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Burridge, CP and Craw, D and Waters, JM, An empirical test of freshwater vicariance via river capture, Molecular Ecology, 16, (9) pp. 1883-1895. ISSN 0962-1083 (2007) [Refereed Article]
Copyright Statement
The definitive published version is available online at: http://interscience.wiley.com
Official URL: http://interscience.wiley.com
DOI: doi:10.1111/j.1365-294X.2006.03196.x
Abstract
River capture is a geomorphological process through which stream sections are displaced
from one catchment to another, and it may represent a dominant facilitator of interdrainage
transfer and cladogenesis in freshwater-limited taxa. However, few studies have been
conducted in a manner to explicitly test the biological significance of river capture. Here we
present a multispecies phylogeographical analysis to test whether the nonmigratory fish
fauna of the Von River (South Island, New Zealand) is the product of a well-documented,
Late Quaternary capture of a section of the Oreti River (Southland drainage). Specifically,
we predict that nonmigratory fishes of the Von River will exhibit closer genetic affinities
with those of Southland, rather than those of the Clutha system, into which the Von River
presently drains. Mitochondrial DNA phylogeography (control region and cytochrome
b
sequence data) and analysis of nuclear orthologues of mtDNA sequences indicate that
‘flathead’
Galaxias
of the Von River (
n
= 31, three sites) have greatest genetic affinities with
those of Southland (
Galaxias ‘southern’
,
n
= 216, 38 sites), rather than with those of the
Clutha River (
Galaxias
sp. ‘
D
’,
n
= 73, 32 sites). Likewise, Von River ‘roundhead’
Galaxias
(
n
= 52, four sites) have greatest genetic affinities with those of Southland drainages
(
Galaxias gollumoides
,
n
= 223, 58 sites), rather than with those of the Clutha River
(
Galaxias pullus
,
Galaxias anomalus
,
Galaxias gollumoides
of the Nevis tributary;
n
= 68, 32
sites). These findings are consistent with our predictions that genetic affinities of the
nonmigratory fish fauna in the Von River would reflect past, rather than present, drainage
connections. Consequently, river capture is responsible for the nonmigratory fish fauna of
the Von River. In a broader context, river capture has frequently influenced the distribution
of genetic lineages among catchments in New Zealand freshwater-limited fish, and its
biogeographical significance may have been underestimated in other regions.
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