We evaluated the use of measurements of length and mass to predict larval metamorphosis of Pacific lamprey Entosphenus tridentatus. During 2004-2008, larval E. tridentatus were collected from Cedar Creek (Washington, USA) in either the spring or autumn, measured for total length and total mass, reared in captivity and monitored for metamorphosis. The minimum total length, total mass and condition factor of larvae that were observed to go through metamorphosis were 102 mm, 2.0 g and 1.52, respectively. Logistic models indicated that total length and condition factor in both spring and autumn were the most significant variables for predicting metamorphosis of Pacific lamprey during the subsequent summer. However, mass in the autumn also appeared important to whether metamorphosis occurred the subsequent summer. Collectively, all models using specific minimums of total length, total weight or condition factor of larvae as criteria for them to metamorphose were sometimes (5 of 14 cases) able to predict the percent of larvae that would metamorphose but rarely (1 of 12 cases) able to predict which individual larvae would metamorphose. Similar to other anadromous species of lampreys, the size and condition of larval E. tridentatus have utility for predicting metamorphic fate. This article is protected by copyright. All rights reserved.

中文翻译：

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通过测量长度和质量预测太平洋七鳃鳗Entosphenus tridentatus的幼虫变态

我们评估了使用长度和质量测量来预测太平洋七鳃鳗 Entosphenus tridentatus 的幼虫变态。2004-2008 年期间，在春季或秋季从 Cedar Creek（美国华盛顿）收集幼虫 E. tridentatus，测量总长度和总质量，圈养饲养并监测变态。观察到经历变态的幼虫的最小总长度、总质量和条件因子分别为102 mm、2.0 g和1.52。Logistic 模型表明，春季和秋季的总长度和条件因子是预测随后夏季太平洋七鳃鳗变态的最重要变量。然而，秋季的质量对于随后的夏季是否发生变态也很重要。总的来说，所有使用幼虫总长度、总重量或条件因子的特定最小值作为它们变态标准的所有模型有时（14 个案例中的 5 个）能够预测会变态的幼虫的百分比，但很少（12 个案例中的 1 个）能够预测预测哪些个体幼虫会变态。与七鳃鳗的其他溯河物种类似，三齿鳗幼虫的大小和状况可用于预测变质命运。本文受版权保护。版权所有。E. tridentatus 幼虫的大小和状况可用于预测变质命运。本文受版权保护。版权所有。E. tridentatus 幼虫的大小和状况可用于预测变质命运。本文受版权保护。版权所有。