African helmeted turtle

African helmeted turtle
Conservation status
Least Concern (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Pleurodira
Family:	Pelomedusidae
Genus:	Pelomedusa
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 Duméril & Bibron, 1835 Pentonyx galeata 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 Gray, 1844 (ex errore) Pentonyx americana Cornalia, 1849 Pelomedusa mossambicensis Peters, 1856 (nomen nudum) Pelomedusa mozambica 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 Heck, 1955 (ex errore) Pelomedusa subrufa nigra Bour, 1986

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

Description

Side view of a captive specimen, showing claws and lighter underside

The Marsh Terrapin is typically a rather small turtle, with most individuals being less than 20 cm in carapace length, but one has been recorded with a carapace length of 32.5 cm. It has a black or brown carapace (shell). The tops of the tail and limbs are a grayish brown, while the underside 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 1.2 inches 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, Pelomedusa does not have a hinged plastron (lower shell). All the other species in the family Pelomedusidae, however, have this feature which they can, using muscles, close to cover their heads and front limbs. Unlike many chelonians, African helmeted turtles are able, when they find themselves upside down, to right themselves with a vigorous flick from their long muscular necks.

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.

Distribution

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

Life history

Adult specimen running down a lake embankment

Juvenile marsh terrapin

Habitat

They are semiaquatic animals, living in rivers, lakes, and marshes, and they also occupy rain pools and places that are fertilized.

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

Diet

The African helmeted turtle is omnivorous and will eat almost anything. Some of the main items in its diet are insects, small crustaceans, fish, tadpoles, earthworms, snails and vegetation. It may also feed on carrion. The fine claws on its feet help it tear its prey apart.

Groups of these turtles have been observed capturing and drowning larger prey such as doves when they come to drink; the commotion caused by these group attacks are 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.

Seasonal movements

During wet weather these terrapins will often leave their water bodies and embark on long overland journeys. During exceptionally dry weather when their water bodies dry up, they will typically dig themselves into the ground and bury themselves until rains return; they have been known to spend months or even years in such a state. They will also hibernate during very cold weather, and aestivate during unusually hot, dry weather.

Reproduction

Courtship is held year round. The male will follow the female, nodding his head in front of hers. If she is not responsive, she will nip and snap and walk away. If she is willing, she responses by nodding her head or just standing still, so he can sit onto her. While mating both of the turtles shake their head.

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 deep. The eggs hatch in 75– 90 days.

Captivity

African side-necked turtles are popular as a pet because of their unusual head tucking behavior.

References

• Richard C. Boycott and Ortwin Bourquin: The southern African Tortoise Book – A Guide to southern African Tortoises, Terrapins and Turtles, O. Bourqin, KiwaZulu-Natal 2000, ISBN 0-620-26536-1