Amphibians
Shovel-nosed Salamander
Desmognathus marmoratus · also called shovelnose salamander
Most salamanders spend at least part of their lives on land. The shovel-nosed salamander does not. It hatches, grows, and dies underwater, jammed into the gaps between stones in the coldest, fastest Appalachian streams, and it has the flat body and blunt snout to prove it.
Overview
Desmognathus marmoratus is a fully aquatic lungless salamander of cold, fast, rocky mountain streams in the southern Appalachians. The body and head are strongly flattened, the tail is keeled for swimming, and the blunt snout is shaped like a small shovel for working between and under the stones.
A life in the rocks
It shelters under stones by day and forages over the gravel at night for mayfly, stonefly, and caddisfly larvae. It keeps a small gill slit into adulthood, and the female guards her eggs on the underside of a flat rock in the stream, where the larvae take two to three years to grow.
Status
Least Concern and common in good streams, but tied to a narrow band of clean, cold, silt-free mountain water and quick to vanish where a stream is warmed, dammed, or filled with sediment.
Shovel-nosed Salamander: common questions
Does the shovel-nosed salamander really never come out of the water?
Essentially, yes. It is one of the most fully aquatic members of the lungless salamander family. It hatches in the stream, its larvae grow in the stream, and the adults remain in the stream, sheltering under and among the stones of the bed by day and moving out over the gravel to forage at night. It is only very rarely found even on the damp bank, and unlike related species it does not make overland movements or use the surrounding forest floor. This tie to flowing water is total, which is why it is such a sensitive indicator of stream condition.
What is the shovel-shaped snout for?
Working into tight spaces in a fast current. The salamander presses its flattened head and body against the stream bed and uses the blunt, wedge-shaped snout to nose and push its way between and under stones, into the gravel, and along crevices where the water flow is reduced and where insect larvae hide. The same flattening that gives it the shovel snout also lowers its profile so the current does not lift it off the bottom. It is not a powerful digger like a mole; the snout is more of a pry bar and a plough for a life spent squeezing through rock piles underwater.
How do I tell it from the black-bellied salamander?
They overlap in the same streams and are both dusky dark salamanders of fast water, so it takes a close look. The shovel-nosed salamander is more strongly flattened overall, with a distinctly squared or truncated snout when seen from above, a belly that is grey or mottled rather than solid jet black, and usually a row of paired light spots running down each side of the back. The black-bellied salamander is bulkier, has a more rounded snout, a uniformly black belly, and grows noticeably larger. Size alone often separates a big black-bellied salamander from a shovel-nosed, though young animals are harder.
Why does it matter as an indicator species?
Because it will only live where the water is genuinely healthy. The shovel-nosed salamander needs a stream that is cold, fast, highly oxygenated, and floored with clean loose rock, with no fine sediment filling the gaps between the stones. Logging, road construction, and development send silt into headwater streams and smother that habitat; dams slow and warm the water; and acid deposition lowers the pH. Any of these will remove the shovel-nosed salamander from a stretch of stream even while more tolerant species hang on, so biologists use its presence and abundance as a quick read on how intact a mountain stream really is.