Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E63
Höfundar / Authors: Han Xiao (1), Arnar Pálsson (1), Sigurður S. Snorrason (1), Zophonías O. Jónsson (1)
Starfsvettvangur / Affiliations: (1) Institute of Life and Environmental Sciences, University of Iceland, Sæmundargata 2 102 Reykjavík, Iceland
Kynnir / Presenter: Han Xiao
Coexistence of phenotypically and ecologically distinct morphs has been widely reported in salmonids. We used landmark-based geometric morphometric methods to quantify the patterns of shape variation and shape covariation with size among four sympatric Arctic charr morphs in Lake Thingvallavatn, a unique hotspot of resource polymorphism. We found significant variation in both body shape and head shape among morphs, and also in allometric relationships. As expected, certain features of the head differed by morphotype, i.e. the large (LB) and small (SB) benthivorous charr, had more subterminal mouths than the limnetic morphotypes, i.e. planktivorous (PL) and piscivorous (PI) charr, whereas the relative size of the eye diminishes with body size as the small morphs (SB and PL) having larger eyes than the large morphs (LB and PI). We also uncovered variations in whole body shape among the morphs. For example, the bodies of the smaller morphs were more slender than those of larger morphs. Allometric relationships were tested using ANOVA with different model assumptions focusing on size, morphs, sexes, and interaction terms. We found significant shape covariation with size among morphs for both body and head shape. The effect of sex was not significant when taking morph into account. The data summarize the morphological differences between these morphs at a high resolution, which paves the way for a more thorough characterization of their functional differences and the ecological and genetic factors that influence them.