Abstract

This study was conducted to determine the effect of different dosages of cat fish pituitary gland extract (PGE) on induced spawning of cat fish Clarias gapienus. Four dosages were used (1mg/kg, 2mg/ kg, 3mg /kg and 4mg/kg of females). Each dosages from males (500g to 510g) was injected to females (512g to 520g) at three replications with total of 12 females were injected. Stripping of females happened after (15-17 hours) when the temperature (28 ᵒC - 30 ᵒC). Eggs were weighted and counted. Eggs were fertilized with milt of females then the eggs were incubated in 12 jars (size 3 liter per/one) after (35hr- 39hrs) the hatching of incubation were happened as temperature (28 ᵒC - 30 ᵒC. All hatching and survival rate were counted and recorded. Results indicated that there were significant different (p≤0.05) between the dosages on induced spawning of fish. Eggs weight, eggs number, fertilization rate and hatchability rate were significant (p≤0.05) higher in dosage four (T4) (4mg/kg) as compare with other treatments. Total hatchability rate produced from stripped females were significant (p≤0.05) high in treatment four (T4) (4 mg/kg) as compare with other treatments. Finally the conclusion of this study indicated that high eggs weight, eggs number and hatchability rate were recorded with 4mg/kg body weight of females. Study recommended that the better for induced spawning of catfish were 4mg/kg of females.

Keywords: Catfish; Pituitary gland extract; Dosage; Eggs number; Eggs weight; Fertilization; Hatchability