Data from: Allometric and trait-based patterns in parasite stoichiometry

We measured the elemental content (%C, N, and P) and ratios (C:N, C:P, N:P) of a diverse assemblage of parasitic helminths to ask whether taxonomy or traits were related to stoichiometric variation among species. We sampled 27 macroparasite taxa, spanning 4 phyla, infecting vertebrate and invertebrate hosts from freshwater ecosystems in New Jersey. Macroparasites varied widely in elemental content, exhibiting 4.7-fold variation in %N, 4.6-fold variation in %P, and 11.5-fold variation in N:P. Across all species, parasite %P scaled negatively and C:P scaled positively with body size. Similar relationships between parasite P content and body size occurred at the phylum level and within individual species. The allometric scaling of P across species supports the growth rate hypothesis, which predicts that smaller taxa require more P to support relatively higher growth rates. Life cycle stage was related to %N and C:N, with non-reproductive parasite stages lower in %N and higher in C:N than actively reproducing parasites. Parasite phylum, functional feeding group, and trophic level did not explain elemental variation among species. Organismal stoichiometry is linked to ecological function, and wide variation in macroparasite stoichiometry likely generates diverse patterns in host-parasite nutrient dynamics and variable relationships between parasitism and nutrient cycling.本研究测定了多样寄生蠕虫类群的元素含量（%C、%N和%P）及化学计量比（C:N、C:P、N:P），旨在探究物种间的化学计量变异与分类学特征或功能性状的关联。本研究共采样覆盖4个动物门的27个大型寄生生物（macroparasite）类群，这些类群寄生于新泽西州淡水生态系统中的脊椎动物与无脊椎动物宿主体内。大型寄生生物的元素含量差异显著，其中%N的变异幅度达4.7倍，%P达4.6倍，N:P比达11.5倍。在所有受试物种中，寄生生物的%P与个体体型呈负相关，而C:P比则与体型呈正相关。在门分类水平以及单个物种类群内部，同样存在寄生生物磷含量与个体体型的上述关联模式。跨物种的磷元素异速标度（allometric scaling）特征支持生长速率假说（Growth Rate Hypothesis）：该假说指出，体型更小的类群需要更多的磷元素以支撑相对更高的生长速率。寄生生物的生命周期阶段与%N及C:N比显著相关：非繁殖阶段的寄生生物%N更低，C:N比则高于处于活跃繁殖期的寄生个体。寄生生物所属的门、功能摄食类群以及营养级，均无法解释物种间的元素含量变异。生物个体的化学计量学与生态功能紧密关联，大型寄生生物化学计量学的广泛变异，可能会塑造宿主-寄生生物营养动态的多样模式，并改变寄生作用与养分循环之间的可变关联。