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The African clawed frog (''Xenopus laevis'', also known as the xenopus, African clawed toad, African claw-toed frog or the ''platanna'') is a species of African aquatic frog of the Pipidae family. Its name is derived from the three short claws on each hind foot, which it uses to tear apart its food. The word ''Xenopus'' means "strange foot" and ''laevis'' means "smooth". African clawed frogs can grow up to a length of . They have a flattened head and body, but no tongue or external ears. The species is found throughout much of Sub-Saharan Africa (Nigeria and Sudan to South Africa),〔Weldon; du Preez; Hyatt; Muller; and Speare (2004). ''(Origin of the Amphibian Chytrid Fungus. )'' Emerging Infectious Disease 10(12).〕 and in isolated, introduced populations in North America, South America, and Europe.〔 All species of the Pipidae family are tongueless, toothless and completely aquatic. They use their hands to shove food in their mouths and down their throats and a hyobranchial pump to draw or suck things in their mouth. Pipidae have powerful legs for swimming and lunging after food. They also use the claws on their feet to tear pieces of large food. They lack true ears but have lateral lines running down the length of the body and underside, which is how they can sense movements and vibrations in the water. They use their sensitive fingers, sense of smell, and lateral line system to find food. Pipidae are scavengers and will eat almost anything living, dying, or dead and any type of organic waste. == Description == These frogs are plentiful in ponds and rivers within the south-eastern portion of Sub-Saharan Africa. They are aquatic and are often greenish-grey in color. Albino varieties are commonly sold as pets. “Wild type" African Clawed Frogs are also frequently sold as pets, and often incorrectly labeled as a Congo Frog or African Dwarf Frog because of similar colorings. They are easily distinguished from African Dwarf Frogs because African Clawed Frogs have webbing only on their hind feet while African Dwarf Frogs have webbing on all four feet. They reproduce by laying eggs (see frog reproduction). Also, the clawed frogs are the only amphibians to have actual claws used to climb and shred foods like fish or tadpoles. They lay their eggs from winter till spring. During wet rainy seasons they will travel to other ponds or puddles of water to search for food. The average life-span of these frogs ranges from 5–15 years with some individuals recorded to have lived for 20–25 years. They shed their skin every season, and eat their own shed skin. Although lacking a vocal sac, the males make a mating call of alternating long and short trills, by contracting the intrinsic laryngeal muscles. Females also answer vocally, signaling either acceptance (a rapping sound) or rejection (slow ticking) of the male. This frog has smooth slippery skin which is multicolored on its back with blotches of olive gray or brown. The underside is creamy white with a yellow tinge. Male and female frogs can be easily distinguished through the following differences. Male frogs are usually about 20% smaller than females, with slim bodies and legs. Males make mating calls to attract females, sounding very much like a cricket calling underwater. Females are larger than the males, appearing far more plump with hip-like bulges above their rear legs (where their eggs are internally located). While they do not sing or call out like males do, they do answer back (an extremely rare phenomenon in the animal world). Both males and females have a cloaca, which is a chamber through which digestive and urinary wastes pass and through which the reproductive systems also empty. The cloaca empties by way of the vent which in reptiles and amphibians is a single opening for all three systems.〔Reference: National Audubon Society. Field Guide To Reptiles & Amphibians, pp: 701 & 704; Alfred A. Knopf, 24th Printing 2008.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「African clawed frog」の詳細全文を読む スポンサード リンク
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