(Siebenrock, 1906a)
Seychelles mud turtle
Recognition
The black carapace (to 16.5 cm) is elongated, oval, broadest at the center, and has a low vertebral keel. Vertebral 1 is flared anteriorly and the 5th is flared posteriorly; the first three and the 5th vertebrals are broader than long, the 4th may be as long as broad. Eight neurals are present; the 7th and 8th are shortened and isolated (Bour, 1983). The posterior marginals are not serrated. The plastron is large, almost covering the entire carapacial opening; its short anterior lobe is less than twice as long as the interabdominal seam. The posterior lobe is only slightly constricted at the level of the abdominal-femoral seams and has a deep posterior notch. The plastral formula is: abd > fem > intergul > hum > an > pect > gul. The pentagon-shaped intergular varies from 1.5 to 2.0 times as long as broad. The bridge is broad and lacks an axillary scute. The plastron either is totally black or may have a small medial area of yellow pigment along the hinge. A slightly protruding snout is present, and the upper jaw may lack toothlike cusps. The seam between the frontal and temporal scales is long. The postocular scale usually touches the masseteric scale; the supralabial scale is usually absent, but, if present, is small. The tympanum is oval in P. seychellensis but round to elliptical with the narrow end anterior in P. castaneus (Bour, 1983). Two chin barbels are present. The head is brown with yellow vermiculations. Both neck and limbs are yellowish brown; there are 8-10 enlarged transverse scales on the anterior surface of each foreleg as compared to 15-20 in P. castaneus (Bour, 1983).
Males have longer tails and slightly concave plastra; the plastra of females are flat.
Distribution
Pelusios seychellensis is known only from three specimens collected in 1895 on the Seychelles Islands. In 1994, a specimen was photographed and referred to by Gerlach and Canning (1996b) as P. seychellensis (Pelusios cf. castanoides). However, Justin Gerlach (pers. comm.) now states this individual may better be regarded as a hybrid P. seychellensis x P. castanoides. The Seychelles mud turtle probably is extinct.
Remark
This species is closely related to P. castaneus (Broadley, 1981a; Bour, 1983).
IUCN Red List Status (1996)
Baillie and Groombridge (1996) consider this species Vulnerable (D2), but its listing in the Seychelles Red Data Book 1997 (Gerlach, 1997a) as Extinct? is more realistic.