Salamanders of the genus Desmognathus have a distinctive feeding and defensive mechanism. Muscles and ligaments connecting the back of the skull to the vertebral column allow the animal to lift the entire head, opening the mouth by raising the upper jaw rather than only lowering the lower one. The associated jaw musculature is heavy, and the neck region is thickened and pale-lined.
The result is a strong bite used both on prey and against rivals and predators, including larger salamanders. Duskies are aggressive for their size, and biting features in territorial encounters at seepage sites where good cover is limited. Their enlarged hind limbs also let them jump and flip away from a grabbing predator.
The genus is a taxonomic minefield. Desmognathus fuscus as traditionally applied has been repeatedly split, and species boundaries in the group continue to move as genetic work accumulates, so identifications from older sources and field guides may not correspond to currently recognised species.