AMPHIBIAWEB
Bolitoglossa diminuta

Subgenus: Eladinea
family: Plethodontidae
subfamily: Hemidactyliinae

© 2010 David Wake (1 of 4)
Conservation Status (definitions)
IUCN (Red List) Status Vulnerable (VU)
CITES No CITES Listing
Other International Status None
National Status None
Regional Status None

 

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Description
This salamander is one of the smallest known in the genus Bolitoglossa; it has moderate webbing, protuberant eyes, a light mid-dorsal marking that is broad with scalloped edges, and a light venter. The total length is 66 mm and the female standard length is 31-32 mm (from the two known adult specimens: Bolaños and Wake 1981). The tail is moderately long (53% of the total body length) and has a weak constriction at the base. The tail does not show strong lateral compression. Leg length is 22% of the standard length. The head width is 15% of the standard length. Eyes are large and protuberant. There is a deep groove below the eye, following its curvature, and a postorbital groove that becomes continuous with the dorsolateral bands. No interorbital crest is present. The snout is moderately short with a weakly developed canthus rostralis, and the nostrils are small; no labial protuberances are present in the female holotype. Three maxillary teeth and twelve vomerine teeth are present. There are two costal folds between adpressed limbs. Digits are moderately webbed (about 2/3 webbed) except for the inner digit of hands and feet, which is completely webbed. The subterminal pads are weakly defined. Relative finger lengths are 3>4>2>1 and relative toe lengths are 3>2=4>5>1. No postiliac gland is present (Robinson 1976).

In preservative, this species has a brown dorsum with a broad midlateral light field that has scalloped edges, especially around the costal grooves, and darker flanks (Robinson 1976; Savage 2002). There may be darker lateral broad bands that pass above the forelimb insertion sites, becoming indistinguishable from the ground color once they pass over the hind limb insertion sites (Robinson 1976). Elbows and knees are not pigmented (Robinson 1976). The venter is lighter colored with scattered melanophores (Savage 2002). Ventral melanophores are dense in the cloacal region but sparse on the tip of the tail (Robinson 1976).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Costa Rica

 

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It is found in premontane rainforest at Quebrada Valverde, a steep stream near Tapantí, Cartago Province on the Atlantic slope of Costa Rica in the Cordillera de Talamanca, at an elevation of 1555 m asl. The coordinates of the stream are 9' 43' 18"N latitude and 83° 41' 48"W longitude. The female holotype was found on a mat of liverworts on a small branch on the ground, assumed to have recently fallen from a tree. Also found in the liverwort mat were 7 eggs, 5 of which eventually hatched into salamanders of the same species (Robinson 1976).

Life History, Abundance, Activity, and Special Behaviors
It is assumed to be a canopy dweller. Eggs were found in a liverwort mat on a tree branch on the ground, associated with an adult female. Hatchlings measured 8 mm in snout-vent length and 3.2 mm in tail length. It is a direct developer, like others in the genus Bolitoglossa (Robinson 1976).

Trends and Threats
It is a rare species (Savage 2002), known only from two adult specimens plus clutches, but the population trend appears to be stable (Bolaños et al. 2008). No major threats are currently known, but because of its small range, it is at risk for extinction due to stochastic processes (Bolaños et al. 2008). It is not found in degraded environments (Bolaños et al. 2008).

Comments

The specific epithet diminuta means "exceedingly small" in Spanish (Robinson 1976).

This species was assigned to the genus Bolitoglossa due to the presence of 13 costal grooves and the absence of a sublingual fold (Robinson 1976). It can immediately be distinguished from other Costa Rican species due to its small size (in standard length measurement) (Robinson 1976). It is the smallest in the genus (Savage 2002). It is similar to Bolitoglossa gracilis, which has a yellowish ground color with irregular dark brown lines (Savage 2002). It also has a dark longitudinal stripe midventrally (Savage 2002).

A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).

References

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.

Bolaños, F., Wake, D., and Savage, J. 2008. Bolitoglossa diminuta. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. www.iucnredlist.org. Downloaded on 04 December 2009.

Robinson, D. C. (1976). ''A new dwarf salamander of the genus Bolitoglossa (Plethodontidae) from Costa Rica.'' Proceedings of the Biological Society of Washington, 89(22), 289-294.

Savage, J. M. (2002). The Amphibians and Reptiles of Costa Rica. The University of Chicago Press, Chicago and London.



Written by Mae Huo (mxhuo AT berkeley.edu), University of California, Berkeley
First submitted 2009-11-02
Edited by Kellie Whittaker (2010-04-09)

Species Account Citation: AmphibiaWeb 2010 Bolitoglossa diminuta <http://amphibiaweb.org/species/3969> University of California, Berkeley, CA, USA. Accessed Oct 20, 2017.



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Citation: AmphibiaWeb. 2017. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Oct 2017.

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