Description
Rhinatrema ron is a large caecilian, initially described from one individual with a total length of 353 mm (Wilkinson and Gower 2010). A second specimen of unknown sex had a total length of 174 mm (Azevedo et al. 2021). The head is U-shaped, tapering down at about a 45 degree angle at the front of the snout, with a slightly subterminal lower jaw. A bulge due to the jaw adductor muscles can be seen laterally behind the eyes. The eyes are very small, slightly elevated above surrounding skin and are visible through a layer of transparent skin. The tongue is plicated. The tail is short, rounded in shape, and slightly compressed laterally. The vent is irregular and only slightly longitudinal (Wilkinson and Gower 2010). The species has 321 - 328 ventral primary annuli and may have up 347 dorsal primary annuli (Wilkinson and Gower 2010, Azevedo et al. 2021). For more information on their description please see Wilkinson and Gower 2010 and Azevedo et al. 2021.

DIAGNOSIS:

Rhinatrema ron was previously identified as E. lativittatus but can be differentiated based on locality as the latter is only found in “Eastern Peru”. Rhinatrema ron can be differentiated from most other similar species by a larger body size, wider lateral stripe and a heavier pale mottled pattern. The species also has fewer mandibular teeth than other similar species. More specifically, Rhinatrema bivittatum can be differentiated by the pale patch underneath the tail vs the dark patch seen in R. ron (Wilkinson and Gower 2010). Rhinatrema ron can be differentiated from Rhinatrema uaiuai by the former having a paler head color without small yellow spots or stripes between the eye and nostril. Rhinatrema ron can be differentiated from Rhinatrema gilbertogili by the former having a plicated tongue, pigmented palatine mucosa (vs smooth and unpigmented), and having 38 more annuli (Maciel et al. 2018). Both above species were originally incorrectly assumed to be Rhinatrema ron by Maciel et al. (2012). The two species were differentiated from Rhinatrema ron and described by Maciel et al. in 2018.

COLORATION:

The color of the head is mostly beige, mottled with dark irregular blotches. The body is a darker brown lavender color with pale beige/cream mottling on both the dorsal and ventral sides, separated by a thick cream-colored lateral stripe >2mm. The lateral stripe is interrupted with darker speckling just before the head and near the end of the tail. The dark coloring on the ventral side forms a U shape edged by cream coloring at the end of the tail past the vent. The annuli have small pale edges (Wilkinson and Gower 2010).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

Rhinatrema ron is confirmed from two localities: the type locality in Reserva INPA-WWF, Amazonas, Brazil (Wilkinson and Gower 2010), and Nova Colina, Rorainopolis, Brazil, from which it was collected in 2012. The latter specimen was found in a forested campinarana (poor soil) area (Azevedo et al. 2021).

Life History, Abundance, Activity, and Special Behaviors
Rhinatrema ron is rare, only known from two specimens, and thus little is known about its biology (Azevedo et al. 2021).

Trends and Threats
Threats to the species may include habitat alteration, fragmentation, and destruction caused by human activity like pollution, mining, agricultural activity and expansion, urbanization, fires, illegal hunting/capture, and power generation developments. However, with only two specimens known, little is known about the population or distribution (Azevedo et al. 2021).

Comments

PHYLOGENETIC RELATIONSHIPS:

The species description was based on a single museum specimen collected in 1983 and characterized by its large size (Wilkinson and Gower 2010). A second individual was identified in 2021 (Azevedo et al.) and several individuals were incorrectly identified as R. ron and later named as new species (Maciel et al. 2018). However, as of 2022, no phylogenetic study has been conducted with R. ron as a sample.

References

Azevedo, W.d.S., de Oliveira, A. M., Costa, E. R. (2021). "Herpetofauna from two locations in the state of Roraima, Amazon Rainforest, Brazil." Herpetology Notes, 14, 1417-1428. [link]

Maciel, A.O., Sampaio, M.I.C., Hoogmoed, M.S., Schneider, H. (2018). "Description of two new species of Rhinatrema (Amphibia: Gymnophiona) from Brazil and the return of Epicrionops niger to Rhinatrema." South American Journal of Herpetology 13(3), 287–299. [link]

Maciel, A.O., Hoogmoed, M.S., Peloso, P.L. (2012). "Variation in the glossal skeleton arrangement of Rhinatrema ron (Gymnophiona: Rhinatrematidae) and its systematic implications." Salamandra 48(4), 224–226. [link]

Wilkinson, M. Gower, D.J. (2010). "A new species of Rhinatrema Dumeril & Bibron (Amphibia: Gymnophiona: Rhinatrematidae) from Amazonas, Brazil." Zootaxa 2650, 63–68. [link]

Species Account Citation: AmphibiaWeb 2025 Rhinatrema ron: Ron's Rhinatrema <https://amphibiaweb.org/species/7616> University of California, Berkeley, CA, USA. Accessed Apr 19, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Apr 2025.

AmphibiaWeb's policy on data use.