Application of dopaminergic antagonist: Metoclopramide, in reproduction of crucian carp Carassius carassius (L.) under controlled conditions

• Successful reproduction of crucian carp using a dopamine antagonist i.e. metoclopramide was confirmed.
• Eggs production and its quality after metoclopramide application was analyzed.
• Sperm characteristics after metoclopramide application was described using CASA system.
• Application of metoclopramide in artificial reproduction of cyprinids was reviewed and discussed.

The effectiveness of Ovopel (two pellets/kg body weight), a complex of [D-Ala6 Pro9NEt-mGnRH] and dopamine antagonist (DA e.g. Metoclopramide, MET), was compared with the application MET alone at the dose of 20 mg/kg body weight in spawning crucian carp Carassius carassius (L.) in the present study. Ovulation and spermation rates were greater after MET application (90% and 100%, respectively) in comparison to the Ovopel (80% and 87.5%, respectively) when used as a broodstock reproductive stimulation agent. Sperm quality (CASA parameters) after MET treatment was very acceptable without a significant decrease in comparison to the samples from Ovopel-treated crucian carp when spermation stimulation treatments were employed. Though there were no differences in egg and sperm production between Ovopel and MET treatments, hatching rates were significantly greater after MET (84.4%) compared with Ovopel (76.2%) treatment. The usefulness of MET application without GnRHa addition for stimulation of reproduction was ascertained in the present study for the first time in crucian carp.