THE EFFECTS OF SURIMI AND PELLETED DIETS ON THE LABORATORY SURVIVAL, GROWTH, AND FEEDING RATE OF THE CUTTLEFISH SEPIA-OFFICIALIS L

The effects of feeding a prepared surimi diet (fish-based) and a prepa red pelleted diet (shrimp-based) on the survival, growth and feeding r ate of the cuttlefish Sepia officinalis L. were evaluated during a 45- day experiment. One hundred and twenty juveniles of laboratory culture d cuttlefish (74.5 +/- 12.36 g) were divided into three treatments and were fed thawed shrimp (control), pellets or surimi. Survival rates o n these diets were 95.0%, 67.5% and 22.5%, respectively. Preliminary d ata indicated that the low survival of cuttlefish fed surimi may have been caused by low levels of copper in their blood (131 vs 244 mug/ml) since copper is required for their respiratory blood pigment, hemocya nin. Instantaneous growth rates were 2.71% body weight BW/day for cutt lefish fed raw shrimp, 0.33% BW/day for cuttlefish fed pellets, and 0. 54% BW/day for cuttlefish fed surimi. The feeding rate of cuttlefish f ed shrimp was high (6-8% BW/day). The feeding rate on pellets increase d with time (from < 1 to 3% BW/day) but never reached the level for ra w shrimp. The feeding rate on surimi increased to equal the rate for r aw shrimp during days 1-30 (8 to 9% BW/day) and thereafter decreased ( < 4% BW/day). In conclusion, there was a major distinction between the palatability of a prepared diet and the ability of that diet to suppo rt growth. Surimi was highly palatable but resulted in poor survival, suggesting low nutritional quality. In contrast, pellets were less pal atable but produced maintenance growth. Development of practical surim i diets will require supplementation of the surimi with soluble micro- and macronutrients.