Genetic evidence of multiple matrilineal lineages of the channel catfish, Ictalurus punctatus in North America

Using mitochondrial DNA control region (mtDNA CR) sequence data the present study evaluates the genetic status of the wild populations of channel catfish, Ictalurus punctatus, in North America. A total of 584 individuals representing 56 drainages across its distributional range in the United States were collected. There were 105 mtDNA CR haplotypes defined by 51 variable sites. Phylogenetic analyses have revealed the existence of six distinct matrilineal genetic lineages of channel catfish in the United States. Four of these lineages were restricted to southeast Gulf Coast, a region that never glaciated during the Pleistocene. While samples from the Mississippi river and its tributaries represent a single genetic lineage, samples from the southeast Atlantic coastal plain drainages formed a unique lineage. Each lineage should be regarded as an evolutionarily significant unit/management unit and therefore separate management and conservation strategies should be undertaken in order to conserve the genetic resources.