University Of Tasmania

File(s) not publicly available

Extreme intraspecific mitochondrial DNA sequence divergence in Galaxias maculatus (Osteichthys: Galaxiidae), one of the world's most widespread freshwater fish

journal contribution
posted on 2023-05-16, 12:34 authored by Waters, JM, Christopher BurridgeChristopher Burridge
Biogeographic controversies surrounding the widespread freshwater fish,Galaxias maculatus,were addressed with DNA sequence data. Mitochondrial cytochromeband 16S rRNA sequences were obtained from representatives of six populations of this species. Substantial levels of cytochromeb(maximum 14.6%) and 16S rRNA sequence divergence (maximum 6.0%) were detected between western Pacific (Tasmania-New Zealand) and South American (Chile-Falkland Islands) haplotypes. A considerable level of divergence was also detected between Tasmanian and New Zealand haplotypes (maximum 5.1%) and within and among Chilean and Falkland Island G. maculatus (maximum 3.8%). The phylogenetic structure of haplotypes conflicts with the accepted pattern of continental fragmentation. Molecular clock calibrations suggest that haplotype divergences postdate the fragmentation of Gondwana. These findings point to marine dispersal rather than ancient vicariance as an explanation for the wide distribution. The phylogenetic structure of South American haplotypes was not consistent with their geographic distribution. We consider factors such as population divergence, population size, dispersal, secondary contact, and philopatry as potential causes of the high level of mtDNA nucleotide diversity in this species. © 1999 Academic Press.


Publication title

Molecular Phylogenetics and Evolution








Institute for Marine and Antarctic Studies


Academic Press Inc

Place of publication


Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the environmental sciences

Usage metrics

    University Of Tasmania