Efficacy of human chorionic gonadotropin (hCG) and crude pituitary extract of fish and frog in oocyte maturation and ovulation in African catfish,Clarias gariepinusBurchell, 1822 andClarias anguillarisL., 1762

摘要

Abstract.The African catfish,Clarias gariepinusBurchell andClarias anguillarisL., were induced to ovulate in aquaria by the administration of human chorionic gonadotropin (hCG) and pituitary extracts ofClarias albopunctatus(NicholsLamonte) and frog,Rana elegans.For final maturation and ovulation in both species ofClarias, the total dosage of each hormone was inversely proportional to the initial oocyte diameters of the recipient females. The time of ovulation after the last injection (latent period) was significantly shorter (11–13h) in females with large oocyte diameters (>920μm) than in those whose mean oocyte diameters were less than 920 μm (13–16h) (P0μ05) and was about 86.Clarias albopunclatus and R. elegans, which are economically unimportant and abundant in Anambra River basin, Nigeria, could be used as effective sources of hypophyseal factors inClariasbreeding pr