1.Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; 2.Sino-US Cooperative Laboratory for Germplasm Conservation and Utilization of Freshwater Mollusks, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; 3.Fishery Development Center of Fuyang City, Fuyang 236001, China; 4.Anhui Shuiyun Environmental Protection Company Limited, Wuhu 241000, China
Abstract: In order to explore possibility of freshwater mussel Solenaiaoleivira culture in coastal NaCl saline alkali land or tidal flat, the survival test was carried in the freshwater mussel juveniles with wet body weight of (2.63 g± 0.47 g) exposed to acute stress of fresh water (0.20) and high salinity of 2.00, 3.31, 3.70, 4.24, 4.92, 5.82, and 7.00 using the equal log interval method and 50% of the 96 h half lethal salinity (LC50) as the tolerant salinity. The oxygen consumption rate, ammonia excretion rate, food intake rate and fecal excretion rate were measured in freshwater mussel exposed to these salinities by the indoor hydrostatic method, and then the energy budget equation was established at water temperature of (22±1)℃. The results showed that the dead mussel was observed at salinity of 2.00 at 72 h, and at salinity of 7.00 within 48 h, with LC50 of 4.47 at 96 h. There were significantly higher oxygen consumption rate, ammonia excretion rate, food intake rate, water filtration rate and fecal excretion rate (P<0.05), with the decreased slightly lower absorption efficiency (P>0.05), in the juveniles at stress of high salinity (2.23) than those in the freshwater mussel in the fresh water group (P<0.05). Under high salinity (2.23) stress, the freshwater mussel had significantly higher energy used for respiratory metabolism and feeding metabolism, with increase in the proportion of respiratory energy (R), excretory energy (U) and fecal energy (F) in feeding energy (C), and significant decrease in the proportion of growth energy (P) in feeding energy. The energy budget equation was described as 100C=57.22R+9.49U+9.05F+24.23P under fresh water and 100C=62.55R+13.99U+12.05F+11.41P at high salinity (2.23) stress. The finding indicates that the juvenile firewater mussel S.oleivira has a poor tolerance to sodium salt which shows a significant impact on the respiratory metabolism and food metabolism of the mussel. The coastal NaCl type water is within saline alkali land or tidal flat water where the juvenile freshwater mussel culture should be at a salinity of less than 2.23.
2022, Vol. 37 
