Commercial Production of Pla Boo (Oxyeleotris marmoratus) Fry

Abstract

Experiments on breeding of Pla Boo (Oxyeleotn's marmoratus) for the commercial purpose were conducted at the Department of Aquaculture, Faculty of Fisheries, Kasetsart University during December 1981 - September 1983 by comparing the breeding methods between induced spawning by hormone injections and natural controlled reproduction. Growth and survival of fish fry fed continuously hard boiled egg yolk, rotifers, and water fleas were also measured and estimated. Breeding of Pla Boo under the natural controlled reproduction method gave 80.44% hatchubility whereas induced spawning by hormone injection gave 67.08% hatchability. Thirty thousands of yolk-stage larvae from 2 breeding methods and 5,000 larvae from each of 3 replications were used to observe growth and survival for a period of 60 days. Three days after the yolk-sac was completely absorbed, it was found that 3,831 (76.62%) fish of 0.33 - 0.37 cm long survived. After feeding with hard boiled egg yolk for 5 day, the fish grew up to 0.39 - 0.45 cm and 2,159 (43.18%) fish survived; after feeding with microplankton (green water) for 23 days, the fish grew up to 0.71 - 0.97 cm and 1,048 (20.96%) fish survived; after feeding with young water fleas for 23 days, the fish grew up to 1.37- 1.61 cm and 753 (15.06 %) fish survived; and after feeding with various sizes of water fleas for 15 days, the fish grew up to 1.50 - 1.78 cm and 691 (13.82%) fish survived. As for fish obtained from natural controlled reproduction, it was found that 4,251 (85.02%) fish of 0.33 - 0.37 cm long survived. After feeding with hard boiled egg yolk for 5 days, the fish grew up to 0.39 - 0.45 cm and 2,577 (51.54%) fish survived; after feeding with microplankton (green water) for 23 days, the fish grew up to 0.83 - 1.00 cm and 1,483 (29.66%) fish survived; after feeding with young water fleas for 15 days, the fish grew up to 1.43 - 1.67 cm and 1,171 (23.42%) fish survived; and after feeding with various sizes of water fleas for 15 days, the fish grew up to 1.50 - 1.89 cm and 1,037 (20.74%) fish survived. The above results revealed that the natural controlled reproduction was the better breeding method. Feeding fish larvae with the combinations of hard boiled egg yolk and living food organisms with the amount according to the respective sizes of fish assured the high survival rate up to commercial quantity.