AMPHIBIAWEB
Schismaderma carens
Red Toad
family: Bufonidae

© 2011 Martin Pickersgill (1 of 26)
Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
CITES No CITES Listing
Other International Status Least concern (IUCN)
National Status None
Regional Status None

 

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From the Encyclopedia of Life account:

Distribution

S. carens occurs from southeastern Democratic Republic of Congo and Tanzania, southward to Botswana, Zimbabwe, Mozambique, South Africa, and Swaziland (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Minter, L.R. and Thern, J.
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

The following is from the original description by Smith (1848):

BUFO CARENS.-SUNDERWALL.
REPTILIA.-PLATE LXVIII. FIG. 1.
B. supeme, subgranulosus ; lateribus plica longitudinale verrucisque magnis rugosis ; glandulis parotideis nullis; extremitatibus poaterioribus exteme verrucosis; dorso maculis circularibus duabus verido-nigris notato; extremitatibus parae fasciis subnigris variegntis.
COLOUR.-The upper surface of the head anteriorly, the eye-shields, and the sides of the head intermediate between oil-green and ochre-yellow; the ground colour of the hind-head, the back, the upper portion of the sides, and the outer surface of the hinder legs, light blackish green, freckled with ochre-yellow or yellowish brown, the warts or granulations on the surface being the one or otber of these colours; many of the larger warts have a small reddish orange spot at or about their centre. Besides these variegations, the back is also marked with two circular spots of a greenish black colour, about a line and a half in diameter, one on each side of the vertebral line and situated about the commencement of the last third of the back. The fore-legs are crossed by two bars of the same colour as the spots of the back, and at the commencement of the tarsus there is also an irregular indistinct blotch of the same hue. The upper surface of the tarsi, and the outer surface of the forelegs dull oil-green, the second joint of latter variegated with two transverse greenish black bars, and the upper surface of the feet sparingly freckled or clouded with a lighter tint of the same colour; tubercles of the under surface of the feet and toes sienna-yellow. The cuticular fold which extends along each side of the body, the inner snrface of the extremities, and all the under parts, intermediate between ochre-yellow and yellowish brown; the fold is edged above by a narrow, irregular greenish line which commences at the tympanum and terminates a little in front of the base of the hinder extremities. Tympanum pale greyish brown, tinged with green. The iris appears to have been greyish green with a metallic lustre.

FORM, &c.-Figure moderately robust; head short, broad posteriorly, anterior to eyes rather narrow, the nose truncate and nearly vertical; nostril ovate, one at each angle of the muzzle, the opening directed outwards and back wards. Eye-shields convex and raised; tympanum large, nearly circular, close to the eye, its upper margin almost in contact with the outer canthus; parotid glands wanting. When the fore-legs are placed along the sides of the body, the point of inner toe reaches to the base of the hinder legs, the first or outer toe is a little longer than the third or fourth, which are nearly of equal length, the second a little longer than the first. The hinder extremities when directed along the body, have the second toe projecting beyond the nose. On the under surface of each of the fore-feet, there are two large subovate tubercles and a number of smaller ones between them and the origin of the toes. The under surface of each of the hinder feet has two large oblong tubercles parallel to each other, -one behind the outer, the other behind the inner toe; also, before and behind these, many smaller warts of a roundish form; under each joint of the toes there is also a rounded tubercle. The toes are slightly depressed, rather narrow at the point, and at the base connected by a rudimentary web: the first or outermost, and the third nearly of equal length, the second more than double the length of the first, the fourth considerahly shorter than the third, and the fifth, or innermost, much shorter than the fourth, (vide fig. 1 a). On each side of the body, between the fore and hinder extremities, a raised fold of skin giving cover to a series of small glands. The skin of the head is smooth and closely adherent to the parts underneath, that of the back and fore-legs slightly granular; the sides ahove the cuticular fold, and the outer and hinder surfaces of the posterior extremities studded with large rough depressed warts, the surface of each finely granular; the sides below the fold, and all the under parts rugose from the existence of numerous, small, closely set granulations and irregular wrinkles. The parotid glands are long, rather narrow, and rounded at each extremity, the hinder one rather the broadest. The internal openings of nostrils subovate, one close to each side of the upper jaw. The openings of the Eustachian tubes triangular, and immediately inside of the angles of the mouth. Gape moderately large; upper jaw with a slight notch at its apex for the lodgment of a small protuberance which exists at the point of the lower one. Length of specimen described, from nose to anus 3 inches 3 lines, length of anterior extremities, to point of longest toe, I inch 9 lines ; length of hinder extremities, to point of longest toe, 3 inches 6 lines.

