Two manuscripts on Arctic charr were published in January. Guðbjörg Ósk Jónsdóttir, analyzed teeth variation in the sympatric morphs in Þingvallavatn, out in Evolutionary biology.
Jónsdóttir, G.Ó., Ingimarsson, F., Snorrason, S.S. et al. 2026 Variation of Tooth Traits in Ecologically Specialized and Sympatric Morphs. Evolutionary Biology. https://doi.org/10.1007/s11692-026-09665-2
Following up on work by Finnur Ingimarsson she describes allometry of teeth numbers, and differences by bones and morphs.
Influence of size and morph on number of teeth varied by bone. The scatterplots show individual tooth numbers (Y-axis) against size (ln(FL in cm) X-axis) for the four morphs and six bones; A dentary, B maxilla, C premaxilla, D palatine, E vomer and F glossohyal. Note the numbers for symmetric bones (A–D) are averages for the left and right bones. Each plot shows p values from glmmTMB for the effect of morph (M), body size (FL) and morph by body size (M × FL) on tooth number.
The other paper is by Han Xiao, also on the same morphs, in Molecular Ecology. He also included the mysterious fish from the downstream lake Úlfljótsvatn, and found some very cool differences in genetic composition.
, , , and . 2026. “ Gene Flow and Habitat Heterogeneity Shape Coexistence Dynamics of Arctic Charr Morphs in Connected Lakes.” Molecular Ecology 35, no. 2: e70225. https://doi.org/10.1111/mec.70225.