Controlled reproduction of asp, Aspius aspius (L.) using luteinizing hormone releasing hormone (LHRH) analogues with dopamine inhibitors

Artificial reproduction of asp under controlled conditions was investigated using two different spawning agents based on luteinizing hormone releasing hormone (LHRH) analogues and dopamine antagonists (Ovopel and Ovaprim), during two successive spawning seasons. Fish in the Ovopel and Ovaprim treatment groups were treated with a dose equivalent to 2 pellets and 0.5 mL per kg of body weight respectively. Out-of-season spawning and reproduction after a sudden increase in water temperature were also examined. No control fish ovulated although in both years, fish treated with Ovaprim showed a higher percentage of ovulation (75–88%) and embryo survival to the eyed-egg-stage (69–78%) than those treated with Ovopel (ovulation 25–38%; embryo survival 36–47%). The latency time was shorter in the groups where Ovopel was applied (40–42 h) than in Ovaprim groups (42–48 h). Similar results were obtained in out-off-season spawning. After a sudden increase in water temperature, females treated with Ovopel did not ovulate. This indicates that Ovaprim might be successfully used for artificial reproduction of asp by applying the induction protocol and the conditions reported in the present study.