EFFECT OF A SYNTHETIC LHRH ANALOG AND DOPAMINE ANTAGONISTS ON THE MATURATION OF BREAM, ABRAMIS-BRAMA L

Induced ovulation and spawning of bream (Abramis brama L.) were studied using the synthetic LHRH analogue (des Gly10[D-Ala6]-LHRH) at a total dose of 5-mu-g/kg and 4-mu-g/kg for females and males, respectively, and the dopamine antagonists eglonil and metoclopramide at a total dose of 5 mg/kg and 4 mg/kg for females and males, respectively (38 individuals weighing 0.55 kg to 1.3 kg). Males were given single intramuscular injections. Females received double injections, with 20% injected as a priming and 80% as a resolving dose administered 13.5 h later. With all applications we observed 100% spermiation 20-30 h after injection. In females, the most effective method was the use of des Gly10[D-Ala6]-LHRH plus metoclopramide. In this group 75% of the females ovulated. In the des Gly10[D-Ala6]-LHRH plus eglonil group 33% of the females ovulated. In the des Gly10[D-Ala6]-LHRH group no ovulation was observed. The results obtained may be used as a basis for developing full-cycle bream cultivation.