Study on the Embryonic and Early Larval Development of Rhinogobio ventralis

Abstract:

The current study investigated the embryonic and early larval development of Rhinogobio ventralis using the micro electronic imaging technology. The running-water hatching way was used to incubate the fertilized egg. The hatching water temperature was 17.6-18.3℃ and DO was 7-9 mg/L. The results showed that the range of R.ventralis egg diameter，egg membrane diameter and egg weight was 1.7-1.9 mm, 6.6-7.0 mm and 0.0059-0.0077 g, respectively, and that the life and swirling movement time of sperm were 96.56-119.12 s and 25.43-31.43 s, respectively. The time period for embryonic development was 56 h at 17.6-18.3℃. Eight embryo development stages of R.ventralis were described, which included fertilized egg, blastoderm, cleavage, blastula, gastrula, neurula, organogenesis, and hatching period. The yolk-sac of larvae disappeared after being reared for 5 days in the water at 18.5-22℃. The yolk-sac of 6-days age larvae disappeared completely, and the late larval stage began. The fin of 30-days age larva was basically formed and scales began to form. The growing larvae further developed into juvenile stage after 30 days. Our study provides theoretical basis and scientific reference for the mass reproduction of R.ventralis.