Pygmy Web-footed Salamander
Species Description: Bolanos F, Wake DB 2009 Two new species of montane web- footed salamanders (Plethodontidae: Bolitoglossa) from the Costa Rica-Panama border region. Zootaxa 1981:57-68.
Teeth are relatively large and well developed, with a range of 3-6 premaxillary teeth, 18-60 maxillary teeth, and 15-25 vomerine teeth found in females. For males, the number of premaxillary teeth vary from 2-3, 27-44 for maxillary teeth, and 14-20 for vomerine teeth.
In alcohol, specimens are a very pale brown and appear translucent, except for a strikingly conspicuous black patch of internal pigment visible on the posterior venter. This black patch covers the peritoneal area (posterior abdomen) and stomach, as well as the testes in males, and can be seen through the ventral and lateral body wall. A brown line extends from the snout through each eye and past each shoulder, continuing as a poorly-defined stripe to the pelvic region. These lines then diffuse into a pair of weak stripes running the length of the tail. Transparent gland openings appear as silver circles between the hindlegs and on the ventral surface of the tail. A few melanophores are visible on the ventral surfaces. The iris is dark brownish-black.
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
The specific epithet is derived from the Latin word pygmaeus, or pygmy, and the Greek word pygmaios, meaning dwarfish. It is currently the smallest salamander in the genus Bolitoglossa, smaller than B. minutula.
This species is thought to be miniaturized rather than paedomorphic, since its only paedomorphic trait is the lack of prefrontal bones (which are absent from many species of Bolitoglossa). Paedomorphic traits of small congeners such as B. occidentalis and B. rufescens include a less well-formed skull with an open dorsal fontanelle, the lack of vomerine teeth and mesopedial fusions in the limbs. These characters are not present in B. pygmaea. See Wake (1991) for a further discussion of miniaturization vs. paedomorphism.
Bolaños, F. and Wake, D. B. (2009). ''Two new species of montane web-footed salamanders (Plethodontidae: Bolitoglossa) from the Costa Rica-Panamá border region.'' Zootaxa, 1981, 57-68.
Wake, D. B. (1991). ''Homoplasy: the result of natural selection, or evidence of design limitations?'' American Naturalist, 138, 543-567.
Written by Catherine Aguilar (catherineaguilar AT berkeley.edu), UC Berkeley
First submitted 2009-02-18
Edited by Kellie Whittaker, Michelle Koo (2018-02-24)
Species Account Citation: AmphibiaWeb 2018 Bolitoglossa pygmaea: Pygmy Web-footed Salamander <http://amphibiaweb.org/species/7248> University of California, Berkeley, CA, USA. Accessed Dec 7, 2019.
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Citation: AmphibiaWeb. 2019. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 7 Dec 2019.
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