An analysis of ectoparasite infestations in Champsocephalus gunnari at South Orkney Islands, Antarctica, was performed, which revealed the prevalence, mean abundance, and mean intensity of the two species of parasites collected. The parasites’ preference for parts of the infested host fish was also investigated. The host–parasite trophic relationship was further examined using stable carbon and nitrogen isotopic analysis. The results showed that Eubrachiella antarctica was more inclined to parasitize the fins of C. gunnari. The carbon isotope ratio (δ¹³C) of the host was negatively correlated with the values for carbon isotopic discrimination (Δδ¹³C) between host and E. antarctica. The relationship between E. antarctica and C. gunnar is considered “parasitic” because E. antarctica has a higher trophic level than that of host C. gunnari, while Trulliobdella capitis may be a carrier parasite of C. gunnari or show a “symbiotic” relationship with it. The ecological niche spaces of the three species do not overlap, indicating the existence of specific trophic niches in the marine food web.

对南极洲南奥克尼群岛的Champsocephalus Gunnari的体外寄生虫感染进行了分析，揭示了所收集的两种寄生虫的流行率、平均丰度和平均强度。还调查了寄生虫对受感染宿主鱼部分的偏好。使用稳定的碳和氮同位素分析进一步检查了宿主-寄生虫的营养关系。结果表明，南极真鳃藻更倾向于寄生于古纳里藻的鳍上。寄主的碳同位素比（δ ¹³ C）与寄主和南极洲E. antarctica之间的碳同位素辨别值（ Δδ ¹³ C）呈负相关。E. antarctica和C. Gunnar之间的关系被认为是“寄生”关系，因为E. antarctica的营养级高于宿主C. Gunnari的营养级，而Trulliobdella capitis可能是C. Gunnari的携带寄生虫或表现出“共生”关系与它的关系。三个物种的生态位空间不重叠，表明海洋食物网中存在特定的营养位。