Radiata2008(3)e

Oliver Römpp Fig. 2.

Oliver Römpp Fig. 2. Acanthochelys pallidipectoris. Northern Brazil is where the Brazilian radiolated swamp turtle, Acanthochelys radiolata (Mikan, 1820), occurs. It inhabits stagnant bodies of water such as ponds and swamps along the coast of the state of São Paulo to Rio de Janeiro. Acanthochelys radiolata can reach about 20 cm in carapace length (Ernst et al. 2008). The dorsal shell is light to dark brown in colour and marked with black blotches. The name Acanthochelys radiolata refers to these blotches forming a radiating pattern that extends from the centre of the carapace to its margins. The limbs are uniform grey to greyish black in colour. Many specimens show a pattern of fine, light grey or beige and dark grey lines on the head. This marbled pattern often remains distinct even in adult Acanthochelys radiolata. By far the largest species is the Pantanal swamp turtle, Acanthochelys macrocephala (Rhodin, Mittermaier & McMorris, 1984). It can grow to lengths of up to 23.5 cm (Ernst et al. 2008). Populations are known from the catchment of the Río Grande in central Bolivia to the Pantanal region of southern Brazil and central Paraguay (Buskirk 1988). The colouration of the carapace varies from dark yellow to light brown. Its head is unusually large and wide for a species of Acanthochelys, which becomes even more conspicuous with age. The upper side is dark grey to almost black while the lower side is cream in colour. Juveniles sport a distinct vermiculated pattern on the Fig. 3. Portrait of an Acanthochelys radiolata. 40 RADIATA 17 (3), 2008

South American Swamp Turtles of the Genus Acanthochelys dorsal side of the head that consists of shades of grey. These markings may still be present in larger specimens as well. In its overall appearance, Acanthochelys macrocephala bears some resemblance of the tuberculated toad-headed turtle, Batrachemys tuberculata. Husbandry All four species are well suited for being kept in human care and do not normally prove difficult if only some basic requirements are given the necessary attention. For the small-sized Acanthochelys pallidipectoris and Acanthochelys spixii, the water level should not be too high since both are poor swimmers. It is even recommendable to initially provide a water level so low that the turtles can reach the surface without having to swim at all. Their aquaterrarium should always provide gently rising transitions to the terrestrial part or offer objects that can be scaled easily to reach the water surface. Acanthochelys macrocephala and Acanthochelys radiolata are much more skilled when it comes to swimming. In fact, the latter mentioned species can even be termed an excellent swimmer. All species of Acanthochelys readily venture onto the land provided and often bask for extended periods of time. They may even spend the night on land (Acanthochelys spixii and Acanthochelys pallidipectoris). The regions where members of the genus Acanthochelys occur naturally are often subjected to long periods of drought during the summer months, causing the natural waters to be dry for weeks if not months or water temperatures to rise beyond tolerable levels (>35 °C). The turtles respond to these phases by going on Fig. 4. Acanthochelys spixii, hatchling. land and aestivating in the leaf litter beneath bushes or amongst roots. Animals that are kept in a greenhouse respond in a similar manner to high summer temperatures by going on land and seeking out shaded spots under the plants of the terrestrial section. The turtles will then often remain on land for days or even weeks or return to the water only during the late evening hours. All species of Acanthochelys feed readily on the food provided and are not choosy at all. They are fed with homemade turtle jelly (after the recipe suggested by Artner 1998), beef heart, shrimps, baby mice, earthworms, mussel meat, and dry feed. The turtle will often bite off pieces from cuttlefish shell that is left floating in the water and so regulate their calcium requirements on their own. Adult animals are fed two or three times every week. Hatchlings and juveniles receive food daily or every other day in the shape of mosquito larvae and finely chopped beef, fish, and shrimps. A little later, they will also take the mentioned turtle jelly. As a result of its balanced constituents, the jelly has proven to be of great value and therefore forms the primary food for my animals. RADIATA 17 (3), 2008 41