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Genetic population structure of the catadromous Perciform: Macquaria novemaculeata (Percichthyidae)
Author(s) -
Chenoweth S. F.,
Hughes J. M.
Publication year - 1997
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1997.tb01967.x
Subject(s) - biology , population , genetic structure , mtdna control region , population fragmentation , phylogeography , gene flow , phylogenetic tree , evolutionary biology , zoology , genetic variation , ecology , genetics , genotype , haplotype , gene , demography , sociology
Genetic population structure in the catadromous Australian bass Macquaria novemaculeata was investigated using samples from four locations spanning 600 km along the eastern Australian coastline. Both allozymes and mtDNA control region sequences were examined. Population subdivision estimates based on allozymes revealed low levels of population structuring ( G st =0·043, P <0·05). However, mtDNA indicated moderate levels of geographic population structure ( G st =0·146, P <0·0l). Phylogenetic analysis of mtDNA control region sequences (mean sequence divergence 1·9%) indicated little phylogeographic structuring. Results suggested that genotypic variation within each river population, while being affected primarily by genetic drift, was also prevented from more significant divergence by homogenizing levels of gene flow—synonymous with a one‐dimensional stepping‐stone model of population structure. The catadromous life history of Macquaria novemaculeata was considered to be influential on the pattern of population structure displayed. Results were compared to the few population genetic studies involving catadromous fishes, indicating that catadromy alone is unlikely to be a good predictor of population structure. A more comprehensive suite of biological characteristics than simple life‐history traits must be considered fully to allow reliable predictive models of population structure to be formulated.