Large Pelagics Research Center, School for the Environment, University of Massachusetts Boston, Gloucester, MA, USA.
College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA, USA.
J Fish Dis. 2020 Mar;43(3):327-335. doi: 10.1111/jfd.13129. Epub 2020 Jan 26.
Ectoparasitic flatworms of Nasicola (Monogenoidea: Capsalidae), which infect nasal epithelium of true tunas (Thunnus spp.), are not well studied, nor have their impacts on the host's olfactory organ been evaluated. Infections of Nasicola hogansi on Atlantic bluefin tuna, Thunnus thynnus, were investigated with emphasis on the relationship between infection prevalence, abundance and mean intensity with bluefin tuna size, sex, body condition and capture month, as well as histopathological effects. Commercially caught Atlantic bluefin tuna (n = 161, 185-305 cm curved fork length) from the Gulf of Maine were sampled during June through August 2009 for infections by N. hogansi. A total of 247 specimens of N. hogansi were collected, with a prevalence of 45.3%, mean abundance of 1.57 (CI: 1.21-2.03) and mean intensity of 3.45 (CI: 2.91-4.22). Neither fish sex nor landing month had a significant effect on parasite parameters. Larger and better-conditioned Atlantic bluefin tuna had a higher mean intensity of infection. Pathology associated with infection by N. hogansi included extensive necrosis, sloughing of the nasal epithelium and associated inflammation of underlying connective tissues. Further epidemiological and pathological study of this host-parasite system is warranted since impaired olfaction, if present, could adversely affect spawning and migration of this top ocean predator.
寄生在真鲹（鲭科：Capsalidae）鼻上皮的扁形外寄生虫 Nasicola（单殖亚纲：Capsalidae）研究较少，其对宿主嗅觉器官的影响也尚未评估。本研究重点调查了 Nasicola hogansi 对大西洋蓝鳍金枪鱼（Thunnus thynnus）的感染情况，分析了感染率、丰度和平均强度与蓝鳍金枪鱼大小、性别、身体状况和捕捞月份之间的关系，以及组织病理学影响。2009 年 6 月至 8 月，在缅因湾商业捕捞的大西洋蓝鳍金枪鱼（n = 161，弯曲叉长 185-305 厘米）样本中检测到 N. hogansi 感染。共采集到 247 个 N. hogansi 标本，感染率为 45.3%，平均丰度为 1.57（置信区间：1.21-2.03），平均强度为 3.45（置信区间：2.91-4.22）。鱼类性别和捕捞月份对寄生虫参数均无显著影响。体型较大、身体状况较好的大西洋蓝鳍金枪鱼感染强度更高。与 N. hogansi 感染相关的病理学包括广泛的坏死、鼻上皮脱落和相关的下结缔组织炎症。由于受损的嗅觉，如果存在，可能会对这种顶级海洋捕食者的繁殖和洄游产生不利影响，因此有必要对这种宿主-寄生虫系统进行进一步的流行病学和病理学研究。
