Pyrenean Brook Salamander or Pyrenean Brook Newt
Calotriton asper formally Euproctus asper
Euprocte des Pyrénées
Long classified in the genus Euproctus this urodele is now classified in the genus Calotriton because it belongs to an evolutionary line quite distinct from that of the "true Euproctes" of Corsica and Sardinia: it is actually closer to the great newts of the genus Triturus (Marbled Newt, Crested Newt) than Euproctus.
The head, trunk and tail are bristling with characteristic conical micro-warts (hence the name of the species, "asper" from the French "aspérité") and the fingers end in blackish pseudo-claws that allow the animal to effectively grip immersed rocky substrates, even where there is a noticeable current. The general colour of the body is blackish, brownish or greyish, with the exception of a yellow vertebral band (sometimes yellow spots are scattered on the flanks) and a red-orange belly.
They occupy rivers, streams and small lakes with clear, well oxygenated waters where they spend the whole year providing the conditions allow it. At altitude, however, the entire body of water is often covered by ice and snow in winter, forcing them to stay in deep, frost-free places such as crevices and tunnels. In some places such as the Grotte de Siech in Ariége there are populations that live in underground rivers, streams and pools.
They can occasionally be observed at low altitude from 150 m on the Spanish side and 250 m on the French side, but the vast majority of populations occupy the mountain and sub alpine levels extending roughly between an altitude of 1000 to 2000 m. They are not a species of higher altitudes, rarely found above 2,200 m.
The breeding season begins as soon as the water starts to warm up in spring. In order to "seduce" the females, the males adopt a very original posture of raising the tail so that it forms practically a right angle with the body. This visual signal is accompanied by a release of pheromones that stimulate the female. During mating, which lasts several hours, the two partners remain closely entwined, the male powerfully gripping the female by means of its tail. A few days following mating the females begin to lay eggs one by one under submerged stones, usually in shallow, low-flow waters. The eggs hatch after about six weeks; the larvae have external gills and are entirely carnivorous. They may over winter one or more times before metamorphosis and become mature in two or more years, depending on altitude, with the females taking longer. The juvenile newts are a dark colour with a thin, yellow line along the spine.
Lifespan can be as much as 20 years.
They consume a mainly aquatic diet of invertebrates such as small molluscs, crustaceans or insects.
Listed as vulnerable in France threats are mainly as a result of human activity. Salmonids, (Brown trout, Salmon, Arctic char, etc.), are the main predators of the larvae (the adults seem to be spared), but these fish are especially formidable food competitors because they feed on the same prey. This is a significant threat as about 70% of Pyrenean lakes were historically fish free before the introduction of these species and in many cases there are now localised extinctions of amphibians in these lakes. Releases of salmonids are still continuing today at a steady pace and it’s yet another example, (along with forestry in this case), of the manner in which exploitation or commercialisation of the natural habitat is causing great harm to native species.