Abstract:
Anadromous river herring have declined in many parts of their range, leading to fisheries management efforts to help repopulate this species by improving connectivity of rivers and restoring populations by fish transfers. With data lacking on parasites in these species, this study sought to better understand myxozoans across various life stages and habitats in river herring populations in New Jersey, USA. We compared fish from riverine habitats during early-life growth and adults returning to spawn, marine-phase fish, and landlocked Alewife populations. Three myxozoan species were identified in young-of-the-year (YOY) anadromous river herring, including Kudoa clupeidae in the skeletal musculature, Myxobolus mauriensis in the rib cartilage, and an uncharacterized coelozoic myxozoan within the lumen of mesonephric tubules. In YOY river herring, Blueback Herring were 2 times more likely to be infected by K. clupeidae than Alewife (p = 0.019) and in the Maurice River, fish were 4 times more likely to be infected with M. mauriensis than fish from Great Egg Harbor River (p = 0.000) and 11 times more likely than the Delaware River (p = 0.001). Spawning adult river herring were infected with a previously undescribed myxozoan parasite infecting the kidney. Sequencing the 18S rDNA indicated this species is closely related to Ortholinea species. Myxobolus mauriensis and the Ortholinea-like species were absent from marine-phase river herring indicating that infections were linked to river environments occurring during early-life growth and spawning, respectively. No myxozoans were present in landlocked Alewife, showing that similar infections occurring in rivers were absent in lake environments in the region.
摘要:
在其范围的许多地方,对流河鲱鱼已经减少,通过改善河流的连通性和通过鱼类转移来恢复种群,从而导致渔业管理努力帮助该物种重新繁殖。由于这些物种缺乏寄生虫的数据,这项研究旨在更好地了解新泽西州鲱鱼种群中各个生命阶段和栖息地的粘液动物,美国。我们比较了早期生长过程中来自河流栖息地的鱼类和返回产卵的成虫,海洋阶段的鱼,和内陆Alewife人口。在年幼年(YOY)的无河流鲱鱼中发现了三种粘液动物,包括骨骼肌中的Kudoaclupeidae,肋软骨中的Myxobolusmauriensis,和中肾小管内腔内的未表征的新生代粘液动物。在yoy河鲱鱼,蓝背鲱鱼被K.clupeidae感染的可能性是Alewife的2倍(p=0.019),在莫里斯河中,鱼感染M.mauriensis的可能性是大蛋港河的鱼的4倍(p=0.000),是特拉华河的11倍(p=0.001)。产卵的成年河鲱鱼感染了先前未描述的感染肾脏的粘液虫寄生虫。对18SrDNA进行测序表明,该物种与Ortholinea物种密切相关。海洋阶段的鲱鱼中不存在Myxobolusmauriensis和Ortholinea样物种,这表明感染与生命早期生长和产卵期间发生的河流环境有关,分别。内陆阿利瓦夫没有粘虫,表明在该地区的湖泊环境中没有在河流中发生类似的感染。