Gray's stream frog (''Strongylopus grayii'') is a fairly small species of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

in the family

Pyxicephalidae The Pyxicephalidae are a family of frogs currently found in sub-Saharan Africa. However, in the Eocene, the taxon '' Thaumastosaurus'' lived in Europe. Classification The Pyxicephalidae contain two subfamilies, with a total of 12 genera. This f ...

.Du Preez, L. H.; Carruthers, Vincent. ''A Complete Guide to the Frogs of Southern Africa''. Cape Town, South Africa: Struik Nature. 2009Carruthers, Vincent. ''Frogs and Frogging in Southern Africa''. Struik Nature. 2001. , It is a ground dweller, living mainly in vegetation such as sedges, generally brown, slenderly built and agile, with long, practically unwebbed toes.

Description

''Strongylopus grayii'' is a fairly small species (snout-to-vent length of breeding specimens about 25 to 50 mm). The snout is not as pointed as most of the genus, the snout profile being rather reminiscent of the Cape river frog. The ventral skin is smooth, pale to white, the dorsal skin colour is variable, generally shades of brown with darker blotches. Similar blotches form bars across the upper surfaces of the thighs. Often it has a vertebral line in a lightly contrasting colour, pale to reddish. Some colour variants have a broad russet band down the back. The dorsal skin is textured with scattered small, raised ridges, largely longitudinal. The tympanum is smaller in diameter than the eye, but more than half the diameter. Though clearly visible, it is inconspicuous, being situated in a dark facial band of pigment behind the eye. The facial band extends more or less from the nostril, across the lower part of the eye, rearward over the tympanum, to the base of the fore leg. From below the eye, a pale line runs below the facial band to the shoulder. Above the band a light line runs from the snout, across the eye, above the pupil, rearward to the shoulder.

Sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

is slight, with the male having golden coloration on the lower jaw. The toes are well developed and unwebbed, or nearly so, on all four feet. The front toes are slim and roughly as long as the fore legs are thick. The rear toes are long, with the longest (fourth) toe extending forward roughly as far as the front toes when the frog is squatting.

Range and habitat

The species occurs in

Lesotho Lesotho ( ), officially the Kingdom of Lesotho, is a country landlocked country, landlocked as an Enclave and exclave, enclave in South Africa. It is situated in the Maloti Mountains and contains the Thabana Ntlenyana, highest mountains in Sou ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

Eswatini Eswatini ( ; ss, eSwatini ), officially the Kingdom of Eswatini and formerly named Swaziland ( ; officially renamed in 2018), is a landlocked country in Southern Africa. It is bordered by Mozambique to its northeast and South Africa to its no ...

, and possibly

Botswana Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label=Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kalahar ...

and parts of

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

. It has an introduced population on the remote Atlantic island of

Saint Helena Saint Helena () is a British overseas territory located in the South Atlantic Ocean. It is a remote volcanic tropical island west of the coast of south-western Africa, and east of Rio de Janeiro in South America. It is one of three constitu ...

. It is a common species. Gray's stream frog occurs in a wide range of habitats, being only absent from arid areas: it is found in forests, fynbos heathland, thickets, savanna and grassland, as well as modified habitats. Breeding takes place in almost any shallow vegetated body of water.

Habits

Gray's stream frog is locally common where conditions are favourable, such as among grassy or scrubby vegetation around streams and dams, or where there is seasonal water such as roadside ponds or

vlei A vlei () is a shallow minor lake, mostly of a seasonal or intermittent nature. It even might refer to seasonal ponds or marshy patches where frogs and similar marsh dwellers breed. Commonly, vleis vary in their extent, or even in the presence ...

s. In the breeding season, its voice is an inoffensive musical click, rather like a drop of water falling into a pond, but when a large chorus is active, such as in sedge around a dam, the effect is like a loud, continuous rattle. Though the males mainly sing in chorus at night, they may call at any time of the day from concealment, particularly in cloudy weather. Like most frogs, the species breeds in standing water and the adults take to the water if alarmed. They can swim rapidly and with agility, but if they are unable to leave the water, they die within a few hours. Rather than simple drowning, the cause of death seems be absorption of too much water through the skin.

References

{{Taxonbar, from=Q2245923 Strongylopus Amphibians described in 1849 Amphibians of South Africa Vertebrates of Lesotho Vertebrates of Eswatini Frogs of Africa Taxonomy articles created by Polbot