Fisheries Research Articles
Contrasting patterns of genetic structure in two species of the coral trout Plectropomus (Serranidae) from east and west Australia: Introgressive hybridisation or ancestral polymorphisms
Document Type
Article
Publication Date
5-10-2006
Journal Title
Molecular Phylogenetics and Evolution
ISSN
Print: 1055-7903 Electronic: 1095-9513
Keywords
Mitochondrial and nuclear sequences, Introgressive hybridisation, Incomplete lineage sorting, Abundance, Regional histories, Sea-level change
Disciplines
Aquaculture and Fisheries | Ecology and Evolutionary Biology | Genetics | Genomics | Natural Resources and Conservation | Natural Resources Management and Policy | Physical and Environmental Geography | Population Biology | Spatial Science
Abstract
Inter-specific genetic relationships among regional populations of two species of grouper (Plectropomus maculatus and Plectropomus leopardus) were examined using mitochondrial and nuclear markers. mtDNA revealed contrasting regional inter-specific patterns whilst nuclear markers revealed contrasting patterns among markers, irrespective of region. In eastern Australia (EA) the species form a single mtDNA lineage, but the two species are reciprocally monophyletic in Western Australia (WA). This supports previous evidence for hybridisation between these species on the east coast. WA P. leopardus forms a sister relationship with the EA P. leopardus-maculatus clade while WA P. maculatus is more basal and sister to the P. leopardus lineages, indicating mtDNA does not suffer from incomplete lineage sorting for these species. In contrast, one of three nuclear markers (locus 7-90TG) differentiated the species into two reciprocally monophyletic clades, with no evidence of hybridisation or ancestral polymorphism. The remaining two nuclear markers (2-22 and ETS-2) did not separate these two species, while distinguishing other plectropomid species, suggesting incomplete lineage sorting at these nuclear loci. These results together with coalescence analyses suggest that P. leopardus females have hybridised historically with P. maculatus males and that P. maculatus mitochondria were displaced through introgressive hybridisation and fixation in the P. maculatus founder population on the Great Barrier Reef. The contrasting regional patterns of mtDNA structure may be attributed to Quaternary sea-level changes and shelf width differences driving different reef configurations on each coast. These reef configurations have provided opportunities for local scale interaction and reproduction among species on the narrower EA continental shelves, but not on the broader WA continental shelves.
Recommended Citation
L. van Herwerden, J.H. Choat, C.L. Dudgeon, G. Carlos, S.J. Newman, A. Frisch, M. van Oppen, Contrasting patterns of genetic structure in two species of the coral trout Plectropomus (Serranidae) from east and west Australia: Introgressive hybridisation or ancestral polymorphisms, Molecular Phylogenetics and Evolution, Volume 41, Issue 2, 2006, Pages 420-435, ISSN 1055-7903, https://doi.org/10.1016/j.ympev.2006.04.024.
