MATERIALS AND METHODS
Experimental Fish and Hormone Injection
The experiment was conducted at Fangam integrated
Fish farm at Mariri in Kumbotso Local Government
area, Kano State. Matured Males and Females of C.
gariepinus sizes range from (700-1500)g were
procured for the experiment from fangam integrated
farm and stock in concrete tanks size of 2m2
at the
hatchery complex. 15Males and Females fish were
selected eachand group into two according to sizes
and the females brooder were injected with Human
Gonadotropin hormone (trade mark: Ovaprim) at
dosage of 0.5ml per kilogram (kg) of fish body weight
and the injection was done intramuscularly under the
pectoral fin or at the neck. The injected area was
rubbed with a finger in order to distribute the Ovaprim
hormone evenly throughout the muscle and to prevent
backflow of the Ovaprim hormone. The injected fish
were kept in well aerated water in a small tank. The
temperature of the water holding the fish was
measured with mercury in glass thermometer and the
corresponding latency times were taken and the milt
used was collected by sacrificing the males. The male
was dissected using a sharp razor blade and the testes
were removed, cleaned off the blood with a tissuepaper
and kept in a plastic bowl with a saline solution
until needed. Incision was made into the creamy
coloured lobes of the testes and the milt was
squeezed out of the testes sac with physiological
solution. The injection took place between 8.00pm
and 9.00pm.