The effect of sublethal concentrations of Cu, Pb, Cd and Hg on larval development of Portunus trituberculatus
Cu、Pb、Cd、Hg亚致死浓度对三疣梭子蟹幼体的影响

To understand the effect of heavy metals on Portunus trituberculatus, larvae were exposed to varying concentrations of Cu, Pb, Cd and Hg. In the test group with Cu concentration at half the water quality standard for fisheries (0.005 mg·L-1), the crab larvae developed to the secondary stage of juvenile crab, while the test group at 0.01 mg·L-1 Cu, also developed to the secondary stage of juvenile crab, but all died by the 19th day of the experiment. In the test group with Pb concentrations at 1/2 the water quality standard for fisheries (0.025 mg·L-1), the crab larvae developed to the secondary stage of juvenile crab normally; and the group exposed to the maximum allowed concentration(0.05 mg·L-1), also developed to the secondary stage of juvenile crab, but died on the 20th day of the experiment. For Cd, the test group at 1/4 the water quality standard for fisheries (0.00125 mg·L-1), developed to the secondary stage of juvenile crab normally and the group at 1/2 the standard concentration (0.0025 mg·L-1), developed to the first stage of juvenile crab, but did not develop to the secondary stage of juvenile crab before the end of the experiment; For Hg, the test group exposed to levels at the water quality standard for fisheries (0.0005 mg·L-1), the crab larvae developed normally to the secondary stage of juvenile crab but the group with twice that concentration(0.001 mg·L-1) only developed to the first stage of juvenile crab before they all died. These results indicate that it is relatively secure to breed larvae of Portunus trituberculatus below the 1/2 times of water quality standard for fisheries of Cu (0.005 mg·L-1) and Pb (0.025 mg·L-1), 1/4 times of Cd(0.00125 mg·L-1) and Hg(0.000125 mg·L-1).