Montseny brook Newt, Trito del Montseny, Triton del Montseny
Species Description: Carranza S, Amat F 2005 Taxonomy, biogeography and evolution of Euproctus (Amphibia: Salamandridae), with resurrection of the genus Calotriton and description of a new endemic species from the Iberian peninsula. Zool J Linn Soc 145:555-582.
© 2006 César L. Barrio Amoros (1 of 9)
Calotriton arnoldi is similar to Calotriton asper but mitochondrial DNA sequences differ and there are a few morphological and coloration differences, such as smaller size and fewer spiny-tipped tubercles on the dorsum in C. arnoldi. Calotrion asper also has a light and very thin brownish-orange stripe that extends from its base to the tip of its tail that is absent in C. arnoldi (Carranza and Amat 2005).
In life, the dorsum is dark and is a chocolate color with occasional light silvery-gold stippling on the sides. The pink-ivory throat is very light and is largely unspotted or has a lightly dark stippling. The venter is translucent and is a light ochre-brown color; it has dark markings that are the same color as the dorsum and has dark stippling on the sides. The cloaca has a bright reddish-orange tip. In preservative, it is a dark chocolate brown color the greyish tinge on the dorsum. The flanks and the tail sides have scattered, irregular, pale grey spots. Its underside is dark cream and is brighter under the tail. The belly is partly translucent with ambiguous dark markings on the side that consist of dark stippling. The throat has a large dark blotch and is posterior to the gular region. The throat, upper lip margins, underside of tail, and ulnar and palmar aspects of the limbs are immaculate and pale, and the tips of the digits are dark brown (Carranza and Amat 2005).
There is a variation in the pattern of the coloration of this species. The eastern population has irregular pale yellow spots on the trail and body flanks that are more abundant and apparent in post-meta-morphic newts than adults. The males of the western population have a whitish margin of snout. The pigmentation on the belly also displays slight variability that is most likely the result of individual variation and not seasonal variation (Carranza and Amat 2005; Valbuena-Ureña et al. 2013).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
The Calotriton genus has a reduction or absence of lungs that lowers the buoyancy and reduces the chances of getting carried away by currents, which is why it is necessary for them to live in oxygen-rich environments (Carranza and Amat 2005).
There are no recorded observations mating in C. arnoldi, but the courtship behavior of the genus consists of males using their tails to capture and overcome the females while transferring one or more spermatophores directly into her cloaca (Carranza and Amat 2005).
Trends and Threats
The species may possibly be threatened by pigmented skin tumors. Currently, the tumor has been restricted to the dermis and has not invaded the underlying lymph sacs or internal organs; this suggests that the tumor is benign. No skin tumors have been found in juveniles and there is a positive correlation between body size, snout-vent length, and the number of skin tumors. The source of the skin tumors is currently known, but analyses have ruled out water pollution and water composition as causes and the conditions of the newt’s habitat make ultraviolet-B radiation unlikely (Martinez-Silvestre et al. 2011).
Possible reasons for amphibian decline
General habitat alteration and loss
Calotriton arnoldi split off from Calotriton asper 1.1 - 2 million years ago during the Pleistocene. While their distribution ranges are only separated by 25 km, they have evolved independently ever since. Additonally, although there are still similarities in morphology and behavior between the two species, there have not been any signs of hybridization, likely because of geographic isolation (Valbuena-Ureña et al. 2013).
Calotriton arnoldi is named after Dr. E. N. Arnold who is a British herpetologist with a life-long dedication and contribution to herpetology, especially European herpetology. He also guided the senior author of the species authority paper (Carranza and Amat 2005).
Carranza, S and Amat, F. (2005). ''Taxonomy, biogeography and evolution of Euproctus(Amphibia: Salamandridae), with the resurrection of the genus Calotriton and the description of a new endemic species from the Iberian Peninsula.'' Zoological Journal of the Linnean Society, (145), 555-582.
Carranza, S and Martínez-Solano, I (2009). ''Calotriton arnoldi. In: IUCN 2013.'' ''.'' IUCN Red List of Threatened Species. Version 2013.1.
Martínez-Silvestre, A. et al. (2011). ''Incidence of pigmented skin tumors in a population of wild Montseny brook newt (Calotriton arnoldi).'' J. Wildlife Diseases, 47, 410-414.
Valbuena-Ureña, E., F. Amat, and S. Carranza (2013). ''Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).'' PLoS ONE, (8), 1-12.
Written by Samantha Morco (smorco AT berkeley.edu), UC Berkeley
First submitted 2013-11-20
Edited by Ann T. Chang (2014-03-05)
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