南极磷虾寄生虫多样性与生态学研究进展:簇虫、线虫和纤毛虫

南极磷虾广泛栖息于环南极水域, 其生物量极为丰富, 为世界上最大的动物蛋白质来源之一。以磷虾(如三刺磷虾 Euphausia. triacantha、瓦氏磷虾 E. vallentini、长额樱磷虾 Thysanoessa macrura 以及南极大磷虾 Euphausia superba)为中间宿主或终末宿主的寄生虫广泛存在于南大洋食物网的不同营养级生物中, 是形成南极生物多样性的重要组成部分。为了充分了解南极磷虾寄生虫的类型、生态特性以及感染机制等, 本文对其种类多样性、生命周期、寄生部位、影响机制、宿主多样性等方面进行系统总结与分析。结果显示, 南极磷虾寄生虫多样性主要集中在同种磷虾感染多种寄生虫以及同种寄生虫感染多种磷虾等; 磷虾体内寄生虫的传播途径基本上为沿食物网传播; 体内寄生虫对宿主的危害大于体外寄生虫; 宿主体长越长, 感染寄生虫越多等。针对今后的研究, 建议重点开展感染机制、发现新寄生虫或宿主等方面的工作, 而利用寄生虫作为生态指示物种开展气候变化对南极的影响将有较好的研究前景。

Diversity and ecology of gregarine, nematode, and ciliate parasites in Euphausiids in the Antarctic-A review

Krill widely inhabit the circumpolar waters at very high biomasses and comprise one of the largest animal protein sources in the world. Parasites that use Euphausiid krill species (such as Euphausia superba, E. vallentini, E. triacantha, and Thysanoessa macrura) as intermediate or terminal hosts widely exist in animals at different trophic levels in the food web of the Southern Ocean and comprise an important part of the Antarctic biodiversity. In order to fully understand the biological features, ecological characteristics, and infection mechanisms of parasites of krill, this review systematically summarizes the species compositions, life cycles, parasitic tissues, and infection mechanisms of the dominant parasite species (gregarine, nematode, and ciliate) of Euphausiids and the diversity of host species. The results indicate that parasite diversity is mainly concentrated in the same kind of krill species, as krill species are often infected by multiple species of parasites, and the same parasite species can infect multiple species of krill. The endoparasites of krill can easily spread through the food web, and the damage caused to hosts is greater for endoparasites than that for ectoparasites. Furthermore, the number of parasites increases with the increasing size of infected hosts. We recommended that future studies focus on the infection mechanism of parasites and the discovery of new parasites or hosts. We also believe future studies could use parasites as ecological indicators to better understand the impact of climate change on the Antarctic ecosystem.