Yellowbelly mud turtle  (Pelusios castanoides)

Classified as Least Concern (LC) on the IUCN Red List (1). Subspecies: Seychelles chestnut-bellied mud turtle (P. c. intergularis) is classified as Critically Endangered (CR) on the IUCN Red List (1).

This medium-sized turtle has a long, elongated upper shell (carapace), which is yellowish, olive or black in East African and Madagascan populations, and dark with a marbled pattern of yellow and brown marks in the Seychelles subspecies. The lower shell (plastron) is yellow, as its common name suggests, with a dark border along the seams. The head is brown to olive-black, with a slightly protruding snout, and the legs and tail are yellow to brown. The male has a narrower shell than the female (particularly in the Seychelles chestnut-bellied mud turtle subspecies (P. c. intergularis)) and a longer, thicker tail (2).

Two subspecies are currently recognised. The nominate subspecies, the East African yellow-bellied mud turtle (P. c. castanoides), ranges from Kenya in East Africa south to Swaziland and north-east South Africa, and also occurs on Madagascar (2) (3). The Seychelles chestnut-bellied mud turtle (P. c. intergularis) is endemic to the Seychelles, where it is found on Mahé, Cerf, Praslin, La Digue, Fregate and Silhouette islands (1).

This semi-aquatic turtle is present in rivers, marshes and swamps (1) (2).

The yellowbelly mud turtle feeds mainly on large pulmonate snails and floating water lettuce. The Seychelles chestnut-bellied mud turtle is reportedly nocturnal, and has been recorded eating invertebrates, fish, amphibians, fruit and other plant material (1) (2).

In the Seychelles, there is often fierce competition between males for access to females, with only the stronger individuals successfully managing to breed (1). Here, eggs are laid from December to January (1), while two captives from Malawi each laid 25 eggs at the end of September (2). During the dry season, this species aestivates in the mud (2).

While the East African yellow-bellied mud turtle (P. c. castanoides) is not considered threatened, the Seychelles chestnut-bellied mud turtle (P. c. intergularis) teeters on the brink of extinction, with fewer than 100 adults estimated to remain in the wild in 2002 (1). This subspecies has a restricted and fragmented range on a handful of small islands, and is experiencing ongoing declines as a result of habitat loss and deterioration caused by drainage, pollution (rubbish dumping, sewage and/or pesticide run-off), marsh invasion by water lettuce, and possibly predation (1) (4).

The critically endangered Seychelles subspecies is protected under Seychelles law, and although absent from any formal reserves, the turtle’s range on Fregate and Silhouette are conservation managed areas (1). Effective conservation of this subspecies not only requires protection of its wetland habitats, however, but also the establishment of new populations within protected areas (4). To this end, the Nature Protection Trust of the Seychelles (NTPS) has established a captive breeding programme in which juveniles are reintroduced into secure reserves (4) (5).

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the yellowbelly mud turtle see:

Turtles of the World (CD-ROM), by Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W.:
http://nlbif.eti.uva.nl/bis/turtles.php?selected=beschrijving&menuentry=soorten&id=125

For more information on the Seychelles chestnut-bellied mud turtle and its conservation see:

Gerlach, J. & Canning, L. (2001) Range contractions in the Critically Endangered Seychelles terrapins (Pelusios spp.). Oryx, 35(4): 313 – 321. Available at:
http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-3008.2001.00203.x#search=%22Range%20contractions%20in%20the%20Critically%20Endangered%20Seychelles%20terrapins%22