SPAWNING PERFORMANCE AND DEVELOPMENT OF OOCYTES IN GOBIOCYPRIS RARUS

Twenty pairs of laboratory-reared F1 and F3 of Gobiocypris rarus were used to study spawning performance and development of oocytes. Analyses of spawning performance and ovum diameter histograms demonstrated that females produced clutches of eggs. In Stage V ovaries, the number of eggs in final clutch that contains mature and ripe eggs represents the present batch fecundity. Every a few days, such a final clutCh could be produced and spawned by mature females.Recruitment of oocytes is so fast that primary recruitment pool can be renewed in 13 to 33 days. Based on spawning frequency and ovum development it was confirmed that the process of eggs' recruitment is continuous. A total of 273 spawnings were observed in 20 pairs kept at 21.61±3.0℃ in the laboratory. The interspawning intervals ranged from 2 to 9 days, with a mean of 4.5 days and a mode of 4 days.The batCh size ranged from 96 to 655 eggs with a mean of 265.6 eggs for females of 47.6 to 56.0 mm total length. This paper proved that Gobiocypris rarus is a continuous batch spawner.