Evidence for cryptic speciation in Australian freshwater eel-tailed catfish, Tandanus tandanus (Teleostei: Plotosidae)

Abstract

Allopatric populations of Australian freshwater eel-tailed catfish, Tandanus tandanus, were compared morphologically and electrophoretically. Five populations from east of the Great Dividing Range and six from within the Murray-Darling basin, west of the Great Dividing Range, were sampled. An absence of morphological differentiation among all populations was in contrast to electrophoretic evidence in which fixed allelic differences revealed three discrete gene pools: (1) an undescribed species from the Bellinger River; (2) a second undescribed species from the Nymboida River; and (3) the remaining populations that were genetically similar to one another. Mean heterozygosity in all populations ranged from 0.000-0.011.