Pyrenean Brook Salamander, Calotriton asper

The Pyrenean Brook Salamander (Calotriton asper) is a species of salamander belonging to the Salamandridae family. It is located in the Pyrenees of Andorra, France, and Spain.

Its natural habitats include temperate forests, intermittent rivers, rivers, freshwater lakes, freshwater marshes, caves, and inland karsts. It is threatened by loss of habitat.

This salamander can grow to about 3.6 inches long, half of which is the laterally flattened tail. The females are normally larger than the males. The body is sturdy with a flattened head and small eyes. The limbs are short. There are no parotoid glands and the skin is blanketed with small and rough tubercles. The coloration is very variable, the upper side normally being some shade of olive, grey, charcoal, or muddy brown, occasionally mottled with ochre, with an intermittent yellowish stripe running down the spine. The underside has a row of dark colored splotches at either side and the center is orange, red, or yellow. The male has a rounded cloacal swelling, while the female has a conical one.

It is native to the Pyrenees and surrounding mountains and it can be found at altitudes ranging from 2,300 to 8,200 feet. It’s mostly an aquatic species, normally frequenting slow-moving streams and shallow mountain lakes. It shows a preference for water below 59 degrees Fahrenheit with scarce vegetation on rocky or pebbly bottoms. Some Pyrenean brook salamanders reside entirely inside caves where they breed over a long period of the year because of the lack of day length stimulus.

This salamander isn’t frequently seen, though it is active by day, as well as by night. It’s mostly aquatic during the summer. The diet is made mostly of other slow-moving invertebrate prey, and is itself eaten by trout, so it is frequently scarce in locations in which they are abundant. It is sensitive to pesticides within the water which are absorbed through the skin and accumulate in the tissues.

The salamander occasionally aestivates in hot weather in the lower portions of its range. It hibernates during the winter on land at higher altitudes, emerging in the spring. During courtship, the male salamander displays his brightly colored underparts before grasping the female around the loins with his tail and transferring one to four spermatophores directly into her cloaca in a process that lasts several hours. The female lays 20 to 40 eggs over the course of a few weeks, sticking them to rocks or inside crevices using her extensible cloaca. The eggs hatch after about six weeks; the larvae have external gills that are completely carnivorous. They may overwinter one or more times before metamorphosis and become mature in two or more years, depending on the altitude, with the females taking long. The juvenile newts are a dark color with a thin yellow line running down the spine.

Image Caption: Pyrenean Brook Salamander, Calotriton asper. Credit: DAGOR53/Wikipedia (CC BY-SA 3.0)