is normally lighter in colour in comparison to the body. Adults attain lengths of up to 14 cm, with the average length of adult males and females being 9.4 cm and 8.6 cm, respectively. Being from the family Plethodontidae, the northern dusky salamander is lungless. It absorbs oxygen through the skin and membranous tissue located in the mouth and throat. The dusky salamander also has a naso-labial groove, which aids olfaction, and thus the ability to search out mates and prey through smell. Similar species The dusky salamander is similar in appearance to and thus often confused with the Allegheny Mountain dusky salamander (Desmognathus ochrophaeus). Distinguishing characteristics are that the dorsal spots of the Mountain dusky salamander are usually chevron-shaped and its tail rounded at the base rather than laterally compressed. Additionally, hybridization has been known to occur between the Allegheny Mountain dusky salamander and the northern dusky salamander. The northern dusky salamander can also be differentiated from other lungless salamanders including the eastern red-backed, the northern two-lined and the four-toed. They have a distinguishing pale-coloured line that runs from behind their eyes to the rear of the jaw, and heavier set bodies with longer hind legs than front legs. Range This species is native to North America, and occurs throughout central-eastern regions of Canada and the United States, from southern New Brunswick , southeastern Quebec and southern Ontario south to South Carolina. Populations south of this range are now thought to belong to other, previously-synonymized species such as D. conanti. The Canadian distribution accounts for approximately 5% of the global range. Within its Canadian range, the northern dusky salamander usually occurs in forested habitat located in high elevation, low-order streams. There are two separate units (DU), the Quebec/New Brunswick DU and the Carolinian DU in Ontario. Ohio populations are reviewed in "Amphibians of Ohio" (2013). An isolated breeding population exists in eastern Michigan; however, it is not known whether this population is natural or was introduced. Habitat In the northern extent of their range, the northern dusky salamander inhabits saturated soil near springs, seepages, and small tributaries of small headwater streams otherwise known as the riparian zone. Habitat quality is optimal in undisturbed watersheds and where water is running or trickling and there is an abundance of forest cover The forest cover serves to keep the water cool and well oxygenated, and maintains moisture and temperature at levels necessary