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Divergent, genetically based feeding behaviour of two sympatric Arctic charr, Salvelinus alpinus (L.), morphs
Author(s) -
Klemetsen A.,
Knudsen R.,
Primicerio R.,
Amundsen P.A.
Publication year - 2006
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2006.00128.x
Subject(s) - salvelinus , profundal zone , biology , ecology , ecological niche , sympatric speciation , littoral zone , predation , arctic , sympatry , stickleback , habitat , fishery , trout , fish <actinopterygii>
– Arctic charr, Salvelinus alpinus (L.), is one of the several northern fishes that show resource polymorphisms in postglacial lakes. Two reproductively isolated morphs of Arctic charr coexist in distinct ecological niches in the subarctic lake Fjellfrøsvatn, North Norway. Offspring of the two morphs (termed littoral charr and profundal charr) were reared separately but under identical conditions. Their feeding behaviour was compared experimentally using different kinds of live prey. The fishes had no experience with natural prey before the experiments. The littoral morph were more effective in eating live plankton ( Daphnia ) and littoral benthos ( Gammarus ), and had a higher attack rate against pleuston (surface prey, Gerris ) compared with the profundal morph. The two morphs behaved in accordance with expectations from their in situ niche utilisation towards the three prey types. This indicates a case of incipient ecological speciation where divergence in resource utilisation in contrasting niches has evolved adaptations in feeding behaviour by natural selection.