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JOE_橙痕

银虫 (小有名气)

应助: 2 (幼儿园)
金币: 173.4
帖子: 81
在线: 30.7小时
虫号: 2370317
注册: 2013-03-23
性别: GG
专业: 生物海洋学与海洋生物资源

[求助] 英文摘要求大神修改，给出指点意见

本实验采用氨态氮与亚硝态氮耦合、亚硝态氮与盐度耦合和氨氮与pH耦合三组环境胁迫对凡纳滨对虾的生长及摄食进行亚慢性毒理实验。氨态氮梯度设置为0、5、10 mg/L三个水平，亚硝态氮水平梯度为0、5、10 mg/L，pH梯度设置为7.6、8.2、8.8，盐度的梯度设置为5、15、25三个水平。通过每天都给予恒定剂量的氮，连续培养7天后，对虾的特定生长速率、摄食率和饲料转化率均随着氨氮或亚硝态氮的增高而降低（P<0.05）。最高浓度的氨态氮（10mg/L）与亚硝态氮（10mg/L）组与对照组相比较，特定生长率、摄食率和饲料转化率分别下降了18.31%，14.68%和17.49%。当氨态氮作为氮添加的情况下，pH7.6和pH8.8的参数均要低于pH8.2（P<0.05）。但高pH能进一步加剧氨态氮的毒性，pH8.8的存活率显著低于pH7.6和8.2（P<0.05），且pH8.8和氨态氮10 mg/L的对虾在实验第二天全部死亡。当亚硝态氮作为氮添加时，盐度对摄食率并无显著影响（P>0.05），但对特定生长率和饲料转化率影响显著（P<0.05）。在亚硝态氮10 mg/L时，盐度15和25的特定生长率、饲料转化率和存活率均高于盐度5。结果表明高盐度能够缓解亚硝态氮对于对虾生长的抑制，而高pH则会加剧氨态氮对于对虾的毒性。

In this study, sub-chronic toxicological experiments were carried out on the growth and feeding of Litopenaeus vannamei by coupling ammonia-nitrogen with nitrite-nitrogen, coupling with nitrite-N and salinity, and coupling with ammonia-N and pH. The gradient of ammonia-N is set to 0, 5, 10 mg/L, the gradient of nitrite is 0, 5, 10 mg/L, the pH gradient is set to 7.6, 8.2 and 8.8, and the gradient of salinity is 5, 15, 25. After 7 days of culture, the growth and feed intake parameters decreased as the increasing concentration of nitrite-N or ammonia-N under nitrite-N and ammonia-N treatments (P<0.05). Comparing with control treatment, the specific growth rate, feed intake and feed conversion rate decreased 18.31%, 14.68% and 17.49% in highest concentration of ammonia-N and nitrite-N, respectively. In the culture with ammonia-N as exclusive N source addition, the parameters of pH7.6 and pH8.8 were significantly lower than that of pH7.6 (P<0.05). Furthermore, the survival rate of pH8.8 was lower than both of pH 7.6 and pH8.2 (P<0.05), and all individuals died on the second day in the pH 8.8 and 10 mg/L ammonia-N treatment, suggesting that high pH value will enhance the negative effects induced by ammonia-N to L. vannamei. In the culture with nitrite-N as exclusive N source addition, the salinity had no influence on feed intake (P>0.05), but had significant effects on the specific growth rate and feed conversion (P<0.05). when the concentration of nitrite-N reached 10 mg/L, the specific growth rate, feed conversion and survival rate of both salinity 15 and salinity 25 were higher than that of salinity 5 (P<0.05). The result showed that high salinity could alleviate the inhibition of nitrite-N on growth, while high pH value would exacerbate the toxicity of ammonia-N to L. vannamei.

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