Lighten up the dark: metazoan parasites as indicators for the ecology of Antarctic crocodile icefish (Channichthyidae) from the north-west Antarctic Peninsula

Abstract

Due to its remote and isolated location, Antarctica is home to a unique diversity of species. The harsh conditions have shaped a primarily highly adapted endemic fauna. This includes the notothenioid family Channichthyidae. Their exceptional physiological adaptations have made this family of icefish the focus of many studies. However, studies on their ecology, especially on their parasite fauna, are comparatively rare. Parasites, directly linked to the food chain, can function as biological indicators and provide valuable information on host ecology (e.g., trophic interactions) even in remote habitats with limited accessibility, such as the Southern Ocean. In the present study, channichthyid fish (Champsocephalus gunnari: n = 25, Chaenodraco wilsoni: n = 33, Neopagetopsis ionah: n = 3, Pagetopsis macropterus: n = 4, Pseudochaenichthys georgianus: n = 15) were collected off South Shetland Island, Elephant Island, and the tip of the Antarctic Peninsula (CCAML statistical subarea 48.1). The parasite fauna consisted of 14 genera and 15 species, belonging to the six taxonomic groups including Digenea (four species), Nematoda (four), Cestoda (two), Acanthocephala (one), Hirudinea (three), and Copepoda (one). The stomach contents were less diverse with only Crustacea (Euphausiacea, Amphipoda) recovered from all examined fishes. Overall, 15 new parasite-host records could be established, and possibly a undescribed genotype or even species might exist among the nematodes.

Helminth Diversity in Teleost Fishes from the Area of the Ukrainian Antarctic Station “Akademik Vernadsky”, Argentine Islands, West Antarctica

“…Th e blackfi n icefi sh were mainly infected with nematodes (66 % of the total helminth number), mostly with larval stages of anisakid nematodes of the genera Contracaecum and Pseudoterranova (see table 2). Various authors noted that Channichthyids, including blackfi n icefi sh, occupy a key position in the life cycles of anisakids in the Antarctic (Kock, 1992;Oğuz et al, 2012;Kuhn et al, 2018); their defi nitive hosts are marine mammals (Weddel seal, Antarctic fur seal, etc.). Predacious Ch.…”

Endoparasitic diversity from the Southern Ocean: is it really low in Antarctic fish?

“…The abundance of parasitic species in each host specimen was recorded and then averaged for each fish species sample. Databases were made using the new data collected in this study and complemented with 19 published articles about fish parasites in both zones of interest: the Antarctic and subantarctic systems (George-Nascimento & Arancibia, 1994; Walter et al ., 2002; Brickle et al ., 2005; González et al ., 2006; Laskowski et al ., 2007; Palm et al ., 2007; George-Nascimento et al ., 2009, 2011; Timi et al ., 2009; Vales et al ., 2011; Carballo et al ., 2012; Mackenzie et al ., 2013; Zdzitowiecki & Ozouf-Costaz, 2013; Santoro et al ., 2014; Flores et al ., 2016; Gordeev & Sokolov, 2016; Oliva et al ., 2016; Münster et al ., 2017; Kuhn et al ., 2018). A data matrix was made of 28 Antarctic and 18 subantarctic fish species, with different sample sizes ranging from two to 199 (table 1).…”

“…In a census of species from the Southern Ocean (De Broyer et al, 2014), the diversity of approximately 9000 different species of organismsincluding algae, invertebrates and vertebrates, and excluding parasiteswas considered. Nevertheless, approximately 270 parasite species have been recorded in 145 fish species, as shown in a checklist of parasites provided by Oğuz et al (2015), complemented with other sources (Kabata, 1965;Rokicki & Skorá, 1986;Sosiński & Janusz, 1986;Rokicki & Zdzitowiecki, 1991;Rokicki et al, 1992;Rohde et al, 1998;Walter et al, 2002;Kuhn et al, 2018). However, the number of species is insufficient to analyse biodiversity, which refers to the variability of life on Earth, and different methods have been widely discussed (e.g.…”

Productivity and Change in Fish and Squid in the Southern Ocean

“…Many Antarctic fish species are heavily parasitized, especially in their liver and guts, by various helminth worms as well as other groups such as acanthocephalans, hirudinea, and copepods (Oguz et al, 2015;Gordeev and Sokolov, 2017;Klimpel et al, 2017;Münster et al, 2017;Kuhn et al, 2018;Muñoz and Rebolledo, 2019). Fish parasite community assemblages help to elucidate the ecology of their hosts, their role in the food web, and in the life cycle and transfer of parasites across species in the Southern Ocean (Kloser et al, 1992;Palm et al, 2007;Klimpel et al, 2010;Mattiucci et al, 2015;Kuhn et al, 2018). While all affected fish show various levels of chronic inflammation at infection sites, only Antarctic icefishes, which tend to be the most infected group, showed a significantly negative correlation between parasitic load and condition index (Santoro et al, 2013).…”