The Effects of Using Different Levels of Calcium Carbonate (CaCO3) on Growth, Survival, Molting Frequency and Body Composition of Freshwater Crayfish Juvenile, Pontastacus leptodactylus (Eschscholtz, 1823)

Abstract

The present study was conducted to determine different calcium carbonate (CaCO3) level effects on growth, survival, molting frequency and body composition of freshwater crayfish juvenile, Pontastacus leptodactylus (Eschscholtz, 1823). Initial mean weight and length juvenile crayfish were measured to be 0.53 +/- 0.01 g and 22.0 +/- 0.05 mm, respectively. Crayfish were stocked randomly in twelve aquariums in area of 0.2 m(2) at the rate of 50 crayfish/m(2). The different level of CaCO3 was added into a commercial trout diet (Control), 3%, 6% and 12% for feeding the juvenile crayfish. After 90-day study, supplementation of CaCO3 significantly (P<0.05) did affect growth rate, specific growth rate, feed intake, molting frequency, biomass, but reduced survival of crayfish at level of 6% diet as compared to the other groups. The proximate composition of tail meat of crayfish was unaffected by the diet. These results indicated that the calcium carbonate addition is required for crayfish. At the end of the experiment, 6% of calcium carbonate was suggested to be used in formulated diets for crayfish juvenile.