Hyloxalus aeruginosus (Duellman 2004)

This is a moderately large species of Hyloxalus; snout–vent length in males measures up to 25.0 mm, in females to 29.2 mm. The discs on the fingers and toes are expanded, half again the width of the penultimate phalange; Finger I is longer than Finger II, and Finger III is not swollen in males. Lateral fringes are present on the fingers and toes. An outer tarsal fold and tarsal tubercle are absent; the inner tarsal fold is curved and distinct on the distal half of the tarsus. Webbing is absent between the toes. Dorsolateral stripes, oblique lateral stripes, and ventrolateral stripes are absent. The dorsum is dull green with a faint bluish tint; bluish cream flecks are present on the flanks. The dorsal surfaces of the digital scutes are white, contrasting with bordering gray surfaces; the throat chest, and anterior part of belly are olive brown with cream spots, and the posterior part of the belly and ventral the surfaces of the thighs are dark yellow. The iris is brown with a cream ring around the pupil. A median lingual process is absent, and the testes are white.

This species is known from two localities at elevations of 1980 and 2180 m along the road from Abra Pardo de Miguel to Moyobamba on the steep east slope of the northern part of the Cordillera Central in northern Peru. The frogs occur along small streams in cloud forest.