Amphibians
Web-toed Salamander
Hydromantes · also called web-toed salamander, web-toed salamanders
A web-toed salamander lives on sheer, wet rock and cave walls, and it has two remarkable tools for the job. It uses its tail as a fifth leg — bracing, counterbalancing, even hanging from it. And it feeds by firing its entire tongue skeleton out of its mouth, hitting prey in a few thousandths of a second, one of the fastest movements known in any animal with a backbone.
Overview
Web-toed salamanders are the genus Hydromantes, lungless salamanders of steep rock, talus, and caves. They have webbed toes, a flat body, and a prehensile tail, and they breathe entirely through skin and mouth lining, which ties them to cool, damp places and shuts them down in heat.
The ballistic tongue
To catch a springtail or a fly, the salamander shoots its whole tongue apparatus clear of its mouth, reaching up to 80% of its body length in 2–10 milliseconds. The power comes from elastic tissue loaded like a catapult and released all at once — far more power per gram of muscle than muscle can generate directly.
A puzzle of a map
The genus lives in just two places, an ocean apart: the mountains of California and the limestone caves of Italy, southern France, and Sardinia. They are the last survivors of a group once spread across the Northern Hemisphere. Like other lungless salamanders, they lay a few large eggs in a damp crevice and the young hatch as tiny land salamanders — no water needed.
Status
Near Threatened overall, with several species of concern. Californian species have small ranges hit by dams (a proposed Shasta Dam raise would flood habitat), logging, and a drying climate; European cave species are sensitive to cave disturbance and quarrying.
Web-toed Salamander: common questions
How fast is a web-toed salamander's tongue?
Extremely fast. The salamander fires the entire skeleton of its tongue out of its mouth, and the projectile reaches the prey in roughly two to ten milliseconds, faster than the animal's nervous system could control mid-flight, so the strike is fully committed the moment it starts. The power comes from elastic tissue that is loaded like a bow or a catapult by slow muscle contraction and then released all at once, giving a burst of power output per unit of muscle far beyond what muscle can produce directly. It is among the fastest movements measured in any backboned animal.
Why does it use its tail to climb?
Web-toed salamanders live on steep, slick, wet rock and cave walls where a slip can be fatal, and the tail gives them extra points of contact and control. They press or coil the tail against the surface as a brace while reaching with a foot, use it as a counterweight when leaning out, and can even hang from it briefly. Combined with the broad webbed feet, which spread the load and grip like small suction surfaces, the tail lets these salamanders move confidently over terrain that would defeat most amphibians.
How can the same salamanders live in both California and Italy?
It is one of the best-known oddities in animal distribution. The explanation is that this group of lungless salamanders was once spread widely across the Northern Hemisphere, and the populations in California and in southern Europe are the last survivors at opposite ends of that former range, with everything in between having died out. Their closest relatives are the many lungless salamanders of the Americas, which supports the idea that the family arose in the New World and reached Europe long ago. Molecular dating puts the split between the American and European web-toed salamanders many millions of years back.
Do web-toed salamanders need water to breed?
No. Like the other lungless salamanders of their group, they have done away with the aquatic tadpole stage entirely. The female lays a small clutch of large, yolky eggs in a constantly damp, sheltered place, typically deep in a cave or a rock crevice, and stays with them, and the embryos develop all the way to a tiny land-going salamander inside the egg before hatching. This frees the animals from any need for ponds or streams and is part of why they can live on dry-looking cliffs and in caves, as long as there is enough moisture in the rock.