Assessing the Level of Risk of Introduction and Spread of Exotic Oomycete Species via Ornamental Fish Imports to Wild Fish Populations and Fish Popula

每年有数百万观赏鱼被进口到英国，可能携带大量的病原体。据Cefas FHI所知，从东南亚进口的一些产品携带病毒病原体。人们对进口的卵菌病原体知之甚少。在水产养殖中，两种卵菌已经独立出现，成为非常成功的鳍鱼病原体。在英国和其他地方，寄生病是导致鲑鱼高死亡率的原因。入侵隐菌是世界动物卫生组织（OIE）法定传染病兽疫性溃疡综合征（EUS）的罪魁，该疾病正在地理上蔓延，并已在亚洲和非洲确立。对这两种病原体敏感的鱼类种类范围很大，而且重叠但不完全相同。这两种病原体不仅影响养殖鱼类，也影响自然种群。本博士项目的目的是通过检测近期进口的样品来评估此类进口的风险水平。将对野生鱼类种群和渔场的样本进行测试，以评估这些病原体在自然环境中的存在。系统发育分析将用于将进口菌株与在野外发现的菌株联系起来。这将有助于评估进口卵菌病原体对渔场和野外鱼类种群的潜在威胁。

Millions of ornamental fish are being imported every year into the UK, potentially carrying a huge range of pathogens. It is known to the Cefas FHI that some of the imports from south east Asia are imported carrying viral pathogens. Less is known about the Oomycete pathogens that are being imported. Two species of oomycetes have independently emerged as highly successful pathogens of finfish in aquaculture. Saprolegnia parasitica is responsible for high levels of mortality in salmon in the UK and elsewhere. Aphanomyces invadans is responsible for the OIE notifiable disease epizootic ulcerative syndrome (EUS), which is spreading geographically and is already well established in Asia and Africa. The ranges of fish species susceptible to the two pathogens are large and overlapping but not identical. Both pathogens not only affect farmed fish but also natural populations.The purpose of this PhD project is to assess the level of risk from such imports by testing samples from recent imports. Samples from wild fish populations and fisheries will be tested to assess the presence of these pathogens in the natural environment. Phylogenetic analyses will be applied to relate imported strains to those found in the wild. This will allow to assess the potential threat from imported Oomycete pathogens for fish populations in fisheries and the wild.