The slimy salamander has mainly black skin, covered by abundant silver-white or brassy specks, or both; the ventrum has variable shades but is generally lighter than the dorsum. The organism is distinguished from other dark salamanders in its range by the presence of a nasolabial groove. More noticeably, P. glutinosus is defined by a slimy, glue-like secretion released from its skin glands. It has 16 costal grooves, on rare occurrences 15 or 17, and generally ranges from 4.75 to 6.75 inches in length (Conant and Collins 1998). Hatchlings are born with only slight dark coloration on the dorsum and none on the ventrum; melanin for the specks begins to appear on the dorsum after three days. Adult females exhibit slightly larger snout-to-vent lengths than adult males, but are otherwise similar in appearance (Highton 1956).
Average mass: 4.2 g.
Average basal metabolic rate: 0.00191 W.