Acute Toxic Effects of NaNO_2 on Portunus trituberculatus Larvas

Experimental crabs were chosen from the next day after each development stage.The result showed that: 72 h LC50 of NaNO2 was 2.282 mg/L and 2.736 mg/L respectively for Z1 of Portunus trituberculatus larvas in starvation and satiation,and 9.955 mg/L and 11.541 mg/L,19.487 mg/L and 30.336 mg/L,14.243 mg/L and 15.568 mg/L,69.110 mg/L and 126.020 mg/L respectively for Z2,Z3,Z4 and M of Portunus trituberculatus larvas;there was no remarkable diversity between the starvation group and satiation ones;the content of NaNO2 should be kept less than 0.228 mg/L in the breeding pond of Portunus trituberculatus larvas.Finally,the thesis discussed the acute toxic effects and reasons of NaNO2 on the juvenile of Portunus trituberculatus larvas.