Comprehensive DescriptionRead full entry
In this moderately small species of Hyloxalus males have snout-vent lengths to 24.1 mm and females to 24.8 mm. The discs on the fingers and toes are not or only slightly expanded; Fingers I and II are equal in length, and Finger III is not swollen in males. Lateral fringes are present on the fingers and toes; the outer tarsal fold weak or absent, and the inner tarsal fold is curved on the distal third of the tarsus. The toes are about one-third webbed. The dorsum is pale olive to brown. Dorsolateral stripes and ventrolateral stripes are absent; a pale yellow to tan oblique lateral stripe usually is narrowly bordered by dark brown or black. The gular-chest region is creamy yellow with pair of gray marks; the abdomen varies from dull white to creamy yellow with gray mottling. The iris is grayish brown. A median lingual process is absent, and the testes are white (Edwards 1971).
A tadpole in Stage 34 has a body length of 10.8 mm and a total length of 32.5 mm; the body is ovoid and much wider than high. The snout is bluntly rounded in dorsal view and in profile; the large eyes are situated dorsally, directed dorsolaterally, and not visible from below. The spiracle is sinistral; the tube is short and attached to the body throughout its length. The spiracular opening is directed posterodorsally well below midline at about midlength of the body. The cloacal tube is dextral, short, and attached to ventral fin. The caudal musculature is robust, equal height throughout the proximal one-third of the tail, and gradually diminishes to a pointed tip. The dorsal fin originates on the caudal musculature, is highest at about three-fourths the length of the tail, and gradually diminishes to an acutely rounded tip. The ventral fin originates on the body and is highest at about two thirds the length of the tail. The oral disc is directed anteroventrally. The median half of the anterior labium is bare; elsewhere the labia bear a single row of moderately long, pointed marginal papillae. The labia have shallow lateral folds; submarginal papillae are absent. The jaw sheaths are moderately robust and coarsely serrate; the anterior sheath is in the form of a broad arch, and the posterior sheath is broadly V-shaped. The labial tooth row formula is 2(1)/3; A2 is slightly longer than the other rows. In life, the body is olive gray and the tail is yellow proximally, becoming more orange distally, flecked with gray. In preservative, the dorsum and sides of the body are brown, and the belly is translucent gray; caudal musculature is pale creamy tan with brown flecks, and the caudal musculature is translucent with brown flecks.