Inhabits the interior of Southern Africa. For the opportunity of describing and figuring this species, I am indebted to the kindness of Professor Sunderwall of Stockholm. It was obtained through the zealous exertions of Mr. Wahlberg, a Swedish naturalist, who visited the districts where it occurs at a more favourable season of the year than I did, and, in consequence, obtained several very interesting reptiles, which were not to be seen as I passed over the country. It differs from the true toads only in not possessing parotid glands, and if this deficiency be found to exist, when the opportunity occurs of examining more individuals of the species, it may be necessary to regard it as the type of a new group. It does not appear to me it could be classed with propriety in any of the groups yet constituted which have as characters, a visible tympanum, and no parotids.


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Size

Frogs are approximately 80 mm in snout-vent length (Harper et al., 2010).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Diagnostic Description

This is a large toad with broad glandular dorsolateral ridges. Dorsal coloration and markings are highly variable, ranging from reddish, gray or brown with darker markings, including spots, triangles or X’s on the dorsum (Text from Harper et al., 2010).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Comparisons

This species is superficially similar to Amietophrynus brauni, but lacks parotid glands (Text from Harper et al., 2010).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Habitat and Ecology

S. carens inhabits a wide variety of vegetation types, primarily in the Savanna biome, but is also found in Grassland vegetation types. This species often enters houses, taking shelter in cupboards, plant pots, drawers and other unexpected places (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).

This species is found in grasslands, shrubland, wooded savanna and disturbed areas, including ranches, agricultural areas and towns. It is common but generally only seen when it is breeding (Text from Harper et al., 2010).


Author: Minter, L.R. and Thern, J.
License: http://creativecommons.org/licenses/by-nc/3.0/

Advertisement Call

The species cannot be confused with any other toad species and has a particularly characteristic call. The low, booming call is produced while floating in water with limbs outstretched. Calling usually occurs at night but also on overcast, humid days. Calling has been recorded October–January (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).

Males call after the start of the long rains (Text from Harper et al., 2010). The call is described by Channing and Howell (2006) as “a very loud, long whoop.”


Author: Minter, L.R. and Thern, J.
License: http://creativecommons.org/licenses/by-nc/3.0/

Reproduction

S. carens breeds in deep, muddy pools or dams in these habitats. Breeding occurs in summer, usually at the peak of the rainy season (Carruthers and Carruthers 1979). Eggs are laid in double strings (cf. Stewart 1967) entwined around submerged vegetation. Estimates of egg numbers vary from about 2,500 to 20,000 (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).

Females lay long double strings of eggs in standing water, often attached to vegetation. Clutches typically contain over 2000 eggs. Eggs and tadpoles develop quickly, often metamorphosing in just over a month (Text from Harper et al., 2010).


Authors: Zimkus, Breda; Minter, L.R. and Thern, J.
License: http://creativecommons.org/licenses/by-nc/3.0/

Tadpole morphology

An interesting feature of the tadpole is the horseshoe-shaped fold of skin that extends backwards from behind the eyes to the middle of the body. This structure has a respiratory function (Charter and MacMurray 1939; Channing 2001). Tadpoles exhibit shoaling behaviour, forming dense clusters, 10–15 cm in diameter (Wager 1965; Pienaar et al. 1976; Passmore and Carruthers 1995). This shoaling behavior does not appear to deter predators as there are many records of fish, terrapins, birds and aquatic insects and their nymphs or larvae feeding avidly on these swarms (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Minter, L.R. and Thern, J.
License: http://creativecommons.org/licenses/by-nc/3.0/

IUCN Red List Category and Justification of Conservation Status

S. carens is not threatened (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Minter, L.R. and Thern, J.
License: http://creativecommons.org/licenses/by-nc/3.0/