A preliminary study on artificial propagation and embryonic development of Discogobio yunnanensis

Discogobio yunnanensis with good gonadal development were investigated by artificial spawning, dry fertilization and fertilized by dry artificial insemination, being injected with mixture of human chorionic gonadotropin (HCG), luteinizing hormone releasing hormone A₂ (LHRH-A₂) and domperidone (DOM).The morphological traits and developmental time of embryonic developmental stages were recorded in great details by stereomicroscope.Results show that the yellow-green eggs of D.yunnanensis were spherical, pelagic, slightly adhesive with an average diameter of 2.1 mm, and 3.29 mm after absorbing water.The time for embryonic development was 168 h 30 min when the water temperature was 17~19 ℃.The embryonic development of D.yunnanensis can be divided into 27 development phases and six stages, including fertilized eggs period, cleavage period, blastula period, gastrula period, neurula and organogenetic period.The average length and weight of the newly hatched fry were 7.16 mm and 0.012 g, respectively.The newly hatched larvae were almost developed completely, with a bigger yolk sac, an obvious branchial circulation, a rudiment of mouth and a ureter near the cloacal orifice.