Did common disjunct populations of freshwater fishes in northern Australia form from the same biogeographic events?

Abstract

AbstractSeveral freshwater fishes have disjunct (geographically discrete and widely spaced) distributions across northern Australia. We used mitochondrial deoxyribonucleic acid (mtDNA) data and phylogeographic analyses to examine the origin of these common disjunct distributions and to test the hypothesis that they were a result of a single biogeographic event. These disjunct distributions are not perfectly shared among species, but we selected 3 species that have wide ranges with the most similar disjunct geographic overlap: Spotted Blue Eye (Pseudomugil gertrudae), Pennyfish (Denariusa australis), and MacCulloch’s Rainbow Fish (Melanotaenia maccullochi). Despite similarity in their present-day disjunct distributions, spatial genetic patterns varied considerably among the 3 species in terms of measures of molecular diversity, number of mtDNA lineages within each species, inter- and intra-regional spatial distribution of individual lineages within species, and degree of partitioning of genetic variation a...