Catch up and compensatory growth in juveniles of the redclaw Cherax quadricarinatus exposed to different diets.

LIANE STUMPF; TROPEA CAROLINA; CASTILLO DÍAZ FERNANDO; LÓPEZ GRECO LAURA S.

San José

Congreso; TCS-ALCARCINUS Summer Meeting, Costa Rica 2013; 2013

Compensatory and catch up growth have been scarcely studied in crustaceans although they are considered useful tools to improve fish culture. The effect of two diets on compensatory and catch up growth in juveniles of Cherax quadricarinatus after cyclic feeding followed by continuous feeding, was evaluated. Diet A consisted of 49% crude protein, 5% crude lipid, 9% ash and 6% moisture, while Diet B consisted of 38% crude protein, 6% crude lipid, 16% ash and 4% moisture. For both diets juveniles were exposed to two regimes: C - fed every day for 120 days and 4F/4D - fed for 4 days then deprived for the next 4 days during 45 days (cyclic feeding) and after that, continuous feeding during 75 days. Body mass in 4F/4D juveniles significantly decreased at the end of cyclic feeding but at the end of continuous feeding period, all juveniles showed catch up growth compared to control for both diets. During the continuous feeding period, specific growth rate of 4F/4D juveniles increased significantly showing a compensatory growth response. An increase in food conversion efficiency was also verified in 4F/4D during continuous feeding period being the survival greater than 90% for both diets. Nutritional health was verified through the study of the structure, mass and index of the hepatopancreas showing that cyclic feeding does not cause alterations.Cyclic feeding periods could be applied under culture conditions in C. quadricarinatus juveniles improving yields.