Molecular Phylogenetics and Biogeography of Galaxiid Fishes (Osteichthyes: Galaxiidae): Dispersal, Vicariance, and the Position of Lepidogalaxias salamandroides

Jonathan M. Waters, J. Andrés López, Graham P. Wallis, M. Westneat
2000 Systematic Biology  
The galaxiid shes exhibit a gondwanan distribution. We use mitochondrial DNA sequences to test con icting vicariant and dispersal biogeographic hypotheses regarding the Southern Hemisphere range of this freshwater group. Although phylogenetic resolution of cytochrome b and 16S rRNA sequences is largely limited to more recent divergences, our data indicate that the radiation can be interpreted as several relatively recent dispersal events superimposed on an ancient gondwanan radiation. Genetic
more » ... lationships contradict the ndings of recent morphological analyses of galaxioid shes. In particular, we examine several hypotheses regarding phylogenetic placement of the enigmatic Lepidogalaxias. Although most workers consider Lepidogalaxias to be an unusual scaled member of the Southern Hemisphere galaxioids, it has also been suggested that this species is related to the Northern Hemisphere esocoids. Our data strongly suggest that this species is not a galaxiid, and the alternative hypothesized esocoid relationship cannot be rejected. The species-rich genus Galaxias is shown to be polyphyletic and the generic taxonomy of the Galaxiinae is reassessed in the light of phylogenetic relationships. Juvenile saltwater-toleranc e is phylogenetically distributed throughout the Galaxiinae, and the loss of this migratory phase may be a major cause of speciation.
doi:10.1080/106351500750049824 pmid:12116439 fatcat:qfjobu6yxncndhllhr6jl76qtu