The Effects Of Salinity On Growth、Immune-related And Metabolism-related Enzymes Activity Of Portunus Trituberculatus "huangxuan No1"

The salinity tolerance experiments have been done on Portunus trituberculatus“Huangxuan No1”.The results show that the LD50values of crabⅡ juvenile for24、48、72h for tolerance to low-salinity were21.655、22.109、23.184，respectively, andfor tolerance to high-salinity were50.711、50.061、49.612respectively; the LD50values of80-days crabs for24、48、72h for tolerance to low-salinity were5.13、7.49、8.56，respectively,and for tolerance to high-salinity were54.49、52.74、52.21respectively. CrabⅡ juvenile can survive in6.7low-salinity water by gradual salinitychange,and can survive in47.7high-salinity water by gradual salinity change;while80-day crabs can survive in5.7low-salinity water by gradual salinity change,and cansurvive in47.7high-salinity water by gradual salinity change.The salinity gradients (8.7、13.7、18.7、23.7、28.7、33.7、38.7、43.7) were settedin In the Portunus trituberculatus “Huangxuan No1” survival salinity range.Then weraised the two kinds of specifications Portunus trituberculatus “Huangxuan No1”30days.After30days,we measured the weights、molting times、full carapace anddetected the immune-related enzymes and the metabolism related enzymes of gill,muscle, hepatopancreas, haemolymph. The results show that in the growthperformance,both80-days crab and crabⅡ juvenile have the largest weight growthand the most molting times in salinity18.7.80-days crabs have the fastest growth offull carapace in salinity18.7.howerver, crab Ⅱ juvenile have no Significantdifferences in different salinity gradients.In the immune-related enzymesperformance,1)Salinity has Significant differences in AKP activity of gill, muscle,haemolymph,but has no Significant differences in AKP activity of hepatopancreas.The AKP activity of gill, muscle, haemolymph are in the highest level in salinity8.7,then with the salinity increasing, The AKP activity of gill, muscle, haemolymphdropped gradutally.2) Salinity has no Significant differences in ACP activity of gill,muscle, haemolymph, hepatopancreas. ACP activity of hepatopancreas> ACPactivity of gill> ACP activity of muscle.3) Salinity has no Significant differences inLSZ activity of gill, muscle, haemolymph, hepatopancreas. LSZ activity of hepatopancreas> LSZ activity of muscle> LSZ activity of gill.4) Salinity has noSignificant differences in GSH content of gill, muscle, haemolymph, hepatopancreas.GSH content of hepatopancreas> GSH content of muscle> GSH content of gill..Inthe metabolism related enzymes performance, Salinity has Significant differences inNa~+K~+_ATPase activity of gill. The Na~+K~+_ATPase activity of gill descends fromsalinity8.7to salinity18.7, the Na~+K~+_ATPase activity is the lowest in salinity18.7,then the Na~+K~+_ATPase activity of gill rise from salinity18.7to salinity43.7.2)Salinity has no Significant differences in GS activity of gill,muscle,haemolymph,hepatopancreas. GS activity of gill> GS activity of muscle> GS activity ofhepatopancreas.Comprehensive comparison, Salinity has Significant effect on growthperformance of Portunus trituberculatus “Huangxuan No1”. Portunus trituberculatus“Huangxuan No1” grow best in salinity18.7. Salinity has Significant effect on mostof immune-related enzymes except AKP activity. In the metabolism related enzymesperformance, salinity has Significant effect on the Na~+K~+_ATPase activity,but has noSignificant effect on GS activity.A natural conclusion from the above discussion isthat Portunus trituberculatus “Huangxuan No1” grow best in salinity18.7.