Comprehensive DescriptionRead full entry
Epipedobates machalilla is a slender frog with snout-vent lengths of 14.4 - 16.0 mm in males and 15.0 - 17.6 mm in females. The snout appears rounded in dorsal view and protruded in profile view. Their head is slightly longer than wide. The nostrils protrude slightly laterally. The tympanum is small and hardly visible. The forelimbs are moderately long with unwebbed fingers. Finger I is longer than finger II, with fringe absent on Finger II. The terminal discs of the fingers appear slightly expanded. The hind limbs appear long and moderately robust. The webbing is vestigial between Toes III and Toes IV. The toes lack lateral fringes and its terminal discs are slightly expanded. The dorsal and ventral surfaces are smooth (Coloma 1995).
Epipedobates machalilla can be distinguished from other species in the genus by its dark coffee-color and its non-venomous nature. Epipedobates machallila appears similar to Hyloxalus breviquartus, H. cevallosi, and Colostethuys fugax, and in that they all have solid, oblique lateral stripes, unmarked bellues, and rudimentary or absent membranes between the digits on the foot. However, E. machallila differs from C. fugax in that it is slightly larger and has an X-shaped mark on the scapular region. Epipedobates machalilla also differs from H. breviquartus and H. cevallosi in that the males have a swollen third digit on the foot (Coloma 1995).
In life, Epipedobates machalilla appears pale olive-tan on its dorsal surfaces, and have a dark brown X marking on the scapular region. The flank is dark brown to black. The upper lip is creamy yellow with pinkish shades. The oblique lateral strip is either creamy yellow or white with pale pinkish permeations projected anteriorly. The arms are pale orange and the dorsal surfaces of the legs are pale brown. The posterior surfaces of the thighs are yellowish orange. There is a discrete orange mark in the groin region. The ventral surfaces are cream color. The iris is gold color (Coloma 1995).
In preservative, the dorsal surfaces appear gray with dark brown marks. The oblique lateral strip is white. Black bands that extend from the tip of the snout to groin appear on the flanks. The upper lip is white. Two white stripes can be seen on the thighs. The posterior surface of the thigh is brown, decorated with small white spots. Transverse brown bars are present on the dorsal surfaces of the fingers (Coloma 1995).
There is significant geographic variation; with some specimens presenting with a narrow middorsal black stripe and in some specimens the white ventrolateral strip is indistinct. Other variants include individuals with small, scattered marks on the throat and individuals with two spots in the mental region (Coloma 1995).
When E. machalilla was first described in 1995, it was included in the Colostehus genus. Taxonomic revisions in 2006 then included the machalilla species in the Epipedobates genus (Coloma 1995).
The subspecies name machalill refers to the Machalilla National Park in which it is found (Coloma 1995).
E. machalilla is used for embryonic development studies (CITES 2013).