Effect of stocking density on the reproductive performance of Nile tilapia (Oreochromis niloticus, Linnaeus) spawned in net hapas | |
| Author | Abrajano-Bongco, Aurea |
| Call Number | AIT Thesis no. AE-91-32 |
| Subject(s) | Tilapia Fishes--Spawning, Induced |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science |
| Publisher | Asian Institute of Technology |
| Abstract | Oreochromis niloticus female broodstock, with an average size of 94 grams were spawned with the males that were conditioned or not conditioned prior to stocking in spawning net hapas. Increasing total stocking densities of 0.6. 1.25, 2.5, 5 and 10 fish/m2 were tried at 1:1 sex ratio. The reproductive performance and fish growth were evaluated during a 76-day culture breeding period. Significant differences and recognizable trends in terms of seed quantity and quality among treatments were measured. Increasing stocking densities caused significant increases in seed yield per unit area. The highest reproductive output was registered at 5 fish/m2, beyond that, seed production declined. Optimal densities of broodfish produced seed output of more than 120 seed/m2 in each spawning hapa consistently during the breeding experiment. Results indicate that the percentage of females spawning increases with decreasing stocking density. Also, at lower densities, harvested seed was more of a advanced egg stage (Stage 3: yolk sac larvae) indicating that spawning took place shortly after stocking. Conversely, delayed spawning was suspected at higher densities. Better broods tock performance was noted with females spawned with unconditioned males than with conditioned males. |
| Year | 1991 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Little, David C.; |
| Examination Committee(s) | Yakupitiyage, Amararatne;Knud-Hansen, Christopher F.; |
| Scholarship Donor(s) | Government of the Netherlands; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1991 |