Efficacy of Osteolaemus tetraspis Pituitary Gland (APG) Hormone on Induced Spawning of Clarias gariepinus

Abstract

The experiment was conducted to ascertain efficacy of Osteolaemus tetraspis Pituitary Gland (APG) hormone on induced spawning of fish. The research work was carried out between January and May 2008 at the Nigeria Institute of Oceanography and Marine Research (NIOMR) Sapele. Thirty-nine fish samples of Clarias gariepinus (36 females and 3 males) and three alligators were used. The means weight of the fish was 800 ± 20 g while that of the alligator was 5.0 ± 0.2 k g. Three replicate trials were done to observe spawning activities using three different doses, (0.5 ml, 1.0 ml and 2.0 ml) of acetone -dried APG Ovulation was recorded after 11-13 hours post-injection. Eggs were obtained by stripping and fertilized artificially with milt from the male Clarias and incubated in plastic bowls. Hatching occurred within 20-26 hours after fertilization at a water temperature of 25-26 degree centigrade. Fertilization and hatching percentages increased (p < 0.05) with increase in hormone dosage. ANOVA of the means of hatching did not show any significant different in the dosage used. The overall breeding performances of the APG hormone were found to be satisfactorily. Experiment on standardization of the APG hormone is however recommended.