Variable mud turtle
Another species in the subniger group is Pelusios rhodesianus, which has an elongated, black, oval carapace (to 25.5 cm) that is broader posteriorly than anteriorly and weakly keeled at best. Its carapace is flattened across the vertebrals, and if a medial keel persists it usually is represented only by a slight knob on the 4th vertebral. Vertebrals are usually broader than long, although the 3rd may be longer than broad. Neural 1 touches the nuchal and neural 8 often touches the suprapygal; neurals 7 and 8 may be reduced. Posterior marginals are smooth, not serrated. The plastron is large, only slightly smaller than the opening of the carapace, and bears a deep posterior notch. Its anterior lobe is short, only about 1.5 times the length of the interabdominal seam. The posterior lobe is not indented at the abdominal-femoral seam. The plastral formula for the three specimens we examined was: abd > fem > hum > intergul > an > pect > gul. The intergular scute is about 1.5 times as long as broad. No axillary scutes occur on the broad bridge. Bridge and undersides of the marginals are black; the plastron is usually totally black, but Broadley (1981a) reported that a few Zimbabwean individuals have irregular yellow patches or uniformly yellow plastra. The head is small with a slightly projecting snout, a bicuspid upper jaw, and two chin barbels. A long seam is present between the frontal and temporal scales, and a supralabial scale is usually absent or small with postocular and masseteric contact above. Broadley (1981a) reported that northern P. rhodesianus have brown heads with yellow vermiculations while heads of southern individuals are brown dorsally but yellow laterally. Skin of the neck and limbs is yellow, and the outer surfaces of the limbs are grayish brown.
Males have longer, thicker tails and slightly concave plastra.
Pelusios rhodesianus occurs in central and southeastern Africa from eastern Congo (former Zaire) and Uganda south to Angola, northern Botswana, Zimbabwe, and central Mozambique, with relict populations in Kwazulu-Natal (Broadley, 1981a).
This species occurs in rivers, swamps, and marshes. In Zimbabwe it seems to prefer quiet weedchoked backwaters behind dams (Broadley, 1981a).
Broadley (1981a) reported that after the first rain of the season fell on 12 September 1958 at Lochinvar on the Kafue Flats many females were found walking about the grassland presumably to oviposit. He also reported that females contained eggs in September and October. Shelled oviducal eggs and those laid in captivity in April and May totaled 11 to 14, measured 33-37 x 20-23 mm, and had pliable, thin shells.
IUCN Red List Status (1996)