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

The Caribbean flounder Paralichthys tropicus is a relatively economic seafo od specie in Venezuela, mainly as a high-price restaurant dish. Preliminary studies have been conducted at the School of Applied Marine Sciences (Univ ersity of Oriente) to evaluate the potentiality of the species. In northeas tern Venezuela the species is distributed around the Islands of Margarita a nd Cubagua, where it has two distinct spawning seasons, from December to Ma rch and from July to August. This study reports the results of preliminary research conducted on some reproductive aspects of the Caribbean flounder a nd its induced spawning under laboratory conditions, stomach content analys is, 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 is lands. Average female weight was 430.6 (s.d. 414.5) g, and average male wei ght was 305.1 (s.d. 218.7) g. During February 1997 six additional individua ls were captured in the same area and transported live to the laboratory fo r spawning induction. Three females with an average weight of 931.1 (s.d. 5 15.9) 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) mu m. After hormonal injection animals were placed in 2 m(3) rearing tank w ith continuous water exchange and aeration, with 39 ppt. salinity and tempe rature of 24.1 degrees C. The first observed spawning occurred 11 h after h ormonal treatment, and a second one was detected 24 h later. Fertilized egg s had an average size of 684.6 (s.d. 27.20) mu m. The embryonic development lasted until the blastula stage was reached and then it stopped. No egg ha tching was detected. Adult fish are still being maintained in the tank, hav e adapted well to rearing conditions, and appear to have an acceptable grow th rate for aquaculture specie. (C) 1999 Elsevier Science B.V. All rights r eserved.