Effects of water temperature, salinity and pH on embryonic development of Selenotoca multifasciata

The characteristics of embryonic development of Selenotoca multifasciata under different temperature, salinity and pH were studied for the first time, to provide a reference for the selection and regulation of suitable conditions for seedling cultivation of S. multifasciata. The embryos of S. multifasciata were incubated at different temperatures (16, 20, 24, 26, 28, 30, 32, 34, 36 ℃), salinities (fresh water, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50) and pH (5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0). The results indicate that the hatching temperature of S. multifasciata was 24–36 ℃ at salinity of 32. With the increase of temperature, the hatching time descreased, and the hatching rate first increased and then decreased, while the deformity rate was on the contrary. The optimal hatching temperature was 26–28 ℃. At pH of 5.5–8.5, the hatching time descreased with the increase of pH. The hatching rate first increased and then decreased, while the deformity rate was on the contrary. The optimal hatching pH was 7.5–8.2. The larvae hatched out at salinity of 5–50. The hatching rate first increased and then decreased with the increase of salinity, while the deformity rate was on the contrary. The optimal hatching salinity was 25–29.