Culture of Pinfish at Different Stocking Densities and Salinities in Recirculating Aquaculture Systems

Abstract

There is great demand for marine baitfish in U.S. coastal states. The supply of marine baitfish in the United States is almost completely wild caught, and this fishery is seasonal and inconsistent. Aquaculture may be able to consistently supply marine baitfish for anglers. Two experiments were conducted to evaluate the effects of stocking density and salinity on the growth and survival of pinfish Lagodon rhomboides cultured in recirculating aquaculture systems. For the stocking density experiment, juvenile pinfish were stocked (50, 200, 400, and 600 fish/m³) into 1,600-L circular tanks in three identical recirculating systems with a salinity of 27 g/L and were cultured for 82 d. Mean survival was not statistically different among densities and ranged from 94.3% to 99.18%. Daily growth of pinfish ranged from 0.35 to 0.39 g·fish⁻¹·d⁻¹. Mean percent weight gain ranged from 624% to 690% and followed a density-dependent trend. Final total length followed a density-dependent pattern, with each increasing density exhibiting statistically significant decreases in length. Mean feed conversion ratio (FCR) ranged from 1.70 to 1.89. In the salinity experiment, juvenile pinfish were stocked at a density of 120 fish/m³ into 1,600-L tanks within four identical recirculating systems and were cultured for 65 d. Treatment salinities were 9 or 27 g/L; each salinity level was maintained in two systems. Two size-classes were stocked separately into two tanks within all four systems, resulting in four replicates per treatment. Mean survival was not significantly different among treatments and ranged from 98.2% to 99.9%. Mean percent weight gain ranged from 234% to 284%, with no significant differences between salinities. Mean FCR ranged from 2.5 to 3.1 and did not significantly differ between salinities, although fish in the small size-class converted feed more efficiently than those in the large size-class. Pinfish show great potential as a new aquaculture species and can be successfully cultured in recirculating systems at stocking densities of 600 fish/m³ and at a salinity as low as 9g/L.