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DOES FISH ECOLOGY PREDICT DISPERSAL ACROSS A RIVER DRAINAGE DIVIDE?
Author(s) -
Burridge Christopher P.,
Craw Dave,
Jack Daniel C.,
King Tania M.,
Waters Jonathan M.
Publication year - 2008
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2008.00377.x
Subject(s) - biological dispersal , biology , ecology , phylogeography , vicariance , taxon , genetic structure , population , phylogenetics , biochemistry , demography , sociology , gene , genetic variation
Obligate freshwater taxa are frequently distributed among catchments isolated by marine and terrestrial barriers. Such distributions can arise through vicariant changes in drainage geometry, or dispersal via intermittent freshwater connections. We employed two adjacent rivers in southern New Zealand to test for interdrainage dispersal while controlling for historical drainage geometry, and analyzed four ecologically distinct freshwater‐limited fish taxa to assess any relationship with habitat preference. Individuals from the Mararoa and Oreti catchments ( n >100 per species) were sequenced for a minimum of 1297 bp of mitochondrial DNA (cytochrome b and control region). Phylogeographic relationships were consistent with ecological expectations of interdrainage dispersal capability, with the two obligate riverine taxa each exhibiting reciprocal monophyly between catchments, whereas the two facultative swamp dwellers revealed paraphyletic relationships, one of which shared a haplotype between catchments. Statistical phylogeography, accommodating taxon‐specific mutation rates and the known age of the last major riverine connection between these catchments, rejected complete isolation of populations for one of the swamp dwellers. Therefore, dispersal across a young (145–240 kyr) drainage divide is inferred for one species, and can be predicted to some extent by species ecology. Moreover, our study highlights the importance of historical drainage geometry when assessing the causes of contemporary genetic structuring in freshwater taxa.