The tent tortoise (''Psammobates tentorius'') is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
tortoise
Tortoises ( ) are reptiles of the family Testudinidae of the order Testudines (Latin for "tortoise"). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like o ...
and one of three members of the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
, ''
Psammobates
''Psammobates'' is a genus of tortoise erected by Leopold Fitzinger in 1835. This genus contains three species, all of which are Indigenous (ecology), indigenous to southern Africa. ''.
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(Retrieved 28 February 2010) Known locally as the Karoo tent tortoise, this highly variable species is found in South Africa and
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
.
Distribution
The Karoo tent tortoise occurs at very low densities throughout the
Karoo
The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe Khoemana (also known as !Orakobab or Korana) word is a semidesert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is ...
and other
semi-desert
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of sem ...
areas of southern Africa, extending from central
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
almost to the southern coast of
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
.
Within this range, its population is very sparse and individuals are normally rare and widely separated. The species is also increasingly rare due to
habitat destruction
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
and illegal collecting for the pet trade. Due to its specific diet that consists of certain Karoo plants, this species rarely survives in captivity and usually soon dies when taken outside of its natural
habitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...
.
Identification
The Karoo tent tortoise is a very variable species, with at least three subspecies. Its shell is dark brown or black with a pattern of yellow or orange striped stars radiating from the centre of each domed shield making up the
carapace
A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...
. The tent tortoise has a beautiful geometric pattern of 'Bedouin tents' on its upper shell, and this is appropriate, for it is quite at home in the semi-desert.
The colouring and size of this little tortoise vary greatly, particularly from one area to another, but also within a single 'population'. Occasional specimens are a uniform brown, though this is very rare. Male specimens are much smaller than the females, and have concave bellies.
Although this species shares much of its superficial outer appearance with its relatives in the genus
Psammobates
''Psammobates'' is a genus of tortoise erected by Leopold Fitzinger in 1835. This genus contains three species, all of which are Indigenous (ecology), indigenous to southern Africa. , it can easily be distinguished by its un-serrated shell margins, and the scutes along its shell bridge, which are broader than they are high.
Subspecies
Three
subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
are recognised by biologists:
*Southern ("Karoo") tent tortoise, ''Psammobates tentorius tentorius'' (
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
) or common tent tortoise. Authority: Bell 1828. Distribution: The southern
Karoo
The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe Khoemana (also known as !Orakobab or Korana) word is a semidesert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is ...
region. South Africa(Southern and eastern Karoo from Grahamstown to Matjiesfontein). This subspecies has the most sharply raised 'tents' (conical scutes), with dull yellow stars radiating on a black background.
*Western ("Namaqualand") tent tortoise, ''Psammobates tentorius trimeni''. Authority: Boulenger, 1886. Distribution: The
Namaqualand
Namaqualand ( Khoikhoi: "Nama-kwa" meaning Nama Khoi people's land) is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of . It is divided by the lower course of the Orange River int ...
Coast of Namibia and South Africa (from Lambert's Bay north to beyond the Orange River in Great Namaqualand - extreme western Cape Provinces). This is the smallest subspecies, with the boldest, brightest colouring and well-developed 'tents' (conical shell scutes).
*Northern ("Bushmanland") tent tortoise, ''Psammobates tentorius verroxii''. Authority: Smith, 1839. Distribution: The driest parts of the Karoo inland. Namibia (Northwest to the Great Namaqualand) and South Africa(Northern Cape Province). This subspecies has a flatter, rounder shell with underdeveloped 'tents', and more faded brown colouring.
Behaviour
The female tent tortoise lays a
clutch
A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...
of one to three
eggs
An egg is an organic vessel in which an embryo begins to develop.
Egg, EGG or eggs may also refer to:
Biology
* Egg cell, the female reproductive cell (gamete) in oogamous organisms
Food
* Eggs as food
Places
* Egg, Austria
* Egg, Switzerland ...
, and buries them in the sand as all other tortoises do. The young emerge in late summer or early autumn.
Diet
They depend on a very specialised diet including assorted Karoo bushes,
mesembryanthemum
''Mesembryanthemum'' is a genus of flowering plants in the family Aizoaceae, indigenous to southern Africa. As with many members of that family, it is characterized by long-lasting flower heads. Flowers of ''Mesembryanthemum'' protect their game ...
s and other South African succulents. Due to this diet, this little tortoise does not usually survive in
captivity
Captivity, or being held captive, is a state wherein humans or other animals are confined to a particular space and prevented from leaving or moving freely. An example in humans is imprisonment. Prisoners of war are usually held in captivity by a ...
and usually dies soon, when taken outside of its semi-desert habitat.
Notes
References
* Auerbach,R.D. 1987. The Amphibians and Reptiles of Botswana. Mokwepa Consultants, Botswana, 295 pp.
* Bauer, Aaron M.; Branch, William R. & Haacke, Wulf D. 1993. The herpetofauna of the Kamanjab area and adjacent Damaraland, Namibia. Madoqua (Windhoek), 18 (2): 117–145.
* Duméril, A. M.C., G. BIBRON & A. DUMÉRIL 1854. Erpétologie générale ou Histoire Naturelle complète des Reptiles. Vol. 9. Paris, XX + 440 S.
* Ernst,C.H. and Barbour,R.W. 1989. Turtles of the World. Smithsonian Institution Press, Washington D.C. - London
* Greig, J.C., and P.D. Burdett. 1976. Patterns in the distributions of Southern African terrestrial tortoises (Cryptodira: Testudinidae). Zool. Africana 11(2): 250–267.
* Hughes, B. 1986. Longevity Records of African Captive Amphibians and Reptiles: Part 1: Introduction and Species List 1 - Amphibians and Chelonians Jour. Herp. Ass. Afr. (32): 1–5
* Kuhl,H. 1820. Beiträge zur Zoologie und vergleichenden Anatomie. Hermannsche Buchhandlung, Frankfurt, 152 pp.
* Loveridge, Arthur & Williams, Ernest E. 1957. Revision of the African Tortoises and Turtles of the Suborder Cryptodira. Bulletin of the Museum of Comparative Zoology 115 (6): 163–557
* Smith,A. 1840. Illustrations of the zoology of South Africa, Reptilia. Smith, Elder, and Co., London
* Valverde, J. 2005. Afrikanische Landschildkröten. Reptilia (Münster) 10 (6): 18–25
* Valverde, J. 2005. African Tortoises. Reptilia (GB) (43): 12-20
{{Taxonbar, from=Q2104559
Psammobates
Reptiles described in 1820
Turtles of Africa