Survival and growth performance the catfish Clarias gariepinus in high density nurseries using recirculating aquaculture system (RAS)

Abstract

The recirculating aquaculture system (RAS) is a cultivation system that minimizes water changes and can optimize high stocking densities (SD). The purpose of this study was to determine the effect of nursery culture in high stocking density with RAS on survival rate (SR), specific growth rate (SGR), relative length (LR), weight gain (WG), length gain (LG)and feed utility efficiency (FUE) of juvenile catfish. The study used a completely randomized design with 4 treatments and 3 replications: R3000 (SD of 3,000 fish/m2 with RAS); NR3000 (SD of 3,000 fish/m2 without RAS); R4000 (SD of 4,000 fish/m2 with RAS); NR4000 (SD of 4,000 fish/m2 without RAS). Juvenile catfish measuring 3.3±0.2 cm were reared for 21 days and water changes were carried out every 2 weeks in the RAS and every 2 days in the non-RAS. The results showed that the SR was not significantly different for all treatments. The highest SGR, LR, WG, LG and FUE were shown in the R4000 treatment (p<0.05). Water quality parameters, especially total ammonia nitrogen in the RAS treatment had a lower value than without RAS. The abundance of total bacteria in the RAS treatment was more than without RAS. This study showed that the density of 4,000 fish/m2 with the RAS was able to provide better catfish nursery production performance than without RAS.