The potential use of the Caribbean flounder Paralichthys tropicus as an aquaculture species

Abstract

The Caribbean flounder Paralichthys tropicus is a relatively economic seafood specie in Venezuela, mainly as a high-price restaurant dish. Preliminary studies have been conducted at the School of Applied Marine Sciences (University of Oriente) to evaluate the potentiality of the species. In northeastern Venezuela the species is distributed around the Islands of Margarita and Cubagua, where it has two distinct spawning seasons, from December to March and from July to August. This study reports the results of preliminary research conducted on some reproductive aspects of the Caribbean flounder and its induced spawning under laboratory conditions, stomach content analysis, and chemical proximal analyses of flesh and gonads. During January 1997 a total of 37 individuals (27 females:10 males) were captured alive using fishing nets deployed at various locations around Cubagua and Margarita islands. Average female weight was 430.6 (s.d. 414.5) g, and average male weight was 305.1 (s.d. 218.7) g. During February 1997 six additional individuals were captured in the same area and transported live to the laboratory for spawning induction. Three females with an average weight of 931.1 (s.d. 515.9) g and three males with an average weight of 576.5 (s.d. 121.1) g were injected with commercial grade Human Chorionic Gonadotropin (HCG) at 2 UI/g (females) and 1 IU/g (males). Average ovocite size was 614.6 (s.d. 24.6) μm. After hormonal injection animals were placed in 2 m 3 rearing tank with continuous water exchange and aeration, with 39 ppt. salinity and temperature of 24.1°C. The first observed spawning occurred 11 h after hormonal treatment, and a second one was detected 24 h later. Fertilized eggs had an average size of 684.6 (s.d. 27.20) μm. The embryonic development lasted until the blastula stage was reached and then it stopped. No egg hatching was detected. Adult fish are still being maintained in the tank, have adapted well to rearing conditions, and appear to have an acceptable growth rate for aquaculture specie.