Effect of substrate on growth, survival and moulting in Juvenile Red Claw, Cherax quadricarinatus

The experiment was conducted to determine the effects of different substrate on the survival, growth and total number of moulting in juvenile red claw, Cherax quadricarinatus for aquaculture purposes. In the present study, there is a problem in culturing juvenile stage of C. quadricarinatus especially for survival and growth. Thus, a substrate was used to improve the survival and growth of C. quadricarinatus especially for the intensive system due C. quadricarinatus need a large space to survive. C quadricarinatus with initial body weight from 1.10 to 2.90 g, total length 2.82 to 4.36 cm were placed in tanks (80 L in volume capacity) with 55L in water and there are eight juveniles in each tank. Treatment tanks were introduced with coral as treatment 2 and pipe as treatment 3. While, tank without shelters was set as control (treatment 1). Black nets were installed on top of each for circumventing foreign objects enter the tank and protect from direct sunlight. Besides, C. quadricarinatus were acclimatized for seven days before started the experiment. The experiment was done in duplicate and conducted for 60 days and C. quadricarinatus were fed twice daily (morning and evening) based on 5% of body weight. From the total of two replications, C. quadricarinatus for treatment 2 (coral) were significantly in survival (81.25±8.84%), weight gain (347.36 ±6.04%), specific growth rate (2.50±0.02%), carapace length (32.93 ± 0.93 %) and total number of moulting (55.00±2.93%) compared to other treatments. Besides, the control treatment (treatment 1) has a lower percentage in survival (37.50±8.84%) weight gain (122.60±20.51%) specific growth rate (1.33±0.15%), carapace length (25.84±0.33 %) and total number of molting (29.00±0.71%). As a conclusion, usage of coral as the substrate in the rearing tank showed improvement in survival, weight gain, specific growth rate, carapace length and total number of molting in C. quadricarinatus. The coral can use in rearing tank for increase the growth and survival for a small scale and not for commercial. In addition, in the environmental aspect, the present study showed the benefit of replacing the use of PVC pipes with the natural structure of dead coral