Browsing by Author "Potestas, I. O."
Conference paperP Kungvankij, AG Tacon, K Corre, BP Pudadera, G Taleon, E Borlongan & IO Potestas - 1986 - Asian Fisheries SocietyThis paper presents research attempts to develop a suitable artificial diet for shrimp larvae with locally-available materials. Larval rearing experiments using finely ground Acetes tissues conducted under various climatic conditions and hatchery systems were completed. In the dry season, larvae in outdoor tanks fed dry Acetes had the highest survival rate (68%) compared to larvae fed Chaetoceros (48%) or fresh Acetes (39%). In contrast, larvae from an indoor hatchery reared with Chaetoceros had higher survival rate (52%) than those fed with Acetes (35%) and fresh Acetes (24%). During rainy months, the survival of larvae reared with Skeletonema , dry and fresh Acetes in outdoor tanks was 72%, 52% and 38% and in indoor tanks 62%, 40% and 23%, respectively.
Conference paperBroodfish of grouper (Epinephelus salmoides ) were induced to spawn by hormonal induction. The hormones used for this experiment were HCG + pituitary gland (PG) and LRH-a. The results showed that at dosages of 500 IU HCG + 3 mg of PG per kg of fish for first injection and 1,000 IU HCG + 3 mg of PG per kg of fish at the final injection at an interval of 24 hours, the treated fish spawned naturally in a spawning tank 12 hours after the final injection. At lower dosages of 500 IU HCG + 3 mg PG at 12-hour intervals or 500 IU HCG + 3 mg PG at 24-hour intervals or using 10 mg LRH-a at 12-hour intervals, the eggs can be artificially fertilized only by stripping. The larval rearing experiment was conducted in a 250-l fiberglass tank at the stocking density of 2,500 larvae per tank. Feeds used in this experiment were: (a) Isochrysis + sea urchin eggs; (b) Isochrysis + Brachionus ; and (c) Tetraselmis + Brachionus . The results showed that newly hatched larvae fed with Isochrysis mixed with sea urchin eggs and then Brachionus from day 10 had the best survival rate (9% at day 30).