中美洲原产地鳗鲡苗种对几种生态因子的耐受性研究

Tolerance of Anguilla rostrata from Central America to Several Ecological Factors

研究了中美洲原产地鳗鲡(Anguilla rostrata)苗种对于温度、pH值、溶解氧、亚硝酸盐、氨氮、光强等生态因子的适宜范围及耐受极限。结果显示,中美洲鳗鲡白仔苗的适宜水温为20～28℃,临界上限水温38℃、下限水温0℃;其正常活动的溶氧临界值为1.00mg/L,半数窒息点为0.70mg/L;适宜pH为4～10,耐受上限为pH11、下限为pH3;非离子态氨对鳗鲡白仔苗24、48、72、96h的半致死浓度分别为4.54、4.08、4.08、2.62mg/L,安全浓度0.262mg/L;亚硝酸盐对鳗鲡白仔苗24、48、72、96h的半致死浓度分别为92.05、65.81、45.54、37.06mg/L,安全浓度为3.71mg/L;引起鳗鲡白仔苗不安的光强阈值为5.88μE/m2·s。

This experiment was designed to investigate the tolerance of Anguilla rostrata from Central America to several ecological factors such as water temperature, pH, dissolved oxygen, light intensity and acute toxicity of am- monia and nitrite. The results showed that appropriate water temperature for A. rostrata was from 20 to 28 ~C, with upper critical temperature 38~C and lower critical temperature 0℃. The critical value of dissolved oxygen concen- tration for normal activity of A. rostrata was 1.00 mg/L, and the half suffocation value was 0.70 mg/L. Appropriate pH value varied from 4 to 10, with upper critical limit 11 and lower critical limit 3. 24 h, 48 h, 72 h and 96 h LCs0 of nonionic ammonia to A. rostrata were 4.54 mg/L, 4.08 mg/L, 4.08 mg/L and 2.62 mg/L respectively, with its safe concentration 0. 262 mg/L. 24 h, 48 h, 72 h and 96 h LC^o of nitrite to A. rostrata were 92.05 mg/L, 65.81 mg/L, 45.54 mg/L and 37.06 mg/L respectively with its safe concentration 3.71 mg/L. In addition, the threshold value of light intensity causing inquietude of A. rostrata was 5.88 I.LE/m^2 · s.