Interspecific hybridization of smallmouth and Guadalupe bass (Micropterus): evidence based on biochemical genetic and morphological analyses [Fish, Texas]

A rare incidence of natural interspecific hybridization has occurred in south-central Texas as a result of secondary contact between two allopatrically evolved species, smallmouth bass (Micropterus dolomieui) and Guadalupe bass (M. treculi). Hybridization was initiated by the stocking of smallmouth bass into the habitat of the endemic Guadalupe bass. The extent of hybridization and genetic introgression has been analyzed using a meristic index and diagnostic allozyme loci. Because hybridization is a relatively recent event, little evidence of genetic introgression was found. However, the possibility of future introgression remains as a threat to the genetic integrity of the Guadalupe bass population.