Although four different morphs coexist in Lake Thingvallavatn Iceland (two limnetic and two benthic), this research has dealt with two of them: Planktivorous (PL) and small benthic (SB), limnetic and benthic respectively.
Um er að ræða tvö botnlæg afbrigði kuðungableikju (Planktivorous, PL) og dvergbleikju (small benthic, SB), og tvö sviflæg afbrigði, murtu (small pelagic, SP) og sílableikju (Piscivorous, PI).