The Brazilian snake-necked turtle (Hydromedusa maximiliani), locally known as cágado da serra, and also commonly known as Maximilian's snake-necked turtle, is a species of turtle in the family Chelidae. The species is endemic to southeastern Brazil.[1] It is one of the smallest Brazilian freshwater turtles reaching a maximum straight carapace length of 20cm (10inches). The species prefers streams with sandy and rocky bottoms and clear water in forests above 600m (2,000feet) elevation.[1]
The specific name, maximiliani, is in honor of German naturalist Prince Maximilian of Wied-Neuwied.[2]
First described as Emys maximiliani by Mikan (1825), it was subsequently moved to the genus Hydromedusa by Wagler (1830).[3] Several other species described later have since been synonymized with this species.[1] There are no recognised subspecies.[1]
The Brazilian snake-necked turtle is a small species reaching a straight carapace length of between 10- with a weight of 120-.[1] The carapace of the adult is oval in shape varying in color from dark gray, through to dark or light brown.[1] The plastron is a yellow or cream color. The species has a moderate-sized head with a small snout and yellowish jaws, with no barbels on the chin. The iris is black.[1] The dorsal surface of the head, neck and limbs are olive green to gray in color with a lighter cream-colored ventral surface.[1]
The Brazilian snake-necked turtle is endemic to southeastern Brazil, in the states of Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro and São Paulo.[1] The distribution is associated with the mountainous Atlantic rainforest. As a generalization it is found in mountain streams above 600m (2,000feet).[4]
The species is found in shallow streams from 15to(-) in depth, with clear, cold water and sandy or rocky substrates.[5] Because of the dense canopy and closed understory of the forests the streams receive little sunlight making basking only possible in gaps along the stream.[6]
Some populations of this species, H. maximiliani, occur within protected areas and are hence afforded some protection from deforestation and pollution which are considered major threats.[1] In regions outside these protected areas the species may be becoming fragmented and may therefore become increasingly vulnerable in the future.[1]
"Hydromedusa maximiliani".IUCN Red List of Threatened Species.1996