Description
This species was described from a single adult male holotype specimen and a single adult female paratype specimen, with a snout-to-vent length of 57.5 millimeters in the male, and 62.9 millimeters. It has small nostrils that are located right at the snout tip, and nasolabial grooves which run from the end of the nostrils to the lip. There are swollen projections on its lips. It has non-prominent eyes which are not visible when viewed from the underside. There is a noticeable groove right beneath the eye, and a less visible groove behind the eye that runs down along the length of the body before turning abruptly downwards to connect with its throat. It has a small mental gland (which are only present in male salamanders), and no other glands on its body. It has 18 costal grooves on each side of its body, and a stout tail that is rectangular and not very constricted at the base. Its limbs are short. It has completely fused fingers, and the toes are fused between digits 1 – 2 and 4 – 5. Digit 3 on its feet projects out prominently and its tip is rounded. The relative lengths of digits on its arms are as follows, from longest to shortest: 3 > 2 > 4 > 1. The relative lengths of digits on its legs are as follows, from longest to shortest: 3 > 4 > 2 > 5 > 1. Smally fleshy projections are found on its cloaca (McCranie 2006).

Oedipina tomasi lacks pale brown and white patches on its head and body that are present in O. elongata. Additionally, O. tomasi has numerous maxillary teeth, unlike in O. elongata, which has none. Oedipina tomasi has a dark black body with pale flecks as opposed to the browner body and absence of flecking in O. gephyra, and is larger in size. One segment of its longest toe is unwebbed, in contrast to the full webbing with only one toe tip protruding in O. gephyra. Oedipina tomasi has distinct digital grooves and transverse grooves at the proximal edges of digits, unlike O. petiola, whose digital grooves are less pronounced, and lacks proximal grooves altogether (Brame 1968, McCranie and Townsend 2011).

In life, the iris, as well as the dorsal and ventral areas of the body and tail, are dark black. The area between and below the nasolabial grooves is light brown and has brown marks. The top of the head is blackish gray, the underside of the head is black, and the dorsal edges of the limbs are dark brown. Pale brown marks are present on the limbs and the underside of the head. White marks are found on the ventral portion of the body. When preserved in alcohol, body color is unchanged one month after collection, except the white marks found on the ventral surface of the body lose visibility, and when viewed under magnification, small pale iridophores become visible (McCranie 2006).

Though only two specimens have been described, it seems that this species is sexually dimorphic in body size, with males being smaller than females. Females have four premaxillary teeth (versus two in males) located in line with 48 maxillary teeth (versus 58), and have cloacal folds, which are absent in males. Females also lack a mental gland lip projections, which are present in males (McCranie 2006).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Honduras

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

It is endemic to the tropical cloud forest in the Cusuco National Park in the Cortés department of northwestern Honduras. Two specimens were found in wet sand underneath decaying vegetation, in Cusuco National Park on banks above the Rio Cusuco. Their habitat is located at 1780 – 1800 meters above sea level, in the Sierra de Omoa mountain range (McCranie 2006, McCranie and Townsend 2011, Castañeda et al. 2008).

Life History, Abundance, Activity, and Special Behaviors
Two specimens were found separately, each on days right after brief rainfall. This species is rare, and no other specimens were recorded over the course of twenty-four collecting days. Oedipina tomasi larvae are listed as terrestrial, but no further reproductive activity or behavior has been recorded (McCranie, 2006, Kolby et al. 2010).

Trends and Threats
Oedipina tomasi populations are decreasing due to the entire species being confined to their single habitat in Cusuco National Park that is continually declining in quality. In the one specimen sampled, there was no evidence of chytrid fungus. (Castañeda et al. 2008, Kolby et al. 2009).

Relation to Humans
N/A

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Subtle changes to necessary specialized habitat
Loss of genetic diversity from small population phenomena

Comments
The species authority is:
McCranie, James R. 2006. New Species of Oedipina (Amphibia: Caudata) from Parque Nacional El Cusuco, Northwestern Honduras. Journal of Herpetology, 40: 291-293.

According to maximum likelihood analysis, O. tomasi forms a clade with sister taxa O. gephyra and O. petiola, most closely related to O. gephyra, as supported by Bootstrap values used to create a Bayesian phylogram. (McCranie and Townsend 2011).

The species name tomasi was chosen to honor James McCranie’s good friend, Tomás Ruiz, who was central to the discovery and collection of the species (McCranie 2006).

Over a course of 24 collecting days, researcher James McCranie collected two specimens (McCranie 2006). One specimen was later checked for chytrid in 2010, and no evidence of the fungus was found (Kolby et al. 2009).

References

Brame, A. H., Jr. (1968). "Systematics and evolution of the Mesoamerican salamander genus Oedipina." Journal of Herpetology, 2, 1-64. [link]

Castaneda, F. 2008. Oedipina tomasi. The IUCN Red List of Threatened Species. Version2014.3. http://www.iucnredlist.org/

Kolby, J. E., Padgett-Flohr, G. E., and Field, R. (2009). ''Amphibian chytrid fungus Batrachochytrium dendrobatidis in Cusuco National Park, Honduras.'' Diseases of Aquatic Organisms, Special Edition 4, preprint 3. Published online May 6, 2009.

McCranie, J. R. 2006. New Species of Oedipina (Amphibia: Caudata) from Parque Nacional El Cusuco, Northwestern Honduras. Journal of Herpetology, 40: 291-293.

McCranie, J. R., Townsend, J. H. 2011. Description of a new species of worm salamander (Caudata, Plethodontidae, Oedipina) in the subgenus Oedopinola from the central portion of the Cordillera Nombre de Dios, Honduras. Zootaxa, 2990: 59-68.

Species Account Citation: AmphibiaWeb 2015 Oedipina tomasi: Tomas' Worm Salamander <https://amphibiaweb.org/species/6815> University of California, Berkeley, CA, USA. Accessed Nov 25, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 25 Nov 2024.

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