Seasonal dietary shifts enhance parasite transmission to lake salmonids during ice cover
Seasonal dietary shifts enhance parasite transmission to lake salmonids during ice cover
复制标题
季节性饮食变化增强冰盖期间寄生虫向鲑鱼湖的传播
作者：
S. Prati;E. Henriksen;R. Knudsen;P. Amundsen
亚北极湖泊系统的非生物和生物因子在季节之间的变化往往是深刻的，可能影响寄生虫在年循环中的群落结构和种群动态。然而，很少有冬季研究存在，鱼类宿主和它们的寄生虫之间的相互作用通常局限于局限于夏季的快照研究，而在冰雪覆盖期间，宿主-寄生虫的动态很少被探索。目前的研究解决了肠道寄生虫感染的季节性模式及其与挪威北部亚北极湖泊Takvatn湖的同域生活北极鲑（Salvelinus alpinus）和褐鳟（Salmo trutta）饮食的关系。在2017年6月至2018年5月期间，总共从沿海栖息地取样了354条北极鲑和203条褐鳟。鉴定并量化了6个营养传播的肠道寄生虫类群，并将它们的季节变化与鱼的胃和肠的饮食信息进行了对比。冬季被证明是寄生虫的重要传播窗口，北极炭中片足类传播的寄生虫和褐鳟中通过鱼类猎物传播的寄生虫的流行率和强度都有所增加。在北极地区，寄生虫感染的季节性模式主要是由对片脚类动物的饮食的时间变化引起的，而在褐鳟中，宿主体型和对鱼类猎物的利用是主要驱动因素。寄生虫群落结构的整体动态主要反映了寄主鱼类的季节性饮食变化。
Abstract Changes in abiotic and biotic factors between seasons in subarctic lake systems are often profound, potentially affecting the community structure and population dynamics of parasites over the annual cycle. However, few winter studies exist and interactions between fish hosts and their parasites are typically confined to snapshot studies restricted to the summer season whereas host‐parasite dynamics during the ice‐covered period rarely have been explored. The present study addresses seasonal patterns in the infections of intestinal parasites and their association with the diet of sympatric living Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in Lake Takvatn, a subarctic lake in northern Norway. In total, 354 Arctic charr and 203 brown trout were sampled from the littoral habitat between June 2017 and May 2018. Six trophically transmitted intestinal parasite taxa were identified and quantified, and their seasonal variations were contrasted with dietary information from both stomachs and intestines of the fish. The winter period proved to be an important transmission window for parasites, with increased prevalence and intensity of amphipod‐transmitted parasites in Arctic charr and parasites transmitted through fish prey in brown trout. In Arctic charr, seasonal patterns in parasite infections resulted mainly from temporal changes in diet toward amphipods, whereas host body size and the utilization of fish prey were the main drivers in brown trout. The overall dynamics in the community structure of parasites chiefly mirrored the seasonal dietary shifts of their fish hosts.