Data from: Carotenoids and amphibians: effects on life history and susceptibility to the infectious pathogen, Batrachochytrium dendrobatidis

Carotenoids are considered beneficial nutrients because they provide increased immune capacity. Although carotenoid research has been conducted in many vertebrates, little research has been done in amphibians, a group that is experiencing global population declines from numerous causes, including disease. We raised two amphibian species through metamorphosis on three carotenoid diets to quantify the effects on life-history traits and post-metamorphic susceptibility to a fungal pathogen (Batrachochytrium dendrobatidis; Bd). Increased carotenoids had no effect on survival to metamorphosis in gray treefrogs (Hyla versicolor) but caused lower survival to metamorphosis in wood frogs [Lithobates sylvaticus (Rana sylvatica)]. Increased carotenoids caused both species to experience slower development and growth. When exposed to Bd after metamorphosis, wood frogs experienced high mortality, and the carotenoid diets had no mitigating effects. Gray treefrogs were less susceptible to Bd, which prevented an assessment of whether carotenoids could mitigate the effects of Bd. Moreover, carotenoids had no effect on pathogen load. As one of only a few studies examining the effects of carotenoids on amphibians and the first to examine potential interactions with Bd, our results suggest that carotenoids do not always serve amphibians in the many positive ways that have become the paradigm in other vertebrates.

类胡萝卜素（Carotenoids）被视为有益营养素，因其可提升机体免疫能力。尽管学界已在诸多脊椎动物中开展类胡萝卜素相关研究，但针对两栖动物的相关研究仍较为匮乏——两栖动物正因包括疾病在内的多种因素面临全球性种群衰退。本研究以三种类胡萝卜素日粮饲喂两种两栖动物直至完成变态发育，以量化类胡萝卜素对其生活史性状以及变态后真菌病原体（蛙壶菌，Batrachochytrium dendrobatidis，简称Bd）易感性的影响。结果显示，提高类胡萝卜素摄入量对灰树蛙（Hyla versicolor）的变态存活率无显著影响，但会降低林蛙（Lithobates sylvaticus，原分类为Rana sylvatica）的变态存活率；同时，两种物种的发育与生长速率均因类胡萝卜素水平提升而减缓。变态后暴露于蛙壶菌环境时，林蛙出现高死亡率，且类胡萝卜素日粮未表现出缓解效应；灰树蛙对蛙壶菌的易感性较低，因此无法评估类胡萝卜素是否能缓解蛙壶菌的感染危害。此外，类胡萝卜素对病原体载量无显著影响。作为少数探讨类胡萝卜素对两栖动物影响的研究之一，且是首个检验其与蛙壶菌潜在互作关系的研究，本研究结果表明，类胡萝卜素并非总能如在其他脊椎动物研究中确立的经典范式那般，对两栖动物发挥诸多有益作用。