Abstract

Parasites play significant roles in the function of ecosystems and can make up a large proportion of overall biomass. Yet, fundamental aspects of their ecology are often understudied relative to other organisms. Gnathiid isopods are the primary ectoparasites of fishes in coral reef ecosystems. While some studies have investigated their host-detection capabilities, the means by which they seek hosts are largely unknown. Gnathiids are benthic and live on the bottom, and all collection efforts involving live hosts have thus far involved traps set at or near the reef substrate. We investigated the distance gnathiids will travel vertically in the water column to attach to a fish host. The majority of gnathiids collected were at or less than 1 m above the reef substrate, and gnathiids were collected in serially diminishing numbers at 2 and 3 m above it. No gnathiids were collected from any fish hosts set more than 3.5 m above the reef substrate. Results suggest that gnathiids will actively seek host fishes in situ and will travel further from their benthic habitat than previously known. By swimming into the water column, gnathiids can exploit larger, highly-mobile fishes, which can serve as a major source of dispersal.

中文翻译：

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加勒比珊瑚礁鱼类寄生虫类蠕足类动物（伊索波达：:科）的寄主侵染的垂直极限

摘要

寄生虫在生态系统的功能中起着重要作用，并且可以构成整个生物量的很大一部分。然而，相对于其他生物而言，其生态学的基本方面常常被研究不足。食蚁兽等足动物是珊瑚礁生态系统中鱼类的主要外寄生物。尽管一些研究调查了其宿主检测能力，但寻找宿主的方法很大程度上未知。棘突类动物是底栖动物，生活在底部，到目前为止，所有涉及活宿主的收集工作都涉及在礁底物处或附近设置的陷阱。我们调查了鱼在水柱中垂直移动到附着在鱼宿主上的距离。收集的大部分咬虫类动物位于礁底物上方或小于1 m处，而收集的咬虫类动物在其上方2和3 m处数量依次减少。在礁底以上3.5 m以上的任何鱼类寄主中均未收集到类固醇。结果表明，鱼将积极寻找寄主鱼原位，并将比以前已知的更远离底栖生境。通过游入水柱，鱼可以利用较大的，流动性强的鱼类，而鱼类可以作为主要的扩散来源。