Description

Diagnosis: This is a toad of medium to large size, with adults having smooth dorsal skin and juveniles having granular skin. The body is compact and sturdy. The loreal region is straight. The tympanum is distinct and teardrop-shaped and its diameter is less than that of the eye. Parotid glands are prominent and broad, with rounded posterior tips; gland width is nearly the same from anterior to posterior. The eyelid is triangular in lateral view and slightly triangular in dorsal view. The extremities are slender in comparison to the body shape. A pair of dark spots is present on the posterior dorsum and the anterior and posterior dorsum bear different coloration (light anterior, somewhat darker posterior). This species can be distinguished from all other members of the clade Amietophrynus by the combination of large size, smooth dorsal skin (in adults), and straight loreal region. B. channingi can be distinguished from other members of the Bufo (Amietophrynus) superciliaris species complex, by having brownish flank coloration (vs. intense reddish to reddish-purple flank coloration inB. s. superciliaris, or red to dark purple or purple-brownish flank coloration in B. s. chevalieri), the combination of a triangular eyelid process plus a broad parotid gland with rounded posterior tip (vs. triangular eyelid process plus a slender parotid gland with pointed posterior tip in B. s. superciliaris, or a rounded eyelid process plus a broad parotid gland with rounded posterior tip in B. s. chevalieri), the combination of paired posterior dorsal dark spots in addition to darker posterior dorsal coloration (vs. only having paired spots in B. s. superciliaris, or only darker posterior dorsal coloration in B. s. chevalieri).

Description: A medium to large compact toad with male snout-urostyle length (SUL) of 106.7–111.8 mm, and female SUL 100.3–143.0 mm. Snout in profile is short, nearly truncate; canthus rostralis is distinct and angular, while the loreal region is slightly concave. Eyelid has a weak triangular process in adults. Tympanum is relatively distinct and tear-drop shaped (vertically oriented), smaller in horizontal diameter than the diameter of the eye, and positioned in a concavity on the cheek. Parotid glands are bulging and elongated, and rounded at the posterior tip. Paired dorsolateral folds extend from posterior to the parotid glands to the groin area. Fingers and toes are simple, with simple subarticular tubercles. Fingers are unwebbed, with relative finger length III>I>II>=IV. Toes have rudimentary webbing, with relative toe length IV>III>V>II>I. No tarsal fold is present. The inner metatarsal tubercle is prominent and oval-shaped; the outer metatarsal tubercle is rounded and indistinct. The dorsum is smooth in adults but granular in juveniles, and juveniles also appear to lack eyelid processes. Males have large dark nuptial pads on fingers I and II, as well as tiny scattered spines on the lateral surfaces of the head and the flanks below the parotid glands and on the anterior and dorsal upper arm surfaces.

In life, the dorsum is a dirty yellowish brown from the snout to the posterior part of the dorsum. The posterior part of the dorsum has paired dark spots and a dark triangular pattern. A dark V-shaped pattern is present on the head and covering the eyelids, and usually a vertebral stripe extends posteriorly from the V. Loreal area, lower parotids, and flanks are brown. The lateral coloration is darker above, almost black. The posterior-most part of the flanks is orange-brown. Forearms are light purple-gray above and dark below, with a white line usually separating the two areas. Inguinal region has small dark spots. Upper hind limbs and feet bear transverse black bars. Throat and venter are pale yellow. Juveniles may be a uniform brownish-black (Orts 1970) or similar to adults but with an interorbital V-pattern; in juveniles, there may be additional pairs of spots on the dorsum, and additional transverse bars on the tibiofibula.

The tadpole has an oval body in early stages, when viewed from above; in later stages the body is more elongated and slightly flattened. Tail is slender, with tail length being 1.33-1.75x body length, and about the same height as the body, including dorsal and ventral fins; the tail tip is rounded. Eyes are dorsal but shift to being more lateral as the tadpole matures. Spiracle is at midbody. Mouth is ventral and has robust lips. The dorsal surfaces are gray and the venter is creamy white and translucent. Keratodont formula after Gosner stage 25 is 1:1+1/3 (tadpole length>13 mm). Newly metamorphosed individuals measure 9-10 mm from snout-vent (Orts 1970).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Congo, the Democratic Republic of the

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

This species is known from the eastern Lower Guinean rainforest in the Democratic Republic of Congo (Boulenger 1919; Wheeler 1922; Noble 1924; Loveridge 1936; Orts 1970; Barej et al. 2011). It may occur more widely, in western Uganda, Rwanda, and Burundi, but this has not been confirmed (Barej et al. 2011).

