Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Guðbjörg Ósk Jónsdóttir (1), Laura-Marie von Elm (1), Finnur Ingimarsson (2), Samuel Tersigni (1), Anthony Curtat (1), Sigurður Sveinn Snorrason (1), Sarah Elizabeth Steele (1), Arnar Pálsson (1).
Starfsvettvangur / Affiliations: 1. Háskóli Íslands, 2. Náttúrufræðistofa Kópavogs
Kynnir / Presenter: Guðbjörg Ósk Jónsdóttir
The diversity of functional anatomy related to feeding has been influenced by natural selection. This diversity is particularly impressive in fishes and correlates with various ecological specializations. Differences between species originate as variation within species that selection can act on. The level of phenotypic parallelism and its ontogenetic roots are an active field of study. Arctic charr (Salvelinus alpinus) is a freshwater fish species known for its variation, allopatric and sympatric polymorphism, and most commonly diverges along a benthic-pelagic axis. In Iceland Arctic charr is found as anadromous (putative ancestral form) or non-anadromous (landlocked). In Lake Þingvallavatn, Iceland, four morphs of arctic charr coexist that differ in preferred prey, behaviour, habitat use, and external feeding morphology. We studied variation in functional phenotypic (i.e., bones shape and teeth characteristics) variation in nine upper and lower jaw bones of the four sympatric Þingvallavatn charr ecomorphs and compared them to anadromous charr (putative ancestral form). We have found clear phenotypic divergence between benthic and pelagic landlock morphs, with shape differing in four bones (dentary, articular-angular, premaxilla and maxilla), tooth number in 5 (dentary, maxilla, palatine, vomer and glossohyal) and tooth angle in one (maxilla). These results highlight the rapid functional evolution of specific anatomical structures, likely due to ecological opportunities.