Stocking Density Effects on Production Characteristics and Body Composition of Market Size Cobia, Rachycentron canadum, Reared in Recirculating Aquaculture Systems

Authors

  • Marty A. Riche,

    Corresponding author
    • United States Department of Agriculture, Agricultural Research Service, Fort Pierce, Florida, USA
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    • Present address: USDA, Agricultural Research Service, Stuttgart National Aquaculture, Research Center, 2955 Hwy 130 East, Stuttgart, Arkansas 72160, USA.

  • Charles R. Weirich,

    1. United States Department of Agriculture, Agricultural Research Service, Fort Pierce, Florida, USA
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    • Present address: Aqua Green, LLC, 60 Chalet Drive, Perkinston, Mississippi 39573, USA.

  • Paul S. Wills,

    1. Center for Aquaculture and Stock Enhancement, Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
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  • Richard M. Baptiste

    1. Center for Aquaculture and Stock Enhancement, Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
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Corresponding author.

Abstract

Culture density in excess of a critical threshold can result in a negative relationship between stocking density and fish production. This study was conducted to evaluate production characteristics of juvenile cobia, Rachycentron canadum, reared to market size in production-scale recirculating aquaculture systems (RAS) at three different densities. Cobia (322 ± 69 g initial weight) were reared for 119 d at densities to attain a final in-tank biomass of 10, 20, or 30 kg/m3. The specific objective was to determine the effects of in-tank crowding resulting from higher biomass per unit rearing volume independent of system loading rates. Survival was ≥96% among all treatments. Mean final weight ranged from 2.13 to 2.15 kg with feed conversion efficiencies of 65–66%. No significant differences were detected in growth rate, survival, feed efficiency, or body composition. This study demonstrates that cobia can be reared to >2 kg final weight at densities ≤30 kg/m3 under suitable environmental conditions without detrimental effects on production.

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