Abstract Understanding the influence of growth and development on the stoichiometry of organisms with complex lifecycles is necessary to understand the spatial and temporal extent of consumer-driven nutrient dynamics. This can be particularly challenging in temporally variable habitats, such as geographically isolated wetlands (GIW), which dry down seasonally. Larval anurans (tadpoles) are excellent model organisms for studies within the framework of ecological stoichiometry because they undergo major anatomical changes during metamorphosis that likely require a shift in body stoichiometric demands. To examine stoichiometry of larval anurans in GIWs, we measured larval Lithobates sphenocephalus tissue carbon (C), nitrogen (N), phosphorus (P) and calcium (Ca) content, excretion NH4-N, TDN and TDP, and egestion C, N and P across three developmental stage categories (no limbs, hind limbs only, and four limbs). We found that tissue P content increased significantly during later stages when bone development was occurring, which significantly reduced tissue C:P and N:P. Tissue C also increased across stages. Mass-specific excretion of TDN and N:P decreased across stages. Per capita NH4-N excretion rate had a positive relationship with body size, and per capita excretion N:P had a negative relationship with body size. Mass specific bulk egestion and C egestion varied across stages, as well as C:N and C:P, but we could not distinguish which stages were different from one another. Per capita egestion rates of N and P were positively correlated with body size, and both C:N and C:P were negatively related to body size. We found that development stage of larval anurans was an important indicator of tissue, excretion, and egestion stoichiometry and these differences may influence their functional role in aquatic ecosystems throughout their development.

中文翻译：

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天然湿地无尾幼虫发育的化学计量学

摘要 了解生长和发育对具有复杂生命周期的生物的化学计量的影响对于了解消费者驱动的营养动态的空间和时间范围是必要的。这在时间可变的栖息地中尤其具有挑战性，例如季节性干燥的地理上孤立的湿地 (GIW)。无尾幼虫（蝌蚪）是生态化学计量学框架内研究的优秀模式生物，因为它们在变态过程中经历了重大的解剖学变化，这可能需要改变身体化学计量学的需求。为了检查 GIW 中无尾幼虫的化学计量，我们测量了幼虫 Lithobates sphenocephalus 组织碳 (C)、氮 (N)、磷 (P) 和钙 (Ca) 的含量，排泄 NH4-N、TDN 和 TDP，以及排泄 C，N 和 P 跨越三个发育阶段类别（没有四肢、只有后肢和四肢）。我们发现组织 P 含量在骨发育后期显着增加，这显着降低了组织 C:P 和 N:P。组织 C 也在各个阶段增加。TDN 和 N:P 的质量特异性排泄在各个阶段减少。人均NH4-N排泄率与体型呈正相关，人均N:P与体型呈负相关。质量特定的散装消化和 C 消化在不同阶段以及 C:N 和 C:P 之间变化，但我们无法区分哪些阶段彼此不同。N和P的人均摄入率与体型呈正相关，C:N和C:P均与体型呈负相关。