Dust you shall eat: Complex considerations underlying a simple diet

Animals assimilate macronutrients and mineral nutrients in specific quantities and ratios to maximize fitness. To achieve this, animals must ingest different foods that contain the needed nutrients or facilitate the digestion of those nutrients. We explored how these multidimensional considerations affect the desert isopods (Hemilepistus reaumuri) food selection, using field and laboratory experiments. Wild isopods consumed 3-fold more macronutrient-poor biological soil crust (BSC) than plant litter.  Isopods tightly regulated macronutrient and calcium intake, but not phosphorus when eating the two natural foods and when artificial calcium and phosphorus sources substituted the BSC. Despite the equivalent calcium ingestion, isopods performed better when eating BSC compared to artificial foods. Isopods that consumed BSC sterilized by gamma-radiation ate more but grew slower than isopods that ate live BSC, implying that ingested microorganisms facilitate litter digestion. Our work highlig...

动物会按照特定的数量与比例同化宏量营养素（macronutrients）与矿物营养素（mineral nutrients），以最大化自身适合度（fitness）。为达成这一目标，动物必须摄取含有所需营养素或可辅助消化这些营养素的各类食物。本研究通过野外与实验室实验，探究了这类多维度的营养权衡如何影响沙漠等足类（isopods, Hemilepistus reaumuri）的食物选择。野生等足类对宏量营养素匮乏的生物土壤结皮（biological soil crust, BSC）的摄食量是植物凋落物（plant litter）的3倍。当摄食这两种天然食物，以及以人工钙、磷源替代生物土壤结皮时，等足类会严格调控宏量营养素与钙的摄入量，但并未对磷的摄入实施类似调控。尽管钙摄入量相当，但相较于人工配制食物，摄食生物土壤结皮的等足类生长表现更优。摄食经γ射线（gamma-radiation）灭菌处理的生物土壤结皮的等足类，其进食量更高，但生长速度却慢于摄食活生物土壤结皮的个体，这表明摄入的微生物可辅助凋落物的消化。本研究揭示了……