Rates of oxygen consumption and tolerance of hypoxia and desiccation in Chinese black sleeper(Bostrichthys sinensis) and mudskipper(Boleophthalmus pectinirostris) embryos

The rates of oxygen consumption, tolerance of hypoxia and desiccation of the Chinese black sleeper (Bostrichthys sinensis) and mudskipper (Boleophthalmus pectinirostris) embryos were investigated. The pattern of oxygen consumption of the Chinese black sleeper embryos was similar to that of the mudskipper ones. The lowest rates of oxygen consumption[(1.65±0.66)nmol/(ind.·h)] of the Chinese black sleeper embryos 16 h after fertilization and the lowest rates of oxygen consumption[(0.79±0.08)nmol/(ind.·h)] of the mudskipper embryos 6 h after fertilization were recorded, respectively. Then the rates of oxygen consumption of these two species embryos increased gradually until hatching[(8.26±1.70)nmol/(ind.·h)in the Chinese black sleeper, (2.69±0.23)nmol/(ind.·h) in mudskipper]. After exposure to hypoxia water (0.16 mg/dm³), bradycardia of the embryos occurred in both the Chinese black sleeper and the mudskipper. However, the Chinese black sleeper embryos survived approximately 45 min longer than the mudskipper ones. After exposure to desiccation at a relative humidity of 58%, bradycardia of the embryos was observed in both the Chinese black sleeper and the mudskipper, and the Chinese black sleeper embryos lived approximately 9 min longer than the mudskipper ones.