Maik Schilde Fig. 2. Portrait of a female Batrachemys raniceps. basking, the only exception being highly gravid females. Representatives of the genus Phrynops sensu stricto lay spherical eggs, whereas the eggs of the species of Batrachemys are rather elongate in shape. The eggs of Mesoclemmys gibba are even more elongate than those of Batrachemys if the ratio between length and diameter is calculated. Bour & Zaher (2005) then reunited Batrachemys, Mesoclemmys, Bufocephala and Ranacephala to form one genus under the name of Mesoclemmys, which has nomenclatural priority. I tend to follow this concept only to a certain extent and continue regarding at least the genus Batrachemys as valid because it is visibly differentiated from the other genera in its morphology and its skull morphology in particular. There are publications (Wermuth & Mertens 1977, Iverson 1992, Rogner 1995, Vetter 2005, Fritz & Havaš 2006, Bonin et al. 2007) in which the species portrayed here is variably named Mesoclemmys raniceps, Batrachemys raniceps or Phrynops raniceps. Older works furthermore contain the synonym Phrynops nasutus wermuthi (Pritchard 1979, Ernst & Barbour 1989), which is based on the definition of Phrynops wermuthi by Mertens (1969) who failed to notice its identity with “Hydraspis raniceps” at the time. The genus Batrachemys Stejneger, 1909, presently comprises the following species: Batrachemys dahli (Zangerl & Medem, 1958) Batrachemys heliostemma McCord, Joseph- Ouni & Lamar, 2001 Batrachemys nasuta (Schweigger, 1812) Batrachemys raniceps (Gray, 1855) Batrachemys tuberculata (Luederwaldt, 1926) Batrachemys zuliae (Pritchard & Trebbau, 1984) All members of the genus are marked by having particularly large and wide heads. They 56 RADIATA 17 (3), 2008
Husbandry and first-time Breeding of Batrachemys raniceps are in general rather dusky in their colours and of secretive habits, leaving the water only for the purpose of oviposition. In contrast, the species of the genus Phrynops prefer more open waters and often exhibit bright colours on their plastra. Their heads are smaller, narrower, and furnished with well-developed barbels on the lower jaws. Batrachemys raniceps is very closely related to Batrachemys nasuta and Batrachemys heliostemma. Batrachemys raniceps has a distribution range that is largely limited to the Amazon Basin. It occurs from Peru and eastern Colombia, via northeastern Ecuador, northern Bolivia and southern Venezuela, to far into Brazil and shares its range with Platemys platycephala, Batrachemys heliostemma, Mesoclemmys gibba and Chelus fimbriata (Lehr, Michels pers. comms.). Growing to a maximum carapace length of about 25-30 cm, the Amazon toad-headed turtle is a moderately large species. Its carapace is dark brown to black and relatively flat. The wide head is grey on its upper surface and shows an irregular pattern of black spots and streaks. The upper and lower jaws are yellow or white in colour. This light zone extends to the ear. Throat, neck and nape of the neck are dark grey to black in colour, as are the limbs. The feet are very wide and furnished with well-developed webbings. The plastron can be entirely black, but may sometimes show light margins. The bridges between the upper and lower halves of the shell may be black or light brown in colour. Batrachemys heliostemma resembles Batrachemys raniceps very closely, but differs by having a wide yellow stripe that runs from the nose to behind the eye. This marking is particularly distinct in juvenile specimens. The sexes are distinguishable only by their different tail lengths, with those of the males being slightly longer than the tails of the females. Very little is known about the natural habitats of these turtles. Like Batrachemys nasuta, it Fig. 3. Ventral view of a male. RADIATA 17 (3), 2008 57