Life History, Abundance, Activity, and Special Behaviors
It is nocturnal (Orts 1970) and is commonly seen on the forest floor during the rainy season (Noble 1924). It feigns death when disturbed, dropping its head to the ground and lowering its upper eyelids (Noble 1924). The diet has been reported to consist of a variety of invertebrates (Noble 1924), possibly including snails; at the Irangi research station it was frequently found in pits dug to raise snails for human consumption (Barej et al. 2011). Cannnibalism has been recorded in captivity (Orts 1970). Breeding may occur throughout most of the year (Noble 1924). Clutches are large compared to other forest toads, with up to 4500 eggs; each egg measures 1.40-1.95 mm (Noble 1924; Barej et al. 2011). Tadpoles were observed in puddles of about 1 m in diameter in mid-April, with these puddles near small streams that might grow into larger streams after rain and wash tadpoles away (Orts 1970). Tadpoles of 10 mm were also recorded by Orts (1970) in Irangi, DRC, at the end of the rainy season in mid-June; one small vegetation-covered puddle of 40x25 cm (depth 7 cm) was noted to contain over 3000 tadpoles.

Trends and Threats
According to Berej et al. (2011), population size and trends are unknown. This toad has been found in fewer than 15 localities in the eastern Democratic Republic of Congo. Some of these localities are historical (especially those mentioned in Noble 1924 and Loveridge 1936) and may no longer provide suitable habitat. It may require pristine forest. Although Berej et al. (2011) believe that this species may be of "Least Concern" relative to other amphibians, it is potentially threatened by habitat loss due to logging.

Relation to Humans
Noble (1924) noted that locals thought this toad's white secretions might induce blindness, and thus feared it.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities

Comments
The specific epithet channingi honors Prof. Dr. Alan Channing for his extensive research on African amphibians (Barej et al. 2011).

Bufo (Amietophrynus) channingi is part of the Bufo (Amietophrynus) superciliaris species complex, which currently includes B. s. superciliaris (western Lower Guinea), B. s. chevalieri (Upper Guinea), and B. channingi (eastern Lower Guinea).

References

Barej, M. F., Schmitz, A., Menegon, M., Hillers, A., Hinkel, H., Böhme, W., and Rödel, M.-O. (2011). ''Dusted off—the African Amietophrynus superciliaris-species complex of giant toads.'' Zootaxa, 2772, 1-32.

Boulenger, G. A. (1919). ''Batraciens et reptiles recueillis par le Dr. C. Christy au Congo Belge dans les districts de Stanleyville, Haut-Uele et Ituri en 1912-1914.'' Revue de Zoologie Africaine, 1919, 1-29.

Loveridge, A. (1936). ''African reptiles and amphibians in Field Museum of Natural History.'' Zoological Series of Field Museum of Natural History, 22, 1-111.

Noble, G.K. (1924). ''Article II. Contributions to the herpetology of the Belgian Congo based on the collection of the American Museum Congo Expedition, 1909-1915, Part III. Amphibia.'' Bulletin of the American Museum of Natural History, 49, 147-347.

Orts, S. G. (1970). ''Description et écologie des formes larvaires de Bufo superciliaris Blgr (Amphibia, Bufonidae).'' Revue de Zoologie et de Botanique Africaines, 81, 207-219.

Wheeler, W. M. (1922). ''Chpt. II. The ants collection by the American Museum Congo Expedition. In: Wheeler, W.M. (Ed.) Ants of the American museum Congo Expedition. A contribution to the myrmecology of Africa.'' Bulletin of the American Museum of Natural History, 45, 39-269.

Species Account Citation: AmphibiaWeb 2020 Sclerophrys channingi <https://amphibiaweb.org/species/7630> University of California, Berkeley, CA, USA. Accessed Nov 24, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Nov 2024.

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