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）被视为有益营养物质，因其可增强免疫能力。尽管已有诸多针对脊椎动物的类胡萝卜素研究，但针对两栖动物的相关研究却寥寥无几——而两栖动物正因包括病害在内的多重因素正经历全球性种群衰退。本研究通过三种类胡萝卜素饮食方案，将两种两栖动物培育至变态发育阶段，以量化其对物种生活史特征以及变态后真菌病原体蛙壶菌（Batrachochytrium dendrobatidis，简称Bd）易感性的影响。提升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，曾用名Rana sylvatica）的变态存活率。摄入更高剂量的类胡萝卜素会使两个物种的发育与生长速率均放缓。变态完成后接触蛙壶菌时，林蛙出现高死亡率，而类胡萝卜素饮食未表现出缓解效应。灰树蛙对蛙壶菌的易感性更低，因此无法评估类胡萝卜素是否能缓解其感染后的影响。此外，类胡萝卜素对病原体载量无显著影响。本研究是少数探讨类胡萝卜素对两栖动物影响的研究之一，也是首个考察其与蛙壶菌潜在互作的研究。结果表明，类胡萝卜素并非总能如在其他脊椎动物中那样，为两栖动物带来诸多公认的益处。