Optimizing Stocking Density and Feeding Practices for Improved Growth and Survival of Asian Seabass (Lates calcarifer) in Marine Cages at Mandapam Coastal Waters
S. Boobalan
Fisheries College and Research Institute, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Thoothukudi, 628 008, Tamil Nadu, India.
C. Anand *
Mandapam Centre for Sustainable Aquaculture, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Mandapam, Ramanathapuram, 623 519, Tamil Nadu, India.
C. Judith Betsy
Institute of Fisheries Postgraduate Studies, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Chennai, 603 103. Tamil Nadu, India.
S. Prakash
Mandapam Centre for Sustainable Aquaculture, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Mandapam, Ramanathapuram, 623 519, Tamil Nadu, India.
Shrinath Vaijanath Gavhane
Mandapam Centre for Sustainable Aquaculture, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Mandapam, Ramanathapuram, 623 519, Tamil Nadu, India and Dr. M.G.R Fisheries College and Research Institute, Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Ponneri-601 204, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
Abstract
Aim: Asian seabass, Lates calcarifer, is a promising species for marine cage aquaculture because of its fast growth rate, high feed conversion efficiency and euryhaline nature. This study aimed to determine the optimal stocking density and evaluate the influence of different feeding regimes on the growth performance and survival of L. calcarifer in marine cages.
Study Design: The research was conducted in two experiments. The first experiment tested three stocking densities, while the second experiment compared two feeding regimes at the optimal density identified from the first experiment.
Place and Duration of Study: Mandapam Centre for Sustainable Aquaculture, Mandapam, Ramanathapuram District, Tamil Nadu, India. Both experiments were carried out over 60 days.
Methodology: In Experiment 1, L. calcarifer juveniles were stocked at 10, 15 and 20 fish/m³. Based on the results, Experiment 2 was conducted at 10 fish/m³ to compare trash fish with sinking pellet feed. Growth parameters, survival, feed conversion ratio (FCR) and feed efficiency were measured.
Results: In Experiment 1, fish stocked at 10 fish/m³ exhibited significantly higher weight gain (139.1 ± 6.3 g), specific growth rate (3.3 ± 0.00%/day) and survival (57.0 ± 0.9%) than those stocked at 15 and 20 fish/m³ (P < 0.05). In Experiment 2, fish fed sinking pellets achieved significantly higher final body weight (244.1 ± 3.6 g), weight gain (202.0 ± 4.9 g) and length gain (10.7 ± 0.4 cm) than fish fed trash fish (P < 0.05). However, survival, feed conversion ratio and feed conversion efficiency did not differ significantly between feeding treatments (P > 0.05).
Conclusion: The optimal stocking density for L. calcarifer in marine cages was 10 fish/m³. Sinking pellet feed was effective and feasible for commercial farming, supporting improved growth and feed efficiency.
Keywords: Asian seabass, Lates calcarifer, marine cage culture, stocking density, feeding regime, sinking pellet feed, trash fish, growth performance, survival, feed conversion ratio.