Overview
Dunn’s Salamander (Plethodon dunni) is a handsome, lungless woodland salamander endemic to the cool, rain-drenched coastal ranges of the Pacific Northwest. Completely lacking lungs and breathing entirely through its moist, vascularized skin and the lining of its mouth, this secretive amphibian thrives in the perpetually humid splash zones of rocky mountain creeks and moss-covered talus slopes.
Biology and Physical Characteristics
Plethodon dunni possesses a slender, elegant body colored dark slate-grey to purplish-black, illuminated down its back by a broad, ragged-edged dorsal stripe that ranges from greenish-yellow to bright mustard-gold, fading before reaching the tip of its tail. Its flanks are finely speckled with silvery-white flecks, and it features long, slender toes with four digits on the forelimbs and five on the hindlimbs.
Behavior and Ecology
A strictly terrestrial breeder with no aquatic larval stage, Dunn’s Salamander lays small clutches of gelatinous eggs hidden deep inside cool, saturated rock crevices or rotting logs, where the female coils around them to prevent fungal infection. Fully formed miniature salamanders hatch directly from the eggs. It hunts nocturnal forest invertebrates, using a rapid, sticky tongue projection to capture springtails and beetles.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, Plethodon dunni maintains healthy populations across old-growth and mature secondary forests in the Oregon Coast Range. However, clear-cut logging and road construction that expose rocky talus to direct sunlight cause catastrophic microclimate warming and desiccation, rapidly extinguishing localized colonies.
Interesting Factoid
Dunn’s Salamander has no lungs whatsoever: it absorbs 100% of its oxygen directly through its wet, paper-thin skin, meaning it must live in perpetually dripping, moss-draped rock crevices to avoid suffocating.