Analysis of changes in the infection patterns in black rockcod Notothenia coriiceps helminth community in West Antarctica over a six-year term

Abstract

Patterns of the rockcod Notothenia coriiceps infection with helminths were analysed to understand the dynamics of helminth communities in Antarctic fish and to test their stability over time. The study was performed using helminth samples (30,951 specimens in total) collected from 183 N. coriiceps in 2014–2015 and 2020–2021 in the vicinity of the Ukrainian Antarctic station (UAS) "Akademik Vernadsky", Galindez Island, Argentine Islands, West Antarctica. Overall, 25 helminth taxonomical categories (nine trematodes, four cestodes, five nematodes, and seven acanthocephalans) were distinguished and analysed. A direct comparison of the helminth taxonomic categories' prevalences and intensities showed that nine significantly changed their infection parameters during the six years between the samples. Seven of them (Pseudoterranova sp., Contracaecum sp., Ascarophis nototheniae, monolocular metacestodes, bilocular metacestodes, Metacanthocephalus rennicki, and Diphyllobothrium sp.) were found to have a significant impact on the differences between helminth infracommunities in 2014–2015 and 2020–2021. The range of changes in meteorological parameters (water and air temperature and water salinity) was not sufficient to significantly impact the helminth community’s patterns; most community patterns showed a stable trend and observed fluctuations were close to the steady trend. Slight but significant changes in the infection patterns observed in this study might have been caused by changes in the populations of intermediate, paratenic, and definitive hosts of helminths (marine invertebrates, mammals, and birds), which participate in helminth transmission in Antarctic ecosystems.