Nguyen Tam Thanh, Berg Håkan, Nguyen Loi Ngoc, Nguyen Yen Thi Hai, Nguyen Cong Van
Faculty of Fisheries, Nong Lam University, Ho Chi Minh City 700000, Vietnam.
Department of Physical Geography, Stockholm University, SE-106 91 Stockholm, Sweden.
Toxics. 2024 Dec 25;13(1):12. doi: 10.3390/toxics13010012.
This study assessed the effects of fenobucarb (F) (1%, 10%, and 20% of the LC-96h value) on the brain cholinesterase (AChE) activity, food intake (FI), feed conversion rate (FCR), and growth of silver barb (, Bleeker, 1849). It also assessed the AChE inhibition levels that cause the abnormal swimming, behavior, and mortality of silver barb and how the feeding regime affects the recovery rate of the AChE activity. The results showed that the brain AChE inhibition increased with the F concentrations. It peaked after nine hours, at 73.6% and 79.7% for the two highest concentrations, and then the AChE activity started to recover. After 96 h, the inhibition level was still 11.8% in the fish exposed to the two lowest concentrations and 30.5% in the fish exposed to the highest concentrations. Even when placed in clean water, the inhibition level in the fish that were exposed to the highest concentrations and only fed every third day was 32% after 14 days. Although there were no differences in the feed intake at any time, the fish exposed to F had a higher FCR and a lower specific growth rate and weight compared to the control fish at the later stages of the experiment. Thus, although the use of F in rice farming in the Mekong Delta may not lead to direct fish kills, it impacts the growth and health of the fish, which could have negative implications for wild fish populations and the long-term production of healthy fish in the Mekong Delta.
本研究评估了仲丁威（F）（LC-96h值的1%、10%和20%）对似野结鱼（Bleeker，1849）脑胆碱酯酶（AChE）活性、摄食量（FI）、饲料转化率（FCR）和生长的影响。还评估了导致似野结鱼异常游泳、行为和死亡的AChE抑制水平，以及投喂方式如何影响AChE活性的恢复率。结果表明，脑AChE抑制率随F浓度的增加而升高。9小时后达到峰值，两种最高浓度下分别为73.6%和79.7%，然后AChE活性开始恢复。96小时后，暴露于两种最低浓度的鱼的抑制水平仍为11.8%，暴露于最高浓度的鱼的抑制水平为30.5%。即使置于清水中，暴露于最高浓度且每隔三天投喂一次的鱼在14天后的抑制水平仍为32%。尽管在任何时候摄食量都没有差异，但在实验后期，与对照鱼相比，暴露于F的鱼的饲料转化率更高，特定生长率和体重更低。因此，尽管在湄公河三角洲的水稻种植中使用F可能不会直接导致鱼类死亡，但它会影响鱼类的生长和健康，这可能对野生鱼类种群以及湄公河三角洲健康鱼类的长期生产产生负面影响。
