Abstract

D. D. O Okoro, Atunisha Umukoro Micheal and S. P. George

Ripe Clarias anguillaris, with a size ranging from 350 to 600 g total body weight (TBW) (mean weight of 434.44 ± 79.39 g), were treated with frog (Xenopus laevis) crude pituitary glands at three treatment levels of 1 pituitary, 2 pituitaries and 3 pituitaries per broodstock and the control treated with Ovaprim. Each treatment was replicated three times. The frogs’ weight ranged from 29.40 to 105.59 g. The latency period before successful stripping was observed to range from 9 to 14 h according to the hormone dosage. Eggs were incubated at a temperature range of 26 to 27°C. Hatching started after 24 h and was completed by 36 h of incubation. Egg yield or fecundity was observed to vary according to the dosage of pituitary glands administered. Two pituitary glands injection yielded the highest egg number with mean fecundity of 47081 ± 10516 followed by one pituitary gland treatment with mean fecundity of 34785 ± 7537. Three pituitary glands treatment gave the least fecundity of 26007 ± 4359. Percentage fertilization and hatching of the eggs were also higher in two pituitary glands treatment with 98% fertilization and hatching. This was followed by one pituitary (75%) and three pituitary glands with 62% fertilization and hatching. The fries were reared for 8 weeks. Mortality was observed to be highest during the second week in all the three treatments. Treatment two (2 pituitaries) still had the highest survival of 68.40% followed by treatment one (1 pituitary) with 29.60% survival and treatment three (3 pituitaries) with only 4.80% survival. The stock stabilized and no mortality (0%) was recorded from 3rd to 8th weeks of rearing. Results indicated that 2 pituitary glands treatment was most effective followed by 1 and 3 glands treatments respectively. Weight of frogs and their respective pituitaries and weight of fish appeared to have relative effects on their productivity. Three frogs (T3) of mean weight 67.52 ± 33.70 were observed to be an over dose to a fish of 434.44 g mean weight.