Salamanders with relatively flat head, small eyes and lacking parotoid glands. The skin is coarse and granular. Digits black and hardened distally. Can be distinguished from other (allopatric) species of Euproctus by the presence of a gular fold and the absence of spurs on the hind legs of males. Euproctus asper has a variable coloration, depending on geographic region, altitude and coloration of the substrate. The dorsum varies from gray and green to brown and black. Occasionally black spots are present. A yellow dorsal line, present in newly metamorphosed individuals, may fade with age or persist into adulthood. The venter is yellow to orange-red, and this coloration can extend to the ventral surfaces of the head and tail. Males are smaller (105-120 mm total length) than females (110-140 mm). Males usually have a relatively broader and longer head than females. The cloaca of the females is pear-shaped, bell-shaped or extended to a short tube. The cloacal opening is small and round and directed downward or backward. In males, the cloaca is hemispherical, and the opening is a longitudinal slit. The tail is shorter and higher in males than in females (Boehme et al 1999).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Andorra, France, Spain
The Pyrenean newt is restricted to the Pyrenean range. It is thus an endemic with a rather restricted distributional range. The species is one of several amphibians originating in the Mediterranean area after the Alpidic orogeny. The genus Euproctus already existed during the Oligocene, when the ancestors of today's species inhabited the Tyrrhenian microplate. This was later separated from the Iberian Peninsula and the populations left on the mainland became differentiated during the Miocene, resulting in the current Pyrenean species. The range of the species has changed in the past following climatic changes and it is now probably smaller than it formerly was. The species was formerly described as restricted to central Pyrenees, but is now known to inhabit the whole chain. The easternmost populations are those of La Junquera, near the eastern end of the Spanish-French border. The westernmost locality is the Sierra de Aralar, between the Basque Country and Navarre, clearly outside the main Pyrenean range. The southern extremity of the area is the Montseny Mountain, between the provinces of Barcelona and Gerona, which is now known to be not an isolated population but connected to the main Pyrenean populations. The northernmost locality is near St. Jean Pied de Port, in the French Basque Country; some specimens, however, have been carried northwards, by water, up to Toulouse.
Altitudinal distribution is very wide: the lowest locality is the Lac de Banyoles, in Cataluñia, at 175 m. and the highest is the Pic de Cambalés, at 2900 m (probably a mistake and should be Lac de Cambalés, in Hautes Pyrénées, 2500-2600 m). There are indications of the presence of the species above 2600 m., but without a precise locality (Gasc 1997).
Euproctus asper Inhabits clear oxygen-rich mountain streams and mountain lakes and ponds. It prefers rocky substrates and avoids muddy waters. It also a facultative inhabitant of subterranean water bodies (Ublein et al 1992).
Life History, Abundance, Activity, and Special Behaviors
Euproctus asper has a tendency toward an aquatic lifestyle. Their flattened body shape enables them to crawl under rocks. They are nocturnally active. This species breeds shortly after the melting of the snow. The populations on the north side of the Pyrenees avoid water temperatures above 15ºC, while populations on the south side live in water up to 17.5ºC. Egg laying and spermatogenesis occur in the aquatic phase of the annual cycle. At 2400 m the aquatic period is from July to September, at 1000 m from May to November and at 300 m from September to May-June. The animals at low altitudes leave the water in summer. Cave-dwelling individuals differ from surface-dwelling ones in reproductive periodicity due to lack of light stimulation. Mating behavior in Euproctus asper is variable and can start with active mate searching by the male, or by a signaling stance, in which the male raises his tail into a near-vertical position. This signaling stance can be maintained for several hours. When a mate is found, or comes near a male in signaling stance, the male restrains the female by wrapping his tail around her cloacal region. Then the male starts to move his hind legs in a slow and rhythmic manner, presumably to stimulate the females cloacal region. The hind legs of the male are held in such a way that they catch the spermatophores, which are subsequently maneuvered into the females' cloaca. After mating the male releases the female. The female lays her eggs in crevices and cracks in well-oxygenated water. Females lay 20 to 30 eggs annually and these are 3.5 to 5 mm in diameter, not taking the gelatinous envelope into account. At medium elevation (1000 m) the larval stage lasts about 14 months. The larvae metamorphose the second summer. At higher elevations (2000 m) the larval stage can last 2 years and they metamorphose the third summer. At higher elevations the larvae can grow to 95 mm before metamorphosis. Neotenic animals have been found in the Valle de Arán. Metamorphosis is slow and takes a month at 12ºC. The newly metamorphosed salamanders are dark with a yellow middorsal line and a yellow lateral band or spots. Sexual maturity is reached after two years at 1000 m, and after 2.5-3 years for males and 4 years for females at 2000 m (Boehme et al 1999). Euproctus asper can probably live as long as 20 years (Noellert and Noellert 1992).
Trends and Threats
Across most of its range the populations do not seem to face any major problems, the animal being abundant and easily found in many places. However in certain peripheral localities, newts are scarce and several populations have disappeared. Destruction of the habitat is the main problem due to damming of mountain brooks, opening of new roads, pollution by campers and so on. Other problems are the introduction of game fish and chemicals. Because its food consists of insects and because the common habitat of the species is the mountain pond, which gathers the surrounding waters, even minute quantities of pesticides will eventually accumulate in its body. Although the use of pesticides in mountain areas is low, some populations of Pyrenean newt show contamination by these substances. The present distribution limits are not biogeographic. Formerly, the species was found in other mountain ranges, but peripheral populations have apparently become extinct. The actual distributional limits define not the lack of capability to colonize over lands, but the places where access by man is hampered. The whole range is still shrinking, although it has shown an artificial increase in recent years due to newly available data (Gasc 1997).
Possible reasons for amphibian decline
General habitat alteration and loss
Dams changing river flow and/or covering habitat
Local pesticides, fertilizers, and pollutants
Predators (natural or introduced)
Boehme, W., Grossenbacher, K., and Thiesmeier, B. (1999). Handbuch der Reptilien und Amphibien Europas, band 4/I:Schwanzlurche (Urodela). Aula-Verlag, Wiesbaden.
Gasc, J.-P. (1997). Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica, Bonn, Germany.
Nöllert, A. and Nöllert, C. (1992). Die Amphibien Europas. Franckh-Kosmos Verlags-GmbH and Company, Stuttgart.
Uiblein, F., Durand, J. P., Juberthie, C., and Parzefall, J. (1992). ''Predation in caves: the effects of prey immobility and darkness on the foraging behaviour of two salamanders, Euproctus asper and Proteus anguis.'' Bahavioural Processes, 28, 33-40.
Written by Arie van der Meijden (amphibia AT arievandermeijden.nl), Research associate, Museum of Vertebrate Zoology, UC Berkeley
First submitted 1999-10-05
Edited by David B. Wake (Jan., 2000) (2002-05-25)
Species Account Citation: AmphibiaWeb 2002 Calotriton asper: Pyrenean brook salamander <http://amphibiaweb.org/species/4251> University of California, Berkeley, CA, USA. Accessed Jul 1, 2020.
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Citation: AmphibiaWeb. 2020. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 1 Jul 2020.
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