Peculiarities of grass carp (Ctenopharyngodon idella) embryonic development under conditions of artificial reproduction in Uzbekistan

Embryonic development of grass carp (Ctenopharyngodon idella) was studied; the species was introduced from China to Uzbekistan in the early 1960s. More than 10 generation changes were taken place in local conditions. Artificial reproduction by using gonadotropic stimulation of ripening and eggs incubation is main method to provide reproduction of the species in the country. Embryonic development passed normally. A blastodisc division begin during the first hour after fertilization, stages of morula - after 2 hours, blastula - 3.5 hours, gastrula - 4 hours, organogenesis - 14 hours, larvae hatching occurs after 34 hours after fertilization at water temperature 21-23oC, transition to mixed feeding of larvae - after 4 hours, to exogenous feeding - after 5 days. Embryonic development rate is some higher than in 1960-1980s in local conditions and higher than in the river Yangtze. Construction of water supply in hatchery provides more stable water temperature without noticeable changing in night.