Sexual maturity, reproductive behaviour and fertility in the first-generation hybrids of Blicca bjoerkna L. x Abramis brama L.

Sexual maturity, reproductive behaviour and fertility in the artificial first-generation hybrids of silver bream, Blicca bjoerkna, and common bream, Abramis brama, were investigated in this study. The results revealed that the females and males of hybrids attained their first sexual maturity at the same age. Maturity in F, hybrids was observed at the same moment as maturity in the common bream, the latter being the parental species. Sizes of male hybrids at maturity were intermediate to their parents but female hybrids were closer to the highest parental species, the common bream. As for reproductive behaviour, the numbers of spawning and mating behaviours observed were highly similar. Female hybrids mated simultaneously and successively with all types of males, except the common bream male. resulting in fertilised eggs. Male hybrids exhibited aggressiveness and territorial activities as in parental species common bream. Successful survival was observed in all post-F-1 (F-2 and backcross) generations at each developmental stage, proving that these hybrids are fertile