Tessier Laura R, Long Tristan A F, Wilkie Michael P
Department of Biology and Laurier Institute for Water Science, Wilfrid Laurier University, 75 University Ave West, Waterloo, ON, N2L 3C5, Canada.
Department of Biology and Laurier Institute for Water Science, Wilfrid Laurier University, 75 University Ave West, Waterloo, ON, N2L 3C5, Canada.
Aquat Toxicol. 2018 Jan;194:27-36. doi: 10.1016/j.aquatox.2017.10.020. Epub 2017 Oct 28.
Invasive sea lamprey (Petromyzon marinus) are controlled in the Great Lakes using the lampricide 3-trifluoromethyl-4-nitrophenol (TFM), which is applied to streams infested with larval lamprey. However, lamprey that survive treatments (residuals) remain a challenge because they may subsequently undergo metamorphosis into parasitic juvenile animals that migrate downstream to the Great Lakes, where they feed on important sport and commercial fishes. The goal of this study was to determine if body size and life stage could potentially influence sea lamprey tolerance to TFM by influencing patterns of TFM uptake and elimination. Because mass specific rates of oxygen consumption (M˙O) are lower in larger compared to smaller lamprey, we predicted that TFM uptake would be negatively correlated to body size, suggesting that large larvae would be more tolerant to TFM exposure. Accordingly, TFM uptake and M˙O were measured in larvae ranging in size from 0.2-4.2g using radio-labelled TFM (C-TFM) and static respirometry. Both were inversely proportional to wet mass (M), and could be described usingthe allometric power relationship: Y=aM, in which M˙O=1.86M and TFM Uptake=7.24M. We also predicted that body size would extend to rates of TFM elimination, which was measured following the administration of C-TFM (via intraperitoneal injection). However, there were no differences in the half-lives of elimination of TFM (T -TFM). There were also no differences in M˙O or TFM uptake amongst size-matched larval, metamorphosing (stages 6-7), or post-metamorphic (juvenile) sea lamprey. However, the T-TFM was significantly lower in larval than post-metamorphic lamprey (juvenile), indicating the larval lamprey cleared TFM more efficiently than juvenile lamprey. We conclude that larger larval sea lamprey are more likely to survive TFM treatments suggesting that body size might be an important variable to consider when treating streams with TFM to control these invasive species.
在五大湖地区，人们使用杀鳗剂3 - 三氟甲基 - 4 - 硝基苯酚（TFM）来控制入侵的海七鳃鳗（海七鳃鳗），该药剂被应用于受海七鳃鳗幼体侵扰的溪流。然而，经处理后存活下来的七鳃鳗（残留个体）仍是一个难题，因为它们随后可能会变态发育成寄生性幼体动物，向下游洄游至五大湖，以重要的游钓鱼类和商业鱼类为食。本研究的目的是确定体型和生命阶段是否可能通过影响TFM的摄取和消除模式来影响海七鳃鳗对TFM的耐受性。由于与较小的七鳃鳗相比，较大的七鳃鳗单位质量的耗氧率（M˙O）较低，我们预测TFM的摄取与体型呈负相关，这表明大型幼体对TFM暴露的耐受性更强。因此，使用放射性标记的TFM（C - TFM）和静态呼吸测定法，对体重在0.2 - 4.2克范围内的幼体进行了TFM摄取和M˙O的测量。两者均与湿重（M）成反比，并且可以用异速生长幂关系来描述：Y = aM，其中M˙O = 1.86M，TFM摄取量 = 7.24M。我们还预测体型会影响TFM的消除速率，这是在注射C - TFM（通过腹腔注射）后进行测量的。然而，TFM消除半衰期（T -TFM）没有差异。在体型匹配的幼体、变态期（6 - 7阶段）或变态后的（幼体）海七鳃鳗之间，M˙O或TFM摄取也没有差异。然而，幼体七鳃鳗的T -TFM显著低于变态后的七鳃鳗（幼体），这表明幼体七鳃鳗清除TFM的效率高于幼体七鳃鳗。我们得出结论，较大的幼体海七鳃鳗更有可能在TFM处理中存活，这表明在使用TFM处理溪流以控制这些入侵物种时，体型可能是一个需要考虑的重要变量。
