Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster V94
Höfundar / Authors: Kalina H. Kapralova (1), Arnar Palsson (2), Sigurður S. Sanorrason (2), Sugrún Reynisdóttir (2), Jóhannes Guðbrandsson (3)
Starfsvettvangur / Affiliations: 1. Tilraunastöð Háskóla Íslands í meinafræði að Keldum , 2. Háskóli Íslands, (3) Hafrannsóknastofnun
Kynnir / Presenter: Kalina H. Kapralova
The Arctic charr in Lake Thingvallavatn, Iceland, is a classic example of parallel diversification along the benthic–limnetic axis. Following colonization after the last glaciation, the ancestral population diverged into four morphs: two benthic (small benthic, SB; large benthic, LB) and two limnetic (planktivorous, PL; piscivorous, PI), differing in morphology, diet, and habitat use. This system serves as a natural laboratory for studying the role of the immune system in adaptive divergence and speciation. We focused on the Major Histocompatibility Complex (MHC), key molecules in adaptive immunity, and tested whether variation in MHCIIα is linked to parasite load in Thingvallavatn charr. Four macroparasites were assessed: Diphyllobothrium sp., Diplostomum sp., parasitic nematodes, and Eubothrium salvelini. Parasite prevalence patterns matched previous findings, with Diplostomum sp. most common in SB and LB morphs, while Diphyllobothrium sp. and E. salvelini were more frequent in PL charr. Due to limited genetic variation in benthic morphs, MHCIIα effects on parasite load were tested only in the PL morph. No significant associations were found, either across genotypes or as quantitative variables. Our results therefore do not support parasite-mediated selection on MHCIIα allele frequencies in PL Arctic charr from Thingvallavatn.