title: Strong population genetic structure and its management implications in the mud carp Cirrhinus molitorella, an indigenous freshwater species subject to an aquaculture and culture-based fishery.
abstract: This study investigated population genetic structure and diversity of mud carp Cirrhinus molitorella, a species widely used in aquaculture and culture-based fisheries in China and Mekong River riparian countries. Seven newly developed and one published microsatellite DNA markers were used to analyse samples from six wild locations, four hatchery broodstocks and one farmed site from the Mekong, Red and Pearl Rivers. Significant genetic structure was detected in C. molitorella, with isolation-by-distance being a strong force in the Mekong. Pair-wise F(ST) , Fisher's exact tests for population differentiation, permutation tests and individual-based structure analysis all support the recognition of a sample originating from Toul Krasaing Lake (Cambodia) and one between Kratie and Stung Treng (Cambodia) as distinct from the remainder of the sampled range. Samples from the main upper Mekong and the Nam Khan River were significantly differentiated, but on a time scale inferred to be short (i.e. by genetic drift, not sufficient for evolution of new microsatellite alleles). The Mekong stock of C. molitorella was strongly differentiated from those from the Red and Pearl Rivers, inferred to be on an evolutionary time scale. Finer-scale sampling is warranted to further improve the understanding of genetic interactions among fish from the Mekong and its tributaries. Detailed studies on the ecology of C. molitorella (e.g. migration pathways and preferred spawning habitats) would provide useful information to explain the patterns of genetic structure detected here, and deepen insights about evolutionary distinctiveness of the population units.
authors.affiliation: School of Life and Environmental Sciences, Deakin University, Geelong Waurn Ponds Campus, Geelong, Vic 3217, Australia. thuy.nguyen@deakin.edu.au
authors.forename: T T T
authors.initials: TT
authors.lastname: Nguyen
authors.forename: P
authors.initials: P
authors.lastname: Sunnucks
mesh_terms: D000818:Animals; D002160:Cambodia; D003247:Conservation of Natural Resources; D003531:Cypriniformes / Q000235:genetics*; D005398:Fisheries; D005819:Genetic Markers; D014644:Genetic Variation; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats; D011157:Population Dynamics; D045483:Rivers
chemical_list: D005819:Genetic Markers