INFLUENCE OF PREY (ARTEMIA NAUPLII) DENSITIES ON THE SURVIVAL, GROWTH AND FEED CONSUMPTION OF SPOTTED SCAT SCATOPHAGUS ARGUS LARVAE, AN INDO-PACIFIC ORNAMENTAL FISH REARED UNDER CONTROLLED CONDITION

Abstract

Spotted Scat (Scatophagus argus) is a popular brackish water Ornamental fish but currently sourced largely from the wild. To optimize the conditions on the food ration to be supplied and rearing with live feed, an experiment was conducted to evaluate the survival and growth with different rations of Artemia nauplii under laboratory conditions. 10-day post-hatch (DPH) hatchery produced larvae of Scat with a mean length of 4.07±0.00 mm were stocked @ 10 fish L-1 in 50 L fiber tanks filled with 30-L of filtered sea water and fed with five different prey densities of 4, 8, 12, 16 and 20 nauplii ml-1 day-1. An experiment was conducted for 15 days and was performed with six replicates. Survival of S.argus larvae improved linearly (80% to 100%) with feeding density. The higher feeding level of 20 nauplii ml-1day-1 showed a significant (p less than 0.05) increase in growth (13.6±0.08 mm/138.3±2.70 mg) of S. argus larvae, compared to the lower densities of 4, 8, 12 and 16 nauplii ml-1day-1. The foraging and their feeding behavior of larvae were observed regularly and the performance indices were documented. The present findings are a first step towards the development of a production protocol for S. argus in the laboratory. Our results demonstrated the importance of live feed Artemia nauplii as prey for rearing S. argus larvae and suggests a reliable consumption pattern with reference to the feed availability and its effect on their growth.