Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster V71
Höfundar / Authors: Ásthildur Erlingsdóttir (1), Mark Freeman (2), Árni Kristmundsson (1)
Starfsvettvangur / Affiliations: 1. Institute for Experimental Pathology at Keldur, Iceland, 2. Ross University School of Medicine, Basseterre, St. Kitts
Kynnir / Presenter: Ásthildur Erlingsdóttir
Arctic charr (Salvelinus alpinus) is a widely distributed salmonid in Iceland, primarily inhabiting freshwater lakes and rivers, although some populations exhibit an anadromous life cycle. Iceland has emerged as the world's largest producer of farmed Arctic charr, with annual production around 6,000 tn since farming practices began in the early 1980s. Specimens from farmed populations, reared in local spring water, as well as wild Arctic charr and brown trout (Salmo trutta) from five Icelandic lakes, were collected for pathological examination. All sampled fish underwent histological examination, supplemented by molecular analyses and TEM in selected cases. Myxozoan parasites were detected in cardiac muscle tissues of all farmed Arctic charr examined, as well as in 4–30% of wild Arctic charr and in 2–7% of brown trout. Observations revealed polysporous plasmodia containing small spores (approx. 3.5 – 4.5 µm) with two polar capsules. PCR assays, specifically targeting multivalvulid myxosporeans, successfully amplified partial SSU rDNA sequences from infected heart muscle tissue. Sequence comparisons demonstrated over 98% similarity with known kudoid parasites infecting fish musculature. This marks the first documentation of a kudoid myxozoan infecting Arctic charr, notably expanding the known ecological range of this parasite group, which has predominantly been associated with marine environments. The discovery of this undescribed species in freshwater habitats provides valuab