中美洲原产地鳗鲡苗种对几种生态因子的耐受性研究

初步研究了产自中美洲地区的美洲鳗鲡（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：鳗苗适宜水温是20℃～28℃，临界上限和下限分别是38℃及0℃；鳗苗正常活动的溶氧临界值是1.0 mg L-1，半数窒息点为0.7 mg L-1；适宜pH为4～10，耐受的上下限分别为11和3；非离子态氨对鳗苗24、48、72、96h的半致死浓度分别是4.54、4.08、4.08、2.62 mg L-1，安全浓度为0.26 mg L-1；亚硝酸盐对鳗苗24、48、72、96h的半致死浓度分别是92.05、65.81、45.54、37.06 mg L-1，安全浓度为3.71 mg L-1；引起鳗苗不安的光强阈值是5.88 µE/m2/s。

Tolerance of Anguilla rostrata from Central America to Several Ecological Factors

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 ammonia and nitrite.The results showed that appropriate water temperature for A.rostrata was from 20 to 28℃,with upper critical temperature 38℃ and lower critical temperature 0℃.The critical value of dissolved oxygen concentration 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 LC50 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 LC50 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 μE/m2·s.