Abstract Aquatic invasive species (AIS) are important vectors for the introduction of novel pathogens which can, in turn, become drivers of rapid ecological and evolutionary change, compromising the persistence of native species. Conservation strategies rely on accurate information regarding presence and distribution of AIS and their associated pathogens to prevent or mitigate negative impacts, such as predation, displacement or competition with native species for food, space or breeding sites. Environmental DNA is increasingly used as a conservation tool for early detection and monitoring of AIS. We used a novel eDNA high-resolution melt curve (HRM) approach to simultaneously detect the UK endangered native crayfish (Austropotamobius pallipes), the highly invasive signal crayfish (Pacifastacus leniusculus) and their dominant pathogen, Aphanomyces astaci (causative agent of crayfish plague). We validated the approach using laboratory and field samples in areas with known presence or absence of both crayfish species as well as the pathogen, prior to the monitoring of areas where their presence was unknown. We identified the presence of infected signal crayfish further upstream than previously detected in an area where previous intensive eradication attempts had taken place, and the coexistence of both species in plague free catchments. We also detected the endangered native crayfish in an area where trapping had failed. With this method, we could estimate the distribution of native and invasive crayfish and their infection status in a rapid, cost effective and highly sensitive way, providing essential information for the development of conservation strategies in catchments with populations of endangered native crayfish.

中文翻译：

---

利用环境DNA同时检测入侵信号小龙虾、濒危白爪小龙虾和小龙虾瘟疫病原体

摘要 水生入侵物种 (AIS) 是引入新病原体的重要载体，这些病原体反过来又会成为快速生态和进化变化的驱动因素，从而危及本地物种的持久性。保护战略依赖于关于 AIS 及其相关病原体的存在和分布的准确信息，以防止或减轻负面影响，例如捕食、流离失所或与本地物种争夺食物、空间或繁殖场所。环境 DNA 越来越多地用作早期检测和监测 AIS 的保护工具。我们使用了一种新的 eDNA 高分辨率熔解曲线 (HRM) 方法同时检测了英国濒临灭绝的本地小龙虾 (Austropotamobius pallipes)、高侵袭性信号小龙虾 (Pacifastacus leniusculus) 及其主要病原体，Aphanomyces astaci（小龙虾瘟疫的病原体）。我们使用实验室和现场样本在已知存在或不存在小龙虾物种和病原体的区域验证了该方法，然后再对未知区域进行监测。我们发现受感染信号小龙虾的存在比先前在之前进行了密集根除尝试的地区更上游，并且这两种物种在无鼠疫集水区共存。我们还在诱捕失败的地区发现了濒临灭绝的本地小龙虾。使用这种方法，我们可以快速、经济高效且高度灵敏地估计本地和入侵小龙虾的分布及其感染状态，