Embryonic development of the striped spiny eel, Mastacembelus pancalus (Hamilton, 1822) in captive condition

The striped spiny eel, Mastacembalus pancalus is one of the common food fish in Bangladesh, but lacking study on embryonic development of the fish. The present study describes the embryonic progress stages of the fish in the confined state. The embryogenesis is divided into seven major phases: Zygote phase, Cleavage phase, Morula phase, Blastula phase, Gastrula phase, Organogenesis phase and Hatching phase. According to distinct development characteristics, the further substages were also developed whenever possible. Fertilized eggs were sticky, colorless, and demersal with identical perivitelline space. The thickness of the unfertilized eggs ranged from 0.55-0.58 mm, which increased to 0.62-0.71 mm in fertilized eggs. The perivitelline space development happened at 0.35 h after fertilization (AF). The first cleavage groove occurred…