Effects of stocking density on growth and survival of young Gulf killifish in recirculating aquaculture systems

ABSTRACT

Gulf killifish, Fundulus grandis, is a hardy marine baitfish with established rearing techniques in ponds and static pools, but there is little information about the use of recirculating aquaculture systems (RAS) for growing killifish.The current trial investigated the effects of stocking density on growth and survival of young killifish in RAS. Young fish (28-day posthatch) of 51.6 ± 0.9 mg (mean ± SE) were stocked at 2, 5, 8, and 11 fish/L in 31 L tanks in RAS with triplicate groups for 16 weeks. Cannibalism was a major problem in the study, which increased with increasing initial stocking density, affecting survival negatively. Survival decreased (P < 0.03) with increasing initial stocking density and culture period. At the end of the trial, the 2, 5, 8 and 11 fish/L initial stocking density reduced to 1.66, 1.42, 0.86, and 0.74 fish/L respectively. A significant linear relationship existed between the initial stocking density and weight (y = 0.077x + 2.3; R² = 0.8; P = 0.003), whereas an inverse relationship occurred between initial stocking density and survival parameters (y = −9.43x + 97.4; R² = 0.89; P < 0.001). From the trial, the optimum density for culturing young of Gulf killifish in RAS appears to be around two fish/L.

KEYWORDS:

• Baitfish
• cannibalism
• optimum density
• pond studies
• recirculating technology
• techniques

Acknowledgments

We thank Dr. Christopher Green for his advice and support in the design and development of the study. The authors wish to extend sincere gratitude to Mike Coulon, Josh Patterson, Calvin Fisher, and Paige O’Malley for their help in laboratory work.

Additional information

Funding

This work was supported by the Southern Regional Aquaculture Center, USA.