Champsocephalus gunnari

Kuzmina, T. A., Salganskiy, O. O., Vishnyakova, K. O., Ivanchikova, J., Lisitsyna, O. I., Korol, E. M. & Kuzmin, Yu. I., 2022, Helminth Diversity In Teleost Fishes From The South Orkney Islands Region, West Antarctica, Zoodiversity 56 (2), pp. 135-152 : 141-142

Champsocephalus gunnari

In the mackerel icefish, only 8 helminth species were recorded (from 1 to 6 species per host): 1 species of trematodes, 4 species of cestodes and 3 species of nematodes (table 3). Species richness estimated using Chao1, jackknife, and bootstrap methods equalled 8 species. The diversity indices were 1.32 (Shannon), 0.67 (Simpson), and 0.63 (Pielou’s evenness).

Only two helminth species, a digenean trematode N. georgiensis and a nematode A. nototheniae parasitized C. gunnari on the adult stage; all other parasites were found on immature stages. Therefore, C. gunnari is considered to be a definitive host for 2 out of 8 helminth species recorded. Cestodes predominated in the helminth community of mackerel icefish; together they comprised 91.16 % of the total helminth number ( fig. 1 ).

According to the prevalence (table 3), helminths of C. gunnari might be separated into two groups. Four species, namely Diphyllobothrium sp. , bilocular and trilocular metacestodes, and the trematode N. georgiensis reached the prevalence of 79–94 %; thus, these species predominated in the helminth community. Other species occurred rarely, with the highest prevalence of 35.3 % in Contracaecum sp.

Figures

Fig. 1. Proportion (%) of four parasite taxa in three fish species from the South Orkney Islands area, West Antarctica.