Department of Evolutionary Ecology, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain.
Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
Mol Ecol. 2019 Jan;28(2):203-218. doi: 10.1111/mec.14581. Epub 2018 May 3.
Parasites and other symbionts are crucial components of ecosystems, regulating host populations and supporting food webs. However, most symbiont systems, especially those involving commensals and mutualists, are relatively poorly understood. In this study, we have investigated the nature of the symbiotic relationship between birds and their most abundant and diverse ectosymbionts: the vane-dwelling feather mites. For this purpose, we studied the diet of feather mites using two complementary methods. First, we used light microscopy to examine the gut contents of 1,300 individual feather mites representing 100 mite genera (18 families) from 190 bird species belonging to 72 families and 19 orders. Second, we used high-throughput sequencing (HTS) and DNA metabarcoding to determine gut contents from 1,833 individual mites of 18 species inhabiting 18 bird species. Results showed fungi and potentially bacteria as the main food resources for feather mites (apart from potential bird uropygial gland oil). Diatoms and plant matter appeared as rare food resources for feather mites. Importantly, we did not find any evidence of feather mites feeding upon bird resources (e.g., blood, skin) other than potentially uropygial gland oil. In addition, we found a high prevalence of both keratinophilic and pathogenic fungal taxa in the feather mite species examined. Altogether, our results shed light on the long-standing question of the nature of the relationship between birds and their vane-dwelling feather mites, supporting previous evidence for a commensalistic-mutualistic role of feather mites, which are revealed as likely fungivore-microbivore-detritivore symbionts of bird feathers.
寄生虫和其他共生体是生态系统的关键组成部分，它们调节着宿主种群并支持着食物网。然而，大多数共生体系统，特别是那些涉及共生和互利共生的系统，相对来说理解得还不够充分。在这项研究中，我们研究了鸟类与其最丰富和最多样化的外共生体——羽片寄居的羽螨之间的共生关系的本质。为此，我们使用两种互补的方法研究了羽螨的饮食。首先，我们使用光学显微镜检查了代表 100 个螨属（18 科）的 1300 个羽螨个体和 190 种鸟类的肠道内容物，这些鸟类属于 72 科和 19 目。其次，我们使用高通量测序（HTS）和 DNA 代谢组学从栖息在 18 种鸟类的 18 种羽螨的 1833 个个体中确定了肠道内容物。结果表明真菌和潜在细菌是羽螨的主要食物来源（除了潜在的鸟类尾脂腺油）。硅藻和植物物质似乎是羽螨的稀有食物来源。重要的是，我们没有发现羽螨除了潜在的尾脂腺油之外，以鸟类资源（如血液、皮肤）为食的任何证据。此外，我们发现在所检查的羽螨物种中，角质亲和性和致病性真菌类群的患病率很高。总的来说，我们的研究结果揭示了鸟类与其羽片寄居的羽螨之间关系的本质这一长期存在的问题，支持了羽螨具有共生互利作用的先前证据，羽螨是鸟类羽毛的可能的真菌食性-微生物食性-碎屑食性共生体。
