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（parasitic helminths）类群的元素含量（碳、氮、磷百分比）及其化学计量比（碳氮比、碳磷比、氮磷比），旨在探究物种间的化学计量变异（stoichiometric variation）与分类学或功能性状的关联。我们采样了涵盖4个门的27个大型寄生虫（macroparasite）类群，这些类群寄生于美国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。 大型寄生虫的元素含量差异显著，氮百分比变异幅度达4.7倍，磷百分比变异幅度达4.6倍，氮磷比变异幅度达11.5倍。在所有受试物种中，寄生虫的磷百分比含量与体型呈负相关，碳磷比与体型呈正相关。在门级别以及单个物种种内，寄生虫磷含量与体型间均呈现相似的相关关系。 跨物种的磷元素异速生长关系（allometric scaling）支持生长速率假说（growth rate hypothesis），该假说预测体型更小的类群需要更多磷元素以维持相对更高的生长速率。寄生虫的生活史阶段与氮百分比及碳氮比相关：与活跃繁殖的寄生虫阶段相比，非繁殖阶段的氮百分比更低、碳氮比更高。 寄生虫的门、功能摄食类群（functional feeding group）以及营养级（trophic level）均无法解释物种间的元素含量变异。生物个体的生态化学计量学（stoichiometry）与生态功能密切相关，而大型寄生虫化学计量学的广泛变异，可能会塑造宿主-寄生虫营养动态的多样模式，以及寄生作用与养分循环间的可变关联。