet over a period of 22 days. Diet digestibility and its importance during weaning is discussed in relation to the digestive physiology of sole. Weaned sole were fed exclusively on a formulated diet in a sand-free tank. at an average temperature of 16.5 degrees C for an Is-month period, achieving a final average weight of 133.1 g +/- 40.1 SD (217.5 mm +/- 19.1 SD).