HAN Xiao-lin1,2, WANG Hao-feng2,3, GAO Bao-quan2, LIU Ping2,CHEN Ping2, LI Jian2, LI Hua1
1. College of Fisheries and Life Science,Dalian Ocean University, Dalian 116023, China; 2. Key Laboratory for Sustainable Development of Marine Fisheries Resources, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; 3. College of Fisheries, Ocean University of China, Qingdao 266003, China
Abstract: The survival rate, metamorphosis rate and growth were studied in swimming crabPortunustrituberculatusjuveniles in two groups (“Huangxuan No.1” and low salinity group) under low salinity of 11.7, the median lethal salinity (LD50) for 120 h based on low salinity stress experiment in the wild crab stocks. The results showed that the “Huangxuan No.1” had significantly lower survival rate at a salinity of 11.7 than that at a salinity of 35.0. The juveniles in the low salinity group, however, showed almost the same survival rate at a salinity of 11.7 as that at a salinity of 35.0. There were significantly lower metamorphosis rate and growth in the two crab groups at a salinity of 11.7 than at a salinity of 35.0. At the end of the experiment, the “Huangxuan No.1” juveniles exposed to salinity of 11.7 had survival rate of 20.00%, metamorphosis rate of 10.00%, and total carapace width of (17.47±1.11)mm. However, the “Huangxuan No.1” juveniles exposed to a salinity of 35.0 showed survival rate of 52.22%, metamorphosis rate of 53.33%,and total carapace width of (20.43±1.21)mm. The swimming crab juveniles in the low salinity group exposed to a salinity of 11.7 had survival rate of 32.22%, metamorphosis rate of 13.33%, total carapace width of (17.69±0.93)mm and body weight of (0.35±0.06)g. The juveniles of the low salinity group exposed to a salinity of 35.0 showed survival rate of 27.98%, metamorphosis rate of 16.67%, and total carapace width of (18.79±1.61)mm. There was higher tolerance to low salinity in the juveniles of the low salinity group, and the “Huangxuan No.1” juveniles were found to be superior to the low salinity group at a salinity of 35.0 in survival, metamorphosis rate, and total carapace width.
2014, Vol. 29 
