SOFTSHELL TURTLE

any of the soft-shelled, aquatic turtles of the family Trionychidae. Softshell turtles are found in North America, Africa, and Asia in rivers or other bodies of fresh water with soft, muddy bottoms. They are distinctive in appearance, having flat, leathery, rounded shells that are commonly described as pancakelike. In addition, these turtles have webbed feet, long necks, and elongated, proboscis-like snouts bearing the nostrils at the tip. Female softshells are substantially larger than the males. Softshell turtles are swift-moving, carnivorous reptiles. They often lie buried in mud or sand and occasionally emerge to bask in the sun. Specialized tissues in the pharynx of these turtles enable them to extract oxygen for respiration from the water. Softshell turtles are valued as food. They are aggressive when captured and are capable of delivering rapid, vicious bites. There are six genera and over 20 species of softshell turtles. Most of the species are of the genus Trionyx (or Amyda), which is represented in North America, Asia, and Africa. The North American forms are the spiny softshell (T. ferox), of which there are a number of races, and the smooth softshell (T. mutica). Both species are found mainly in the United States. Maximum length of the grayish or brown shell is about 35 cm (14 inches) in the smooth softshell and 45 cm in the spiny softshell. The Old World softshell turtles include two large forms, the African T. triunguis and the Malayan Pelochelys bibroni, both of which may attain shell lengths of 60 cm or more. Lissemys, from India and Myanmar (Burma), and some related African genera are usually placed in a separate subfamily Lissemyinae.