EFFECTS OF ZEOLITE LEVELS ON GROWTH INDEXES OF JUVENILE FRESHWATER CRAYFISH (ASTACUS LEPTODACTYLUS)

To decrease cost of the commercial formulated food in culture of freshwater crayfish (Astacus leptodactylus), inexpensive additives like Zeolite can be incorporated into food. An eight week experiment was conducted on juvenile freshwater crayfish to determine the suitable level of Zeolite in food of the fish. Four levels of Zeolite 0.5, 1, 1.5 and 2 percent with three replications each and a digestible energy (DE) of 3500Kcal/kg diet were formulated. Five hundred and forty juvenile crayfish weighing 2±0.8 grams each were randomly distributed between twelve aquariums of 250 liter capacity. Juveniles were fed on pellet foods at 8 percent of body weight four times a day. Different nutritional responses in terms of weight gain (WG), Relative growth rate (RGR), food conversion ratio (FCR), protein efficiency ratio (PER) and survival rate (SR) were calculated and compared. WG, RGR and SR in treatments (1, 2, 3, 4) were not significant statistically (P>0.05) as compared to the control group. FCR and PER improved with Zeolite addition and in treatment four with 2 percent Zeolite level showed significant difference (P<0.05). No significant difference was found between treatments 1, 2, 3 and the control diet. Body carcass composition assessment of the crayfish fed on different levels of Zeolite was not significantly different to that of the treatment.