Controlled reproduction of chub, Leuciscus cephalus (L.) in captivity

The chubs studied in this experiment hatched after artificial fertilization of wild spawners. Young chubs were reared in captivity and submitted to high temperatures (20-25°C), natural photoperiod, and maximum feeding level. These environmental conditions resulted in an accelerated growth rate, bringing the males (n=60) to 72 g (mean weight) and the females (n=71) to 143 g in 2 years. At that moment, it was possible to induce (injection of carp pituitaries extracts) the first ovulation in the females (the males matured spontaneously) and to carry out artificial fertilization. In the culture system, females reached sexual maturity very early (January as compared to May-June in the river). The optimal rearing conditions allowed three reproductions to take place in 1 year (in January, June and July).