Host specificity and diversity of larval digeneans in freshwater fish

淡水鱼双殖期幼虫的寄主特异性和多样性

• 批准号: 6979-2012
• 负责人: McLaughlin, Daniel
• 金额: $ 1.53万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=544391
• 关键词: Host; specificity; diversity; larval; digeneans

SUMMARY: Larval parasites form a major component of the parasite community of fish that remains unstudied due to the inability to distinguish between species. Hence, these parasites are typically treated as generalists capable of infecting many unrelated fish species and the role of larvae species in structuring parasite communities remains largely unknown. Our DNA-based field studies demonstrated that the larval parasite community is actually highly diverse and that most species are host specific although there are some generalists. Although field studies are essential for revealing the natural distribution of parasite species within host communities, the mechanisms underlying these distributions can only be elucidated experimentally. We will use a combination of DNA-based field and laboratory studies to determine the natural distribution of larval parasites in four unstudied families of fish from the St. Lawrence River. We will then test, through experimental infections, (1) the relative importance of contact (host ecology) and compatibility factors (host phylogeny) in determining the host range of larval species that have host-specific distributions in nature and (2) whether the performance of Diplostomum spp., which occur in many distantly related fish species in nature, varies in different host species and whether this variation can be attributed to contact or compatibility factors. Generalist Diplostomum spp. are restricted to a single tissue, the lens of the eye, and mixed infections are common Hence, interactions between species are possible. We will investigate the performance of two species of Diplostomum, experimentally in fish hosts (1) exposed to simultaneous infections of two species and (2) in sequential infections sevearl weeks apart. Together, these studies will provide exhaustive data with unequalled taxonomic resolution on the distribution larval parasites in fish in the St. Lawrence River, and will elucidate the importance of ecological and phylogenetic factors in determining the presence, absence and abundance of particular species in different fish hosts.

摘要：由于不能区分物种，幼虫构成了鱼类寄生虫群落的主要组成部分，至今仍未得到研究。因此，这些寄生虫通常被视为多面手，能够感染许多无关的鱼类物种，而幼虫物种在构建寄生虫群落中的作用在很大程度上仍不清楚。我们基于DNA的实地研究表明，幼虫群落实际上是高度多样化的，尽管也有一些通才，但大多数物种都是宿主特有的。虽然实地研究对于揭示寄主群落内寄生虫物种的自然分布是必不可少的，但这些分布背后的机制只能通过实验来阐明。我们将使用基于DNA的现场和实验室研究相结合的方法来确定来自圣劳伦斯河的四个未被研究的鱼类家族中幼虫的自然分布。然后，我们将通过实验感染测试(1)接触(宿主生态学)和兼容性因素(宿主系统发育)在确定在自然界中具有宿主特有分布的幼虫物种的宿主范围方面的相对重要性，以及(2)在自然界中许多远亲鱼类物种中出现的双口线虫的表现是否在不同宿主物种中有所不同，以及这种差异是否可归因于接触或兼容性因素。多面手双口藻属仅限于单个组织，眼睛的晶状体，混合感染很常见，因此，物种之间的相互作用是可能的。我们将通过实验研究两种双口线虫在鱼类宿主(1)同时感染两种双口线虫和(2)在相隔几周的连续感染中的表现。总之，这些研究将为圣劳伦斯河鱼类幼虫寄生虫的分布提供无与伦比的分类分辨率的详尽数据，并将阐明生态和系统发育因素在确定特定物种在不同鱼类宿主中的存在、缺失和丰度方面的重要性。