Effects of temperature and salinity on hatching , survival and growth of amphipod crustacean （Eogammarus sinensis）

Eogammarus sinensis was reared at different temperatures, and salinities so as to analyze the effects of temperature and salinity on its hatching, survival and growth. E.sinensis were sampled from Haiyang shrimp cultural pond, Yantai city. The berried females were accustomed to the experimental conditions gradually as the females were pregnant. In the temperature experiment, the larvae were reared in beakers (the cubage of each was about 700 mL) at four temperatures (15, 20, 25, and 30℃). The results showed that the optimum temperature to the hatching was 20℃. The DG (daily growth) and the SGR (specific growth rate) of E.sinensis were significantly affected by temperature (P<0.01). The body length and body wet weight increased ranging from 15℃ to 25℃, and 25℃ was the optimum temperature to the larval growth. When the temperature is beyond 26, the growth was decreased. The above results suggested that E.sinensis was able to have higher biomass and productivity ranging from 20℃ to 25℃. According to correlation equations and calculation results, optimum incubation temperature is 21.50℃.On the other hand, the survival rate of larvae had no significant differences affected by temperature (P>0.05). In the salinity experiment, the animals were reared in the same beakers at seven salinities (5, 10, 15, 20, 25, 30 and 35). The number of larvae and the survival rate were both increased at first and reduced later in succession, so did the DG and SGR. There were no significant effects of salinity on the hatching, larval survival rate, the DG and SGR (P>0.05). Temperature and salinity interaction experiments showed that the E.sinensis had better ability to adapt to salinity, the development of its population was more affected by temperature than by salinity.