Phrynobatrachus dendrobates (Boulenger, 1919)
Recent molecular analyses by Zimkus et al. (2010; see Genetics) support the inclusion of P. petropedetoides as a distinct species, following Laurent (1972) and in contradiction to Drewes and Vindum (1994) and Vonesh (2001) who considering it a synonym of this P. dendrobates.
Phrynobatrachus dendrobates is a medium to large species (SVL 27-37 mm) of puddle frog from northeastern Democratic Republic of Congo and southwestern Uganda. Members of this genus are identified by the presence of a midtarsal tubercle, elongate inner metatarsal tubercle, and outer metatarsal tubercle. Phrynobatrachus dendrobates is characterized by a distinct tympanum, digital discs present on the fingers and toes, and moderate webbing with 3 phalanges free on toe IV. Males exhibit well-developed minute spines on the dorsal and lateral surfaces of the body, including the feet.
The IUCN Red List (2009) categorizes this species as Least Concern in view of its relatively wide distribution, its presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category (Drewes and Pickersgill, 2004).
It is present in Virunga National Park in the Democratic Republic of Congo, Bwindi National Park in Uganda, Ruwenzori National Park in Uganda, and Kibale National Park in Uganda (Drewes and Pickersgill, 2004).
There is little information regarding this species, though it is likely to be impacted by loss of habitats for agriculture, livestock, wood extraction and human settlements (Drewes and Pickersgill, 2004)
Populations of this species are decreasing (Drewes and Pickersgill, 2004).
Phrynobatrachus dendrobates is a medium to large sized species (27-37 mm) that is characterized by a distinct tympanum, digital discs present on the fingers and toes, and moderate webbing with 3 phalanges free on toe IV. Males exhibit well-developed minute spines on the dorsal and lateral surfaces, including the feet.
Mitochodrial sequence data from 12S rRNA, valine-tRNA, and 16S rRNA fragment, as well as combined sequence data from mitochondrial and nuclear (RAG-1) genes indicate that P. dendrobates is the sister species of the P. versicolor and P. petropedetoides, and these three species are in turn sister to P. acutirostris (Zimkus, 2010). This group is also hypothesized to include P. dalcqui, P. irangi, and P. sulfureogularis.These large-bodies frogs from the Albertine Rift are sister to P. krefftii from East Africa.
It is most similar to those large species restricted to the Albertine Rift and East Africa, including P. acutirostris, P. asper, P. dalcqui, P. dendrobates, P. krefftii, P. petropedetoides, and P. sulfureogularis. This species is distinguished from P. versicolor by its slim aspect, longer tibia, longer fingers and more developed digits. P. petropedetoides has a blunter snount when compared to P. dendrobates, and males exhibit minute spines only on the feet.
Aspect is slim. This species has an obtusely pointed snout; the snout tip protrudes further than the lower jaw, and its length is slightly more than the diameter of the eye. The head is as long as it is broad. A small conical papilla is present in the middle of the tongue. Canthus rostralis is marked well or only slightly angular; the loreal renal region is folded almost vertically and very concave. The nostril is slightly closer to the tip of snout than to the eye. Interorbital space is slightly wider than upper eyelid. Tympanum is distinct, measuring two-thirds the diameter of the eye. Fingers are rather elongated and dilated at their ends into distinct discs, with the largest disc measuring close to the double the diameter of the finger at its base. The first finger is shorter than the second. The sub-articular tubercles are moderately large and slightly projecting. The tibiotarsal articulation reaches the tip of the nose or between the tip of the nose and the eye when the hind limb is extended. The heels overlap greatly when the limb is bent at right angles to the body. The tibia is 4-5 times as long as it is wide. The tibia is 37.5%-57.1% the SVL (Boulenger, 1919), or the SVL is 1.75-1.84 times the SVL (de Witte, 1941). Digital discs on the toes are slightly smaller than those of fingers. Webbing is moderate with toes 1/3 webbed (Boulenger, 1919); de Witte (1941) notes that the webbing hardly exceeds the metatarsals, but is present as a fringe all the way to the discs. Zimkus (unpublished) found that specimens examined had 3 phalanges free of web on toe IV. Sub-articular tubercles are moderately large and slightly projecting. Small, ovular internal metatarsal tubecles and small, round external metatarsal tubercle. A small tarsal tubercle, not very projecting, is connected to the inner metatarsal tubercle by a fold. The skin is more or less finely granular with many prominent glandular folds. Dorsolateral glandular cords start behind the upper eyelid and extend, more or less continuously, into the area scapular where they meet. A second glandular fold extends from the area behind the eye over the tympanum until the forelimb insertion point. Ventral side is smooth, except at the rear of the abdomen and the thighs, which are covered with large flat granules. In some individuals, there exists a median furrow, more or less marked, extending from the sternal area until the pubic region. Male have an internal vocal sacs, and well-developed minute spines on the dorsal and lateral surfaces, including the feet. De Witte (1941) reports that the spiny tubercles are present on the internal side of digits I, II, III, and IV, and both the internal and external sides of digit V. According to Boulenger (1919) males have spiny, white tubercles on the outer edges of toes IV and V, and toe III to a lesser degree. Zimkus (unpublished) found that males exhibit these spines on either sides of digits, and the entire venter of the foot and tarsus.
Dorsum is dark brown or dark green, mottled with brownish red and brown dark. A yellow bar is present between the eyes. The dorsolateral glandular cords are often bordered in brown dark. The forelimbs and hinds limbs are brownish, finely mottled with brownish red, creating transverse bars. Sometimes a thin dorsal line is present, extending from the snout to the vent. Venter is purplish in color. The throat and the thorax are very dark in color and vermiculated or mottled with white. Belly and hind limbs are mottled or marbled with a purplish colour. A more or less defined white line of extends from the center of the throat to the pubic region. Lower lip is dark purple, finely mottled with a whitish color. A supralabial white lip is often present.
De Witte (1941) records snout-vent lengths of males that are between 27-35 mm (N=9) and females between 31-37 (N=7). The male type specimen measures 32 mm (Boulenger, 1919).
According to Laurent (1972) P. dendrobates and P. petropedetoides are forest-adapted species, but the former lives at lower altitudes (600-1500 m) in or close to marshes in Kivu, while P. petropedetoides is found at slightly higher elevations (700-2300 m) and is more frequently associated with torrents.
It is known to occur at least in the Ituri Forest at Medje (northeastern Democratic Republic of Congo) and Kibale and Bwindi Impenetrable Forests (southwestern Uganda). Records from western Tanzania require verification (Drewes and Pickersgill, 2004).
It lives both in leaf-litter and beside streams in montane forest, occurring between 800 and 1,800m asl., and it appears to be a species confined to the interior of forest (Drewes and Pickersgill, 2004).
It is very poorly known; it appears to be an uncommon species in Kibale Forest, but more common in the Bwindi Impenetrable Forest (Drewes and Pickersgill, 2004).
It lays its eggs off of the ground, usually in tree holes, often above streams, and the parents guard the eggs (Drewes and Pickersgill, 2004).