Biology:African helmeted turtle

Short description: Species of turtle

African helmeted turtle
Photographed in Uganda
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Pleurodira
Family:	Pelomedusidae
Genus:	Pelomedusa Wagler, 1830
Species:	P. subrufa
Binomial name
Pelomedusa subrufa (Lacépède, 1788)
Synonyms
? Testudo planitia Meuschen, 1778 Testudo subrufa Lacépède, 1788 Testudo galeata Schoepff, 1792 Testudo badia Donndorff, 1798 Testudo rubicunda Suckow, 1798 Emys galeata — Schweigger, 1812 Emys olivacea Schweigger, 1812 Emys subrufa — Schweigger, 1812 Hydraspis galeata — Bell, 1828 Pelomedusa galeata — Wagler, 1830 Pelomedusa subrufa — Wagler, 1830 Chelys (Hydraspis) subrufa — Gray, 1831 Hydraspis subrufa — Gray, 1831 Pentonyx capensis A.M.C. Duméril & Bibron, 1835 Pentonyx galeata — A.M.C. Duméril & Bibron, 1835 Emys (Emys) capensis — Fitzinger, 1835 Hydraspis (Pelomedusa) galeata — Fitzinger, 1835 Hydraspis (Pelomedusa) olivacea — Fitzinger, 1835 Hydraspis (Pelomedusa) planitia — Fitzinger, 1835 Pentonyx gehafie Rüppell, 1835 Pelomedusa gehafiae [sic] Gray, 1844 (ex errore) Pentonyx americana Cornalia, 1849 Pelomedusa mossambicensis W. Peters, 1856 (nomen nudum) Pelomedusa mozambica W. Peters, 1856 (nomen nudum) Pelomedusa nigra Gray, 1863 Pelomedusa gasconi Rochebrune, 1884 Pelomedusa galeata damarensis Hewitt, 1935 Pelomedusa galeata devilliersi Hewitt, 1935 Pelomedusa galeata galeata — Hewitt, 1935 Pelomedusa galeata nigra — Hewitt, 1935 Pelomedusa galeata orangensis Hewitt, 1935 Pelomedusa galeata subrufa — Hewitt, 1935 Pelomedusa galeata gehafie — Parker, 1936 Pelomedusa subrufa subrufa — Mertens, 1937 Pelomedusa subrufa damarensis — Mertens, 1937 Pelomedusa subrufa gehafie — Mertens, 1937 Pelomedusa subrufa wettsteini Mertens, 1937 Pelomedusa subrufa orangensis — Hewitt, 1937 Pelomedusa subrufa olivacea — Loveridge, 1941 Pelomedusa subrufa damaranus [sic] Heck, 1955 (ex errore) Pelomedusa subrufa nigra — Bour, 1986

The African helmeted turtle (Pelomedusa subrufa), also commonly known as the marsh terrapin, the crocodile turtle, or in the pet trade as the African side-necked turtle, is a species of omnivorous side-necked terrapin in the family Pelomedusidae. The species naturally occurs in fresh and stagnant water bodies throughout much of Sub-Saharan Africa, and in southern Yemen.

Description

The marsh terrapin is typically a rather small turtle, with most individuals being less than 20 cm (7.9 in) ranging from 15 to 21 centimeters in straight carapace length, but one has been recorded with a length of 32.5 cm (12.8 in). It has a black or brown carapace. The top of the tail and feet are a grayish brown, while the underside (plastron) is yellowish. The male turtle is distinguished by its long, thick tail. A female tends to have a shorter tail and a broader carapace. A hatchling has a shell size of about 3 cm (1.2 in) in length, and is olive to black in color. It also has two small tubercles under the chin and musk glands in the sides of the carapace. Uniquely, the genus Pelomedusa does not have a hinged plastron (lower shell). All the other species in the family Pelomedusidae, however, do have this feature with which they can, using muscles, close the plastron to the carapace to cover the head and front limbs. Unlike many chelonians, the African helmeted turtle is able, when it finds itself upside down, to right itself with a vigorous flick of its long muscular neck.

Recent genetic research suggests that Pelomedusa comprises at least 10 different species, and not only one as previously thought. In the past the physical differences between populations were not regarded as substantial enough to recognise more than one species.

Geographic range

The geographic range of P. subrufa covers a large portion of Africa, from Cape Town in the south to Sudan in the north and Ghana in the west. It has also been found in Madagascar and Yemen.

Habitat

Its preference seems to be for standing water, such as swamps, pans, dams, and lakes. However it is found to a lesser extent along rivers. It is generally absent from regions that are mountainous, forested, or desert.

Diet

The African helmeted turtle is an omnivorous eater and will eat almost anything mainly involving aquatic invertebrates, small fish, and vegetation. It may feed on carrion. The fine claws on its feet help it tear its prey apart. Hatchlings will eat tadpoles of many frog species, including Phrynomantis microps.

Groups of P. subrufa have been observed capturing and drowning larger prey such as doves that come to drink; the commotion caused by these group attacks is often mistaken for crocodiles. All food is taken underwater to be eaten.

Several large mammals, such as warthogs, Cape buffalo, and rhinoceroses, have recently been documented utilizing the turtles to remove parasites at popular wallowing holes. One such incident in Hluhluwe-iMfolozi park involved two African helmeted turtles removing ticks and blood-sucking flies from the body of a wallowing warthog. Though the turtles probably do not have a symbiotic relationship with these animals, it is very likely that the buffalo, rhinos, and warthogs seek them out and have learned to utilize them from past experiences. This behavior was documented for the first time in the September 2015 issue of Herpetological Review by Andy and Michelle Leighty Jones.

Reproduction

The female will lay two to ten eggs on average, normally during late spring and early summer. The eggs are placed in a flask-shaped nest about 4 to 7 in (10 to 18 cm) deep. The eggs hatch in 75–90 days.

Gallery

• 
  laying eggs
• 
  Juvenile
• 
  adult with head retracted into shell

Further reading

• Boycott, Richard C.; Bourquin, Ortwin (2000). The southern African Tortoise Book – A Guide to southern African Tortoises, Terrapins and Turtles, Revised Expanded Edition. KiwaZulu-Natal: O. Bourquin. 228 pp. ISBN 0-620-26536-1.

Wikidata ☰ Q913795 entry