African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Effects of different stocking densities on tiger grouper juvenile (Epinephelus fuscoguttatus) growth and a comparative study of the flow-through and recirculating aquaculture systems

Reza Salari, Che Roos Saad*, Mohd Salleh Kamarudin and Hadi Zokaeifar
  Department of Aquaculture, Faculty of Agriculture, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia.  
Email: [email protected], [email protected]

  •  Accepted: 01 March 2012
  •  Published: 10 July 2012

Abstract

Two experiments at different water-flow conditions and stock densities in the critical 6-week nursery phase determined growth, survival and feed conversion of brown-marble grouper juveniles at 35 Day After Hatching (DAH) with initial mean body weight of 0.045±0.02 g and total mean length of 15.08±0.4 mm. In the first experiment, juveniles of 35 DAH were kept in an 80 L fiberglass tank with the flow-through system for 42 days of the nursery phase at three densities: 1, 3 and 5 ind/L. The highest specific growth rate (P<0.05) and the lowest food conversion ratio (P<0.05) were observed for fish at the 3 ind/L stocking density compared to the other groups. No statistically significant differences (P>0.05) were found in the survival rate of fish groups held in any stocking density. In the second experiment, juveniles of 35 DAH were reared with a re-circulating aquaculture system (RAS) at three densities, 1, 3 and 5 ind/L, to evaluate the effects density has on grouper growth and survival rate in the RAS system, and results were compared with the open flow-through system. No statistically significant differences (P>0.05) were found in total length and body weight between treatments (1, 3, 5 fish/L) in the RAS system, while the weight and total length of the fish reared in open water flow-through conditions were significantly larger (P<0.05) than fish reared in the RAS. This study suggests that optimum stocking density in a flow-through system is 3 fish per liter and flow-through water is preferred to the RAS system.