LHRHa and pimozide-induced breeding in the catfish, Clarias macrocephalus (Gunther).
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.
Fermin, Armando C.; Bolivar, Maria Edna C.; Balad-on, S. B. M.; Vargas, J. B. (European Aquaculture Society, 1995)The Asian catfish, Clarias macrocephalus, is a popular freshwater foodfish in the Philippines. However, grow-out farming of this species is hampered by the lack of juveniles for stocking. A series of experiments on zooplankton ...
Coniza, Eliseo B.; Catacutan, Mae R.; Tan-Fermin, Josefa D. (Aquaculture Department, Southeast Asian Fisheries Development Center, 2008)Asian catfish Clarias macrocephalus is an esteemed food fish especially in Southeast Asia due to its tender and delicious meat. This commodity constitutes a valuable fishery for small-scale fishers in the region and has a ...