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

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