dc.description.abstract | Clarias macrocephalus is endemaic yet dwinding freshwater foodfish in the Philippines. Induced breeding protocol was developed after a series of studies which determined the appropriate egg size, proper time of stripping females, effective dose combination of luteinizing hormone-releasing hormone analogue (LHRHa) and pimozide (PIM), and their effects on egg quality. Based on its similar osmotic pressure with catfish plasma, eggs were fixed in 1% phosphate-bufferedd formalin. Catfish eggs with a mean diameter of 1.40 - 1.60 mm were responsive to hormonal treatment and increased to 1.50 - 1.70 mm at ovulation. Oocyte maturation, indicated by eggs in the germinal vesicle breadown (GVBD) stage, was observed at least 13 h pst-injection, followed by ovulation 4 h thereafter. Techniques developed in these studies showed a simsle, convenient, and effective way to induce spawning of C. macrocephalus. A simultaneous injetion of 0.05 ųg LHRHa + 1 ųg PIM/g BW at 1800 - 1900 h, followed by stripping at 16 - 20 h post-injection has consistently resulted in 100% ovulation, high fertilization and hatching rates. | en |
dc.relation.ispartof | In: Chou, L.M., Munro, A.D., Lam, T.J., Chen, T.W., Cheong, L.K.K., Ding, J.K., Hooi, K.K., Khoo, H.W., Phang, V.P.E., Shim, K.F., Tan, C.H. (eds.). The Third Asian Fisheries Forum. Proceedings of the Third Asian Fisheries Forum, 26-30 October 1992, Singapore. Manila, Philippines: Asian Fisheries Society. pp. 830-833 | en |