氨对褶纹冠蚌钩介幼虫及稚蚌的急性毒性

ACUTE TOXICITY OF AMMONIA TO GLOCHIDIA AND NEWLY TRANSFORMED JUVENILE OF CRISTARIA PLICATA

  • 摘要: 为探究氨对蚌类早期生活史阶段的毒性效应, 研究分别以褶纹冠蚌(Cristaria plicata)的钩介幼虫及稚蚌为实验对象开展了24h和48h的急性毒性实验。结果表明: 氨对褶纹冠蚌钩介幼虫的24h半致死浓度(LC50)为0.63 mg NH3-N/L (NH3, 分子氨)和78 mg TAN7.0, 20℃/L (TAN7.0, 20℃, pH 7.0水温20℃时即标准化的总氨氮); 氨对褶纹冠蚌稚蚌的48h LC50为0.60 mg NH3-N/L和104 mg TAN7.0, 20℃/L; 上述阈值高于已有研究中氨对其他淡水蚌类的毒性阈值; 褶纹冠蚌钩介幼虫对氨氮的耐受性低于稚蚌, 二者均低于幼蚌, 因此褶纹冠蚌更早期生活史阶段对氨的耐受性更低。相关研究结果可完善氨对蚌类毒性的理解, 为水体氮管理策略的制定和蚌类保护提供一定科学依据。

     

    Abstract: To investigate the toxic effects of ammonia on the early life history stages of mussels, we selected glochidia and newly transformed juveniles of Cristaria plicata, a common mussel species in the middle and lower reaches of the Yangtze River, and conducted 24h and 48h acute toxicity tests to assess the effects. The results showed that: the 24h lethal concentration of 50% (LC50) of ammonia in glochidia of Cristaria plicata was 0.63 mg NH3-N/L (NH3-N, unionized–ammonia nitrogen) or 78 mg TAN7.0, 20℃/L (TAN, standardized total ammonia nitrogen that pH 7.0 and water temperature of 20℃). The 48h LC50 of ammonia in newly transformed juveniles of Cristaria plicata was 0.60 mg NH3-N/L or 104 mg TAN7.0, 20℃/L. The LC50 of ammonia to Cristaria plicata was higher compared to other freshwater mussels species reported both domestically and internationally. The early life stages of Cristaria plicata were more sensitive to ammonia compared to the later life history stages. The results of this study contribute to a better understanding of ammonia toxicity on mussels and provide a scientific basis for mussels conservation and water nitrogen management strategy.

     

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