Browsing by Author "Borlongan, Emeterio"
Effect of substrate types on fecundity and nauplii production of ablated Penaeus monodon Fabricius. RA Pudadera, JH Primavera & E Borlongan -
The Philippine Journal of Science, 1980 - Science and Technology Information Institute, Department of Science and TechnologyThe survival, spawning, fecundity, and nauplii production of ablated Penaeus monodon females reared in flow-through broodstock tanks with white coralline and black sand substrates for 62 days, were assessed. Prawns exposed to the white coralline substrate consistently produced eggs with significantly higher (P - 0.05) average hatching rates and total nauplii production than those exposed to the black sand substrate. No differences were observed in the fecundity, spawning and survival rates in both treatments. It was observed that nightly sampling of ablated females during experiment 2 produced a higher number of spawning (48) and total number of nauplii produced (6.8 milion) compared to twice weekly sampling in experiment I (29 spawnings and 3.0 million nauplii) for the white substrate.
ArticleJH Primavera & E Borlongan -
SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development CenterTo what extent spent P. monodon females can remature and spawn successive broods is an important question in terms of recycling spawners in a commercially viable operation. Corollary to this is the quantity and quality of fry from rematured females in comparison to those from first spawning. Of 347 experimental females, only 10.1% had a second spawning, and 1.4% a third spawning. To a large degree the low rate of rematuration is due to high spawner mortality - average survival period after spawning was only 6 days in a sample of 176 spawners. It took an average of 23 days after ablation for a prawn with undeveloped ovaries to mature and spawn. An ablated female may have another spawning in as little as 5 days after the previous one. Average fecundity was 180,000 eggs per second spawning, and 140,000 eggs per third spawning. The average number of eggs from first spawning ablated females was 110-120,000. Hatching rate was lower for rematuration: 44% for second spawnings, and 35% for third spawnings, as compared to 64% for first maturation.
BookP Kungvankij, LB Tiro Jr., BJ Pudadera Jr., E Borlongan, ET Tech & TE Chua - 1989 - Aquaculture Department, Southeast Asian Fisheries Development Center
Series: NACA technology series; No. 4A description is given of the prototype warm water shrimp hatchery established and operated by SEAFDEC Aquaculture Department since 1982. Hatchery design, operation and management, larval rearing in small indoor tanks, larval rearing in large nursery tanks, routine hatchery management, harvesting and transportation and financial aspects are covered.
ArticleJH Primavera, E Borlongan & RA Posadas -
SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development CenterP. monodon spawners, transported from maturation pens suffer from stress which in turn may lead to lowered spawning rate or fertility. Spawning the females in the maturation site and transporting the eggs to the hatchery site is being considered as an alternative. Egg transport costs may be reduced to a minimum by using eggs from ablated spawners, transported at high density with no aeration. Experiments on higher egg densities as well as on transport of nauplii should, however, be undertaken.