2. Materials and methods
2.1. Broodstock selection and maintenance
Experiments were conducted at the Animal and Fish
Production Department, Suez Canal University, Ismailia,
Egypt. Adult female catfish Clarias gariepinus
(selected by certain external morphologic characteristics)
were captured from fish farms [14]. Ovarian biopsies
were taken, only fish having more than 60% of the
oocytes with a migrating germinal vesicle were selected
for ovulation experiment. Thirty-six female fish weighing
500 to 1000-g body weight (BW) were selected.
Before injection fish were individually weighed and
assigned to nine groups. No food was provided during
the experiment