Important Facts about Xenopus
Xenopus have been studied since the 18th century and have a long history in laboratory research and classroom teaching. This species is a major non-mammalian laboratory animal model used to study vertebrate embryology, cellular biology, physiology, toxicology and biochemistry. Xenopus areespecially suitable for the laboratory because they are hardy, long-lived, and because under laboratory conditions, they can lay eggs year around. Thus, the eggs from laboratory Xenopus provide scientists with a continuous source of material for research. Here are some more important facts about the biology of Xenopus:
- Xenopus belong to the order Anuran (Anuran means tailless) and to the family of tongueless frogs known as Pipidae.
- Xenopus laevis (also known as the South African Clawed frog, or the Common Plantanna) and the smaller, but closely related Xenopus tropicalis (also known as the Western Clawed frog) are most commonly used in research.
- "Xenopus" is Latin for "peculiar or strange foot," referring to this species’ large webbed five-toed, three-clawed rear foot. "Laevis" means "smooth," referring to the species smooth skin.
- Xenopus are native to South Africa, in a geographic range extending from the southern Cape, to the north eastern Sudan, and to the west in Nigeria. Extensive populations are also found in Kenya, Cameroon, and the Democratic Republic Congo.
- Xenopus are an invasive species and are considered a threat to native wildlife in the USA, Britain, Portugal, Chile, and Germany.
- Xenopus are lung breathers, but they are fully aquatic. They prefer still, muddy-bottomed pools of warm fresh water. However they are readily adaptable and have been found in flowing river beds and streams, in salt water, and in areas where ambient temperatures vary from freezing to desert-hot.
- Xenopus are carnivorous predators with an indiscriminate, voracious appetite. They are scavengers and will readily eat carrion, but they prefer live food: fish, birds, slugs, worms, and other aquatic invertebrates. They are cannibalistic, as are many Anuran species—larger frogs will eat froglets, tadpoles and their own eggs.
- Xenopus skin is permeable and slimy. The slimy protective slime, or mucous layer, serves as a barrier against pathogens and abrasion and has antibacterial, anti-viral and antifungal properties. Care should be taken when working with this species not to damage or remove the slime layer.
- Xenopus dorsal skin color can be pale olive green to brown, with mottled markings. Skin pigments are under hormonal control and allow Xenopus to change color to better adapt to their habitat.
- Xenopus have nerve endings along the sides of the body and around the head and eyes that form the lateral line system. The lateral line system is used to detect prey and predators via changes in water movement.
- X. laevis have been known to survive 15 or more years in the wild and 25-30 years in captivity.
- The males of this species are smaller than the females, and while neither “croak”, they do call to each other under water using a guttural, trilling sound.