Description

Diagnosis: Can be distinguished by the following combination of characters: (1) medium size (adults reaching 47.8-51.3 mm SVL in males, 47.7-63.3 mm SVL in females); (2) snout rounded in both dorsal and lateral view; (3) distinct, angular, medially curved canthus rostralis; concave loreal region; (4) low frontoparietal ridges; (5) large rounded (or oval) tympanum; distinct tympanic annulus; well-developed supratympanic fold; (6) in males, vocal sac indistinct, vocal slits lacking; (7) vomerine dentigerous processes are large, angular and located between obliquely oriented choanae; dentigerous processes have 6-14 vomerine teeth each and may be narrowly separated or contacting each other; (8) tuberculate dorsum; (9) small, low tarsal and ulnar tubercles are present; these are slightly larger than the minute dorsal tubercles; (10) no axillary membrane; (11) fingers basally webbed; toes 3/4 webbed; (12) Finger IV with single round distal subarticular tubercle; (13) nuptial excrescences are dark and keratinous and restricted to the prepollex; (14) adult coloration in life: dorsum brown (tan to purplish brown) with a few irregular darker brown markings; pale lip stripe expands to a subocular spot; flanks pale and unmarked; concealed thigh surfaces light brown; throat and belly white; narrow dark stripe along lower jaw; thighs fleshy pink ventrally; bicolored iris with golden upper half, dark dividing stripe, bronze lower half, all with fine dark reticulation; tibia green or white; (15) metamorph coloration in life: light brown dorsum; darker interorbital spot; white upper arms, knees and heels; iris bright orange (Moravec et al. 2009).

Description: Adult males measure 47.8-51.3 mm SVL. Adult females measure 47.7-63.3 mm SVL. Head slightly longer than wide. Snout rounded with distinct medially curved canthus rostralis, concave loreal region and slightly depressed internarial region. Nostrils are slightly protuberant. Eyes are large and quite protuberant. Frontoparietal ridges are present. Large rounded tympanum with distinct annular ring and a well-developed supratympanic fold obscuring the dorsal edge of the tympanum. Vomerine ridges are angular, large and prominent with 6-14 teeth each. Tongue ovoid and widely attached to bottom of mouth. Arms are slender. No axillary membrane is present. Forearm has small low tubercles on the ventrolateral edge. Fingers are basally webbed and have expanded oval discs. Finger III disc width equals about half the diameter of the tympanum. Subarticular tubercles are single, and round. Supernumerary tubercles are present. Palmar tubercle is large and flat. Prepollical tubercle is elliptical and flattened. Legs are moderately long and slender. Heels overlap when limbs are adpressed. Toes are moderately long with oval discs, and are three-fourths webbed. Toe discs are slightly smaller than finger discs. Subarticular tubercles are single, protuberant, and rounded; supernumerary tubercles are also present. Tibiotarsal articulation has small raised tubercles on the outer edge. Posterior surface of proximal third of thigh has rounded tubercles. Ventrolateral edge of foot has small low tubercles. Outer metatarsal tubercle is distinct, round, and small; inner metatarsal tubercle is large and ovoid. Short cloacal sheath present. Vent surrounded by rounded tubercles. Skin on dorsum, head, and dorsal limbs with minute tubercles. Flanks are shagreened. Venter has coarse granulation. Males lack vocal slits and have an indistinct vocal sac. Nuptial pads are dark and keratinous and are confined to the enlarged prepollex (Moravec et al. 2009).

Coloration is pale brown to purplish-brown with occasional irregular dark brown markings. A light narrow stripe runs on the upper lip, expanding into a spot underneath the eye. A dark narrow stripe runs along the lower jaw. Throat and belly are creamy white. Flanks are light colored. Hidden surfaces of thighs are light brown and the undersurfaces of the thighs are fleshy pink. Tibiae are green or white. Iris has fine dark reticulation over a golden upper half, a dark medial stripe, and a bronze lower half (Moravec et al. 2009).

Newly metamorphosed juveniles are light brown with a dark interorbital spot. Bright orange iris. Upper arms, knees and heels are creamy white. (Moravec et al. 2009).

The specific name castaneicola derives from the Spanish word castaña, for Brazil nut tree, and the Latin word colō, meaning "to inhabit" (Moravec et al. 2009).