Comprehensive DescriptionRead full entry
Diagnosis: Small species of Epipedobates, with males measuring 15.3-16.9 mm SVL, n = 12), females unknown; finger I much longer than II; finger III swollen; basal webbing present on toes II-III-IV; metatarsal fold absent; dorsal skin finely granular; dorsal coloration in life dark green; pale faintly defined oblique lateral stripe; thin ventrolateral stripe and medial longitudinal throat stripe, abdomen mottled with spots and/or dark reticulations (Mueses-Cisneros et al. 2008).
Description: Males measure 15.3-16.9 mm SVL. Head width is 32.5-35.3% of SVL and 88.8-96.5% of head length. Snout tilted and projecting slightly over the lower jaw in lateral view and weakly rounded in dorsal view. Nostrils directed dorsolaterally, not visible dorsally. Tympanum medium-sized, 32.6-47.6% of the diameter of the eye; tympanic ring concealed posterodorsally; tympanic fold absent; canthus rostralis slightly defined; straight to weakly concave loreal region inclined toward the upper lip.Relative length of fingers III>I>II>IV; finger I much longer than finger II (128.3-134.8% of finger II, avg. of 130.8%); finger III swollen; finger IV extends to the middle of the distal subarticular tubercule of finger III (although in some specimens it reaches only to the edge of the distal subarticular tubercule of finger III); palmar tubercle single, large, rounded, and protuberant; thenar tubercle prominent, elongated and located at the outer edge of the base of the thumb; single well-defined subarticular tubercle on fingers I and II and two subarticular tubercles on fingers III and IV, with the distal tubercle poorly defined and less protuberant; fingers lack webbing; supernumerary tubercle absent. Relative length of toes IV>III>V>II>I; toes I-IV bear thin dermal flanges; webbing present on toes II-III-IV, with webbing formula II 2-3.5 III 3-4 IV; inner metatarsal tubercle elongate, about 1.5 to 2 times the size of the rounded outer metatarsal tubercle; supernumerary plantar tubercles absent; subarticular tubercles prominent, one on toes I and II, two on toes III and V, three on toe IV; tarsal keel prominent, curved internally, not extending from the inner metatarsal tubercule. Dorsal skin of head, eyelids, and body is finely granular to smooth, ventral skin smooth to slightly granular. Metatarsal fold absent. Postrictal tubercles absent, cloacal tubercles absent. In males, both testes generally have moderate black pigment, with some specimens having right testis white and left moderately pigmented, and some having both testicles white (Mueses-Cisneros et al. 2008).
Color: Adult males have a dark green dorsum with black flanks, a faint poorly-defined bright green oblique lateral line extending from the groin to halfway up the body, and light green to blue-green ventrolateral line extending from the groin to the lip; axilla and anterior thigh stained with light green; fingertips light green to blue green; venter light green, mottled with spots and/or reticulations; gular region green with medial light stripe and with two black stripes (Mueses-Cisneros et al. 2008).
Coloration in ethanol: dorsum black to dark brown; venter gray to cream with black to dark brown spots and / or rounded reticulations, very thin gray oblique lateral line on the thigh and groin, reaching only up to 1/4 body length, very faint continuous gray ventrolateral line most evident from the upper lip to the axilla, throat with a medial stripe, dark chest spots that may be interconnected (Mueses-Cisneros et al. 2008).
Similar species; E. narinensis shares with E. boulengeri and E. espinosai the presence of a medial longitudinal chin stripe, but can be distinguished by having finger I much longer than finger II (128.3-134.8%, avg. 130.8%), versus finger I slightly longer (110.8%) than finger II in E. boulengeri and E. espinosai. Additionally, E. narinensis can be distinguished from E. boulengeri and E. espinosai by coloration in life and in preservative: in life, E. narinensis is dark green with light green ventrolateral and lateral oblique lines, whereas E. boulengeri is brown to reddish-brown with red, yellow, or white ventrolateral and lateral oblique lines, and E. espinosai is red with a turquoise lateral oblique line, and an interrupted ventrolateral line. Preserved, E. narinensis has a black to dark brown dorsum, with the lateral oblique line faintly visible, and a gray venter mottled with black blotches, while E. boulengeri has a brown dorsum with dark brown flanks, ventrolateral and lateral oblique lines clearly visible, and a cream or white venter with dark spots, and E. espinosai has a brown dorsum and a cream venter with dark brown spots. Although only a very young tadpole was examined (stage 25), It may be possible to distinguish larvae of E. narinensis by differences in the dorsal fin: in E. narinensis the dorsal fin rises after ⅓ the length of the tail, while in E. espinosai the fin occurs at the junction of body and tail.Another species that could potentially be confused with E. narinensis is Ranitomeya viridis, a small green species. However, R. viridis is smaller, has finger I much shorter than finger II, lacks webbing on toes II-III-IV, is metallic green with no pattern of lines, and lacks the medial longitudinal throat stripe (Mueses-Cisneros et al. 2008).
Tadpoles: At stage 25, the total length is 8.2 mm and body length is 3.2 mm, corresponding to 39% of the total length total. Body ovoid and depressed; midbody width 2.2 mm. Snout rounded in dorsal and lateral view. Nares small, circular, directed anterolaterally. Lateral line system not obvious. Posterior supraorbital and loreal lines just noticeable on the right side of the body. Spiracle sinistral, poorly visible, located approximately 56% down body length (from tip of rostrum). Cloacal tube free then directed slightly right. Tail length 5.0 mm, 61% total length, muscle flow tapering gradually to the distal edge; tail width at the junction with the body 0.8 mm, height of caudal musculature at the junction of the tail with the body 1.2 mm; 1.5 mm maximum height; fin of tail rises 1.7 mm from the body (approximately 34% of the tail length), where it rises sharply to the distal part of the tail.Oral disc is located ventrally and is emarginate. Dental formula 2 / 3 (Mueses-Cisneros et al. 2008).
Coloration of the tadpole in formalin: Anterior part of the body dorsally brown with light cream spots; postorbital region to the junction of the tail cream with dark brown blotches, middorsal region of the tail joining with the body is dark brown; intestines cream; light cream ventrally with irregular coffee spots; cream intestinal region, stained with coffee spots laterally; cream tail with dark brown spots that may extend to a lesser degree on the fins; eye black, gray pupil (Mueses-Cisneros et al. 2008).
Species authority: Mueses-Cisneros et al. (2008).
Etymology: The specific name was given as a tribute to the people of Nariño, Colombia (and the type locality in the department of Nariño) (Mueses-Cisneros et al. 2008).