An emerging consensus suggests that evolved intraspecific variation can be ecologically important. However, evidence that evolved trait variation within vertebrates can influence fundamental ecosystem-level processes remains sparse. In this study, we sought to assess the potential for evolved variation in the spotted salamander (Ambystoma maculatum) to affect aquatic ecosystem properties. Spotted salamanders exhibit a conspicuous polymorphism in the colour of jelly encasing their eggs—some females produce clear jelly, while others produce white jelly. Although the functional significance of jelly colour variation remains largely speculative, evidence for differences in fecundity and the morphology of larvae suggests that the colour morphs might differ in the strength or identity of ecological effects. Here, we assessed the potential for frequency variation in spotted salamander colour morphs to influence fundamental physiochemical and ecosystem properties—dissolved organic carbon, conductivity, acidity and primary production—with a mesocosm experiment. By manipulating colour morph frequency across a range of larval densities, we were able to demonstrate that larva density and colour morph variation were ecologically relevant: population density reduced dissolved organic carbon and increased primary production while mesocosms stocked with white morph larvae tended to have higher dissolved organic carbon and conductivity. Thus, while an adaptive significance of jelly coloration remains hypothetical, our results show that colour morphs differentially influence key ecosystem properties—dissolved organic carbon and conductivity.

一个新兴的共识表明，进化的种内变异可能具有重要的生态意义。然而，脊椎动物内部进化性状变异可以影响基本生态系统水平过程的证据仍然很少。在这项研究中，我们试图评估斑点蝾螈（ Ambystoma maculatum）进化变异对水生生态系统特性影响的潜力。斑点蝾螈在包裹卵的果冻颜色上表现出明显的多态性——一些雌性产生透明的果冻，而另一些则产生白色的果冻。尽管果冻颜色变化的功能意义在很大程度上仍然是推测性的，但繁殖力和幼虫形态差异的证据表明，颜色形态可能在生态效应的强度或特性上有所不同。在这里，我们通过中生态实验评估了斑点蝾螈颜色变形的频率变化对基本理化和生态系统特性（溶解有机碳、电导率、酸度和初级生产）的影响。通过操纵一系列幼虫密度的颜色变形频率，我们能够证明幼虫密度和颜色变形变化在生态上是相关的：种群密度减少了溶解的有机碳并增加了初级生产力，而饲养白色变形幼虫的中生态系统往往具有更高的溶解度有机碳和电导率。因此，虽然果冻颜色的适应性意义仍然是假设的，但我们的结果表明颜色形态对关键的生态系统特性（溶解的有机碳和电导率）有不同的影响。