Out-of-season artificial reproduction of common dace (Leuciscus leuciscus L.) under controlled conditions

This study focused on the artificial reproduction of common dace Leuciscus leuciscus (L.) outside the reproductive season. The results indicate there is the possibility of initiating the reproducion in individuals of this before the natural spawning season. There could be induction of spermiation by altering the environmental conditions. For females, hormonal injections were necessary for induction of final oocyte maturation and ovulation. Generally, there were high percentages of spermiation (100%) and ovulation (87%-100%) as well as low mortality (0%-11% and 7%-13% for males and females, respectively) among the induced spawners. The greatest embryo survival occurred when Ovaprim (84.4%) or hCG (89.6%) was administered, although the latency time using hCG was at least twice as long compared to when other spawning agents were used (84-92 hrs and 30-44 hrs). The results from present study could be applicable for optimization of breeding stock numbers in aquaculture enterprises and in providing insights for conservation of L. leuciscus endangered populations.