Effect of protein source on growth and energetic reserves of juveniles of the commercial crayfish Cherax quadricarinatus

GUTIÉRREZ, M.L.; RODRÍGUEZ, E.M.

Coquimbo

Congreso; The Crustacean Society mid-year meeting; 2007

The Crustacean Society

Four isoproteic (35%) and isocaloric (10% lipids and 20% carbohydrates) were assayed on early juveniles (initial weight: 23.793 ± 0.083 mg) of the crayfish C. quadricarinatus. These diets were (w/w percentage in the diet is indicated): SOY (65 %, as expeller), FISH (51 %, as flour), SQUID (63  %, as hydrolyzed) and KRILL (55  %, as flour). Survival, weight gain measured as ((Wax)/Wig) x 100, and specific growth rate measured as ((ln Wax – ln Wig)/ t) x 100, were determined (Wax: body weight at time x, Wig: initial weight, and t: time in days). After 90 days, the content of protein, glycogen, lipids and cholesterol was determined in both the hepatopancreas and muscle of all survival animals. Best survival was observed in both FISH and KRILL diets (a mean of 68 %), following SOY (49.2 %), and finally SQUID diet (27.2 %). Both weight gain and specific growth rate were similar among diets, with the exception of SQUID, which showed values significantly (p<0.05) lower than the remaining diets. Although a higher percentage of protein was observed in the hepatopancreas of animals fed on KRILL diet, those crayfish fed on SOY diet showed higher values of lipids and cholesterol. A similar pattern was also observed in muscle, where SOY yielded the highest values for all of the analyzed organic compounds.