Induction of ovulation in female mud skipper (Boleophthalmus pectinirest ris) by HCG,analogue of LHRH and pimozide

The effects of two intraperitoneal injections of human chorionic gonadotropin (HCG) or D-ALA⁶, pro⁹-N-ethylamide]-luteinizing hormone releasing hormone analogue (LHRH-A), respectively, and the combined effect of LHRH-A with pimozide (PIM), a dopamine antagonist, on ovulation in female mud skipper were investigated. A high rate of ovulation (83.3%) was observed after injection with HCG(30 I. U./g). Injection of LHRH-A at a total dosage of 2 μg/g was 100% effective in inducing ovulation. No ovulations occurred in the group receiving a low dosage of LHRH-A (0.02 μg/g). Injection of LHRH-A (0.2 μg/g) with PIM (10 or 20 μg/g) induced greater ovulatory response than injection with LHRH-A (0.2 μg/g) alone. PIM at total dosages of 0.2 μg/g or 2 μg/g did not enhance the potency of LHRH-A to stimulate ovulation.