Browsing by Author "Chua, Thia-Eng"
Effects of food ration on growth, condition factor, food conversion efficiency, and net yield of estuary grouper, Epinephelus salmoides Maxwell, cultured in floating net-cages The effects of food ration on the growth and yield of the estuary grouper raised in floating net-cages were investigated. The optimum ration given on alternate days was 5% body weight (wet) which gave the best mean fish weight, uniform condition factor with time, relatively good survival rate, and greatest efficiency of food conversion. The maintenance, optimum and maximum food rations were 1.41, 5.75, and 9.0% body weight (wet) respectively. The fish were more uniform in size when fed 5-8% body weight. Though the yields at the end of the experiment were higher with high ration rates, the difference between rations of 5 and 9.1% body weight was 26.8 and 33.6%, whilst that between 5% and 2% body weight was 596%. For economic production, the ration should be approximately 5% of body weight supplied every 2 days.
Conference paperTU Bagarinao & TE Chua - In JL Maclean, LB Dizon & LV Hosillos (Eds.), The First Asian Fisheries Forum. Proceedings of the First Asian Fisheries Forum, 26-31 May 1986, Manila, Philippines, 1986 - Asian Fisheries SocietyA survey of the early life history characteristics of 135 teleost fishes from freshwater, marine, tropical, temperate and boreal habitats show the influence of egg size and larval size on survival potential. Marine species have smaller eggs and larvae than freshwater species at similar temperatures. Coldwater species tend to have larger eggs and larvae than warm water species. Egg diameters are positively correlated with larval lengths (Lh) and weights at hatching. The times from fertilization to onset of feeding (tf), to yolk and oil resorption (ty) and to irreversible starvation (ts), increase linearly with Lh and decrease exponentially with temperature. Both tf and ts are positive linear functions of ty. Thus, larger larvae with much yolk that lasts for a relatively longer period feed later and if not fed, will starve later than small larvae with little yolk. Larger larvae will thus have the advantage under conditions of limited or variable food supply. Moreover, large larvae tend to have large mouths and are thus capable of ingesting large high-calorie prey. They also tend to have higher swimming speeds and greater potential to encounter food and avoid predators. There is no definite relation between growth rates and Lh, but tropical species with small eggs and larvae tend to have high growth rates. Survival potential has implications in the recruitment to natural stocks and in seed production in hatcheries.
BookP Kungvankij, LB Tiro Jr., BJ Pudadera Jr., IO Potestas, KG Corre, EL Borlongan, GA Talean, LF Bustilo, ET Tech, A Unggui & TE Chua - 1986 - Network of Aquaculture Centres in Asia
Series: Aquaculture extension manual; No. 14Details are given of factors to be taken into account for successful hatchery operation. The following aspects are covered: 1) site selection; 2) hatchery design and construction; 3) life cycle; 4) preparation of broodstock for spawning; 5) larval feed; 6) spawning, hatching and larval rearing facilities; 7) spawner selection and egg collection 8) nauplii hatching and transportation; 9) larval rearing; 10) routine hatching, management; 11) port-larvae nursery; and 12) larval harvesting and transportation.