Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017

Erindi/veggspjald / Talk/poster E60

Relationships between dietary and morphological differences between individuals within populations of small benthic Arctic charr in Iceland

Höfundar / Authors: Camille Leblanc, Skúli skúlason

Starfsvettvangur / Affiliations: Háskólinn á Hólum

Kynnir / Presenter: Bjarni K. Kristjánsson

Northern freshwater fishes show an unusual intraspecific phenotypic diversity, with two or more sympatric morphs or even species, within the same area. This polymorphism is commonly seen in structures and/or behaviour for exploiting resources (i.e.resource polymorphism) and can give rise to discrete morphs or even new species. In Iceland small benthic Arctic charr (Salvelinus alpinus) are good examples of parallel evolution. Populations of small benthic Arctic charr seem to be adapting in a similar way to lava rock and groundwater habitat found along the volcanic active zone, indicating the importance of natural selection for the evolution of these populations.
Studies on early stages of intraspecific diversity are important for the evolution of diversification and speciation. Early stages of diversification can be seen in individual specialization, where individuals consume only a portion of the diet of the population as a whole, and how such specialization is related to phenotypic diversity within populations. Here we study the strength of the relationship between morphological and dietary distances among individuals in eighteen populations of Icelandic small benthic charr.
In all the populations studied there was a clear relationship between morphological and dietary distances, indicating that fish that had similar morphology were at the same time consuming similar diet. Our findings show a systematic variation at early stages of diversification in a highly specialized morph. This study shows the value of systematic comparisons among populations and how such fine tuned studies can advance our understanding of processes of evolution in relation to local ecology.