Diego A. Ortiz, Caty Frenkel, and Santiago R. Ron, translation by Evan Twomey.
This species is known only from the type locality, at an elevation of 1700 m on the base of Reventador volcano, southwest of the Rio Azuela bridge on the Quito-Lago Agrio road, Sucumbios province, Ecuador (updated from Myers & Daly 1976). Additionally, there are two photographic records from Sucumbios but the specific localities are not mentioned (Lötters et al. 2007).
Habitat and biology
The type locality is a mountainous crest covered in montane forest with a low canopy (15–20 m), with dense tree and bush growth, and vegetation, herbaceous plants, and ferns abundant in the understory. The forest is cool and humid with conspicuous layer of moss and many epiphytes on the tree trunks. The species was found in the day, in or near ground level in leaf litter, in the forest and in cleared surroundings. Eggs are deposited on the ground and tadpoles are transported on the dorsum of adults to bromeliads, where they develop (Myers & Daly 1976).
In males, the average snout-vent length (SVL) is 16.7 mm (range 16.3–17.3; n = 3); in females, the average SVL is 17.6 mm (range 17.3–17.7; n = 4) (Myers & Daly 1976).
Andinobates abditus can be distinguished from other species of dendrobatids in Ecuador based on its color pattern: dark brown with conspicuous orange spots in the armpit and groin (Myers & Daly 1976). The most similar species belong to the genus Excidobates and also inhabit montane forests in the eastern spurs of the Andes. This species can be distinguished from Excidobates condor by its orange spots in the armpits and groin (spots absent in Excidobates condor), and from Excidobates captivus by its dorsal coloration (dark brown in Andinobates abditus vs. black with red flecking or spots in E. captivus).
This species belongs to the genus Andinobates as defined by Brown & Twomey et al. (2011). It presents the following combination of characters (modified from Myers and Daly 1976): (1) discs present on fingers except Finger I; discs expanded to 1.5–2 times the width of the finger; (2) Finger I shorter than Finger II; (3) fingers and toes lack webbing, supernumerary tubercles, and skin fringes; (4) tarsal tubercle usually absent or weakly developed; (5) inner and outer metatarsal tubercles small; (6) skin texture varies between smooth to lightly and moderately granular on the dorsum and venter; (7) males with well-developed vocal sacs; (8) canthus rostralis rounded; loreal region flat or lightly concave and almost vertical; (9) eyes prominent, diameter almost equal to the length of the snout; (10) skin alkaloids belong to the class pumiliotoxin-A.
The body and limb coloration is uniformly dark brown to blackish, except the brilliant orange spots in the superficial posterior of the armpits and groin; the iris is dark brown, indistinguishable from the pupil (Myers & Daly 1976).
This species is listed as Critically Endangered by the IUCN and Critically Endangered by AmphibiaWebEcuador. This species has only been registered from the type locality and has not been observed since 1974. It is probable the species no longer survives in this site due to the forest having been partially destroyed for agriculture and cattle farming. In fact, Bustamante et al. (2005) report its absence from 2000–2003 despite 91 man-hours of searching. It is possible the species occurs in other unsampled sites. It is possible the species has been affected by diseases and climate change.
Taxonomy and evolutionary relationships
Andinobates abditus has not been included in any phylogenies based on molecular information and therefore its evolutionary affinities are speculative. It was originally described as a member of the genus Dendrobates by Myers & Daly (1976). Later, it was transferred to Ranitomeya by Grant et al. (2006) and Andinobates by Brown & Twomey et al. (2011). With Andinobates, A. abditus is contained within the bombetes species group and would occupy the most basal position with respect to the rest of the species in the group (Brown & Twomey et al. 2011). Almendaríz et al. (2014) suggested that A. abditus belongs to the genus Excidobates on the basis of its geographic distribution and morphological characteristics of tadpoles and adults. Frost (2013) provided synonyms and comments on the taxonomy of this species.
The name of this species originates from the Latin abdo meaning remote or secret and refers to the apparent isolation of this high-elevation species with respect to other congeneric species (at the time of description, genus Dendrobates, Myers & Daly 1976).
Myers & Daly (1976) described a live tadpole that was found in a terrestrial bromeliad. Lötters et al. (2007) provided a summary about this species with data on the distribution, habitat, morphology, and biology. In addition, they provided two color photographs of the species in life from Ecuador (Sucumbios province). Bustamante et al. (2005) report information on relative abundance.
Almendáriz, A., Ron, S. R., Brito, J. 2012. Una especie nueva de rana venenosa de altura del género Excidobates (Dendrobatoidea: Dendrobatidae) de la Cordillera del Cóndor. Papéis Avulsos de Zoologia 52:387-399. PDF
Brown, J., Twomey, E., Amézquita, A., Caldwell, J., Barbosa da Souza, M., Lötters, S., Von May, R., Melo-Sampaio, P., Mejia-Vargas, D., Pérez-Peña, P., Pepper, M., Poelman, E., Sanchez-Rodriguez, M., Summers, K. 2011. A taxonomic revision of the Neotropical poison frog genus Ranitomeya (Amphibia: Dendrobatidae). Zootaxa 3083:1-120.
Bustamante, M. R., Ron, S. R., Coloma, L. A. 2005. Cambios en la diversidad en siete comunidades de anuros en los Andes de Ecuador. Biotropica 37:180-189. PDF
Frost, D. R. 2013. Amphibian Species of the World: an online reference. Version 5.6 (15 October, 2012). Base de datos accesible en http://research.amnh.org/vz/herpetology/amphibia/ American Museum of Natural History, New York, USA.
Grant, T., Frost, D. R., Caldwell, J. P., Gagliardo, R. W., Haddad, C. F. B., Kok, P., Means, D. B., Noonan, B. P., Schargel, E., Wheeler, W. C. 2006. Phylogenetic systematics of dart-poison frogs and their relatives (Amphibia: Athesphatanura, Dendrobatidae). Bulletin of the American Museum of Natural History 299:262. PDF
Lötters, S., Jungfer, K., Henkel, F. W. y Schmidt, W. 2007. Poison frogs. Biology, species and captive husbandry. Edition Chimaira, Frankfurt am Main, Germany, 668 pp.
Myers, C. W. y Daly, J. W. 1976. A new species of poison frog (Dendrobates) from Andean Ecuador, including an analysis of its skin toxins. Occasional Papers of the Museum of Natural History, The University of Kansas, Lawrence, Kansas 40148:1-12. PDF