Experimental Culture and Particle Filtration by Asian Moon Scallops, Amusium pleuronectes

Abstract

Growth rates were determined for scallops (35-75 mm valve height) held in pocket nets and lantern nets at varying densities. The Ford-Walford linear transformation of the von Bertalanffy growth equation was used to allow quantification or food-limited stunting. Pocket nets allowed for greater growth of scallops than did the lantern nets at all stocking densities. The growth rates of scallops in pocket nets, nevertheless, were well below the growth of scallops in the wild. Clearance rates of Caribbean strains of Isochrysis galbana (C-lso) and Chaetocerous gracilus (C-Cg) were determined for moon scallops, Amusium pleuronectes, in static chambers at 28 °C. The scal­lops have a great capacity to filter both species of phytoplankton. Clearance rates ranged from 2.84 to 12.13 l·(g·h)·1 dry weight (4.7 x 106 to 9.8 x 106 cells·min•1 or 1.3 x 108 to 2.8 x 108 cells·[g·hI·1) in pre-conditioned 70-mm animals. The threshold cell concentration for the beginning of pseudofeces production is <20,000 C-Cg cells·m1·1• The high rates of particle clearance and con­comitant water transport by A. pleuronectes are adaptations to their native warm oligotrophic waters. These high clearance rates, coupled with their habit of active swimming (>9 m per swim), may limit this species to low density bottom pen culture methods.