Parhoplophryne usambarica Barbour and Loveridge, 1928
This species is named for the type locality: the East Usambara Mountains of Tanzania.
This monotypic species is known only from the East Usambara Mountains of Tanzania and has not been seen since the 1920’s. It is very similar to the three-fingered or blue-bellied frogs (genus Hoplophryne), but these have a reduced first finger and spines in the males.
A small stout frog. The dorsum is gray-blue with a black stripe that runs from the snout to the eye, along the side and upper leg ending at the knee. The ventral surface is black with blue and white vermiculations. Toes lack webbing and toe tips are not expanded. The legs are barred. Males have blue glands on the arms and chest (Harper et al., 2010).
According to Channing and Howell (2006), tadpoles originally described as Parhoplophryne usambarica by Barbour and Loveridge (1928) were subsequently identified as Hoplophryne rogersi.
Parhoplophryne usambarica is similar to Hoplophryne, but the latter has a reduced first finger and spines in males (Harper et al., 2010). Barbour and Loveridge (1928) note that the color in life P. usambarica is almost identical to H. rogersi, but the snout is more pointed than in H. rogersi.
Habit is moderately stout. Head is small; mouth is rather small, extending backwards a little beyond an imaginary vertical line from the middle of the eye. Interorbital space is twice the width of the upper eyelid. First finger is shorter than the second, which is half the length of the third and slightly shorter than the fourth. Webbing is absent on the hands, and digit tips are not dilated. Well-developed subarticular tubercles are present beneath the fingers and toes. Toes are entirely free of webbing. First toe is very small, about half the length of second, and second is more than half the length of the third, which projects beyond the fifth. The forth being by far the longest. Toes tips are not expanded. A strongly developed, rounded, almost spade-like, inner metatarsal tubercle is present, and almost equally strong outer tubercle, measuring two-thirds the length of the inner metatarsal tubercle, is present. Hind limbs are rather short. The tibiotarsal articulation barely reaches the axilla when adpressed. Skin is perfectly smooth above and below without trace of spinosities; however, is is covered with many short rugose folds (Barbour and Loveridge, 1928).
In life, the dorsum of this species is slate blue, shading to blue-grey peripherally. A black band commences at the tip of snout, bounds the upper lip, envelops eye, passes over forelimb and broadens out on the side, narrows again at hind limb and terminates on thigh at knee. The following transverse black bans are present: two on the thighs, two on the tibia, one on tibio-tarsal articulation and two on foot. The rest of the upper surface of the limbs are blue-grey. Venter is black, vermiculated with white that is slightly tinged with blue. The ground colour of the forelimbs and thighs are brown rather than black. The glands on forearm and breast of males are blue (Barbour and Loveridge, 1928).
In alcohol, the dorsum is purplish-grey, and flanks are darker. Dark purplish blotches are present on a greyish ground of the fore and hind limbs and digits. A white bar is present from the eye to base of fore limb. Venter is white, blotched and spotted with dark brown (Barbour and Loveridge, 1928).
According to Channing and Howell (2006), females reach 23 mm in length; Harper et al. (2010) report that males also reach 23 mm (Harper et al., 2010). The female holotype measured 23 mm (Barbour and Loveridge, 1928).