Effects of salinity on reproductive performance of Eriocheir sinensis
The effects of salinity on the reproductive performance of Eriocheir sinensis were studied to establish the minimum salinity and appropriate salinity range for mating,oviposition and embryo hatching.Female and male E.sinensis were placed in water of different salinities.After mating and spawning,anatomical samples were taken,and embryos were taken out and incubated with different salinities.The mating rate,spawning rate,reproductive performance of E.sinensis parents under different salinities were compared.The results showed that:1)E.sinensis failed to mate at salinity 0(fresh water).At salinity 1,E.sinensis could mate,but the mating rate was low,only(6.67±5.77)％.At salinity 4,the mating rate increased significantly to(70.00±14.14)％,and there was a significant difference(P＜0.05).The minimum salinity of E.sinensis spawning was 6,and the spawning rate was(40.97±4.91)％,significantly different from other groups(P＜0.05).At salinity 21,the mating rate was the highest,close to 100％,and the suitable salinity range for spawning was 9-21;2)In salinity range of 0-21,At salinity 0,the embryos could continue to develop,but did not hatch.The hatching rate at other salinities increased gradually with the extension of time.At salinity 15,the hatching rate of embryos was the highest,reached(70.00±5.23)％;3)At salinity 0,HSI and GSI of females were(7.76±1.05)％and(10.46±1.29)％respectively;at salinity of 2-8,HSI of females after mating did not change significantly(P＞0.05);at salinity 8,GSI of females was 0,significantly different from other groups(P＜0.05).At salinity of 0-8,HSI and GSI of males after mating were lower than those before mating.There was no significant change in HSI among salinity groups,while GSI had a downward trend;4)At salinity of 6-21,with the increase of salinity,the egg production,reproductive effect and fecundity increased first and then decreased.At salinity 6,the egg production and reproductive effect of spawning E.sinensis were the lowest(P＜0.05),with an average of(13.26±2.99)× 104 and(5.47±1.70)％respectively.At salinity 18,the egg production,reproductive effect and fecundity of female E.sinensis reached the peak,which were(31.83±2.61)×104,(11.45±1.70)％and(0.51±0.05)×104·g-1respectively,and there were significant differences with other salinity groups(P＜0.05).In conclusion,the lower salinity limits of mating and spawning of E.sinensis are 1 and 6,the salinity range suitable for mating is 4-21,and the salinity range suitable for spawning is 9-21.The optimum hatching salinity of embryos from gastrula stage is 15,and the suitable hatching salinity range is 12-18;the reproductive performance of E.sinensis is the best at salinity 18.The research shows that the change of water salinity has a certain impact on the mating,spawning and embryo hatching of parent E.sinensis,and it establishes the minimum salinity and appropriate salinity range for the mating,spawning and embryo hatching of E.sinensis,providing basic data for research on the breeding biology of E.sinensis,and scientific basis and reference for the rational division of breeding grounds of E.sinensis in the Yangtze River Estuary.
万方数据
维普
