Preliminary phylogenetic analysis of selected subterranean amphipod crustaceans, using small subunit rDNA gene sequences

AbstractThe exclusively subterranean amphipod genus Bactrurus (Crangonyctidae) occurs in central and eastern parts of the United States. Bactrurus is characterized by morphologically similar species. In at least one instance, the distinction between separate species and geographic variants appears to be blurred. A sequence analysis of the small subunit (18S) rDNA gene was conducted for eight amphipod taxa. Both maximum likelihood and distance methods resulted in phylogenies for several species of Bactrurus that are in accordance with morphological data. These results could not be validated by a parsimony analysis. All three methods of phylogenetic inference, however, produced identical basal branching patterns. The molecular analyses do not support the recognition of what initially appeared to be a new species of Bactrurus from glaciated areas in Montgomery County, Illinois