Effect of feeding frequency on growth and survival of juvenile crayfish Cherax quadricarinatus (von Martens, 1868) (Decapoda: Parastacidae)

Abstract

The effect of feeding frequency on the growth and survival of juvenile freshwater crayfish Cherax quadricarinatus with initial mean weight of 0.89 ± 0.06 g was evaluated in a 60-day study. Juveniles were fed with four different feeding frequencies: every 24 h (C1), 12 h (C2), 6 h (C3) and 4 h (C4), with a 35% crude protein diet. Specific Growth Rates (SGR) of 3.02 and 2.79%/day showed that feeding frequency treatments C3 and C4 maximize growth of juvenile C. quadricarinatus, reaching final mean weights of 4.7 and 5.4 g, biomasses of 253.2 and 311.8/m2, and Feed Conversion Ratios (FCR's) of 1.8 and 1.2, respectively. Treatments, C1 and C2 showed significantly higher FCRs. Survival ranged from 86.7 to 98.3%, and was statistically different among the experimental treatments, except for organisms fed with C1 and C2. Final weights of juvenile C. quadricarinatus showed that a feeding frequency of at least three times a day (C3) was significantly better. However, in terms of biomass, treatment C4 was better. The information obtained will contribute to improve the understanding of the dynamics of distribution of feeds and to correlate it with the nutritional condition of juvenile C. quadricarinatus.