toad

toad, name applied to certain members of the amphibian order Anura, which also includes the frog. Although there is no clear-cut distinction between toads and frogs, the name toad commonly refers to those species that have relatively short legs, stout bodies, and thick skins, and are less aquatic as adults than the long-legged, slender-bodied frogs.

Sometimes the term toad is restricted to the so-called true toads, members of the family Bufonidae. These are characterized by warty skins and prominent parotid glands behind the eyes and as a group are the most terrestrial of the order. In most the feet are only slightly webbed. They range in length from about 1 to 7 in. (2.5-18 cm). Most species belong to the genus Bufo; members of these species spend much of the time on land, generally near water. They generally live in cool, moist places and absorb moisture through the skin. The white fluid that they exude through the skin, as well as from the parotid glands, is very poisonous and causes intense burning if it comes in contact with the eyes or mouth; however, contrary to an old belief, it does not cause warts. Toads, like frogs, move on land by jumping and feed on insects and grubs. Also like frogs, they usually lay their eggs in water in strands of jelly. Fertilization is external. The egg hatches into a tadpole, a gilled, aquatic, larval toad that undergoes metamorphosis into the adult.

There are about a dozen Bufo species in the United States, among them the common American toad (Bufo americanus), Fowlers toad (B. fowleri), of the E United States, and the red-spotted toad (B. punctatus), of the Southwest. The cane, marine, or giant toad (B. marinus), a large toad native to Central and N South America, was widely introduced in warm regions (Caribbean, Pacific, Australia, and Florida) to control agricultural pests but is now regarded as an invasive species; they compete with and prey on native species, and their toxic secretions can kill predators.

The spadefoot toads, burrowing toads of the family Pelobatidae, are represented in the United States by several species of the genus Scaphiopus. Toads are classified in the phylum Chordata, subphylum Vertebrata, class Amphibia, order Anura.

or tree toad

Any of some 550 species (family Hylidae) of mostly arboreal frogs, found worldwide but primarily in the New World. Most species are small, slender, and long-legged and have suckerlike adhesive disks on the finger and toe tips. Some do not climb well and live in water, on land, or in a burrow. Most species lay eggs in water. Young marsupial frogs (genus Gastrotheca), of South America, develop in a brood pouch on the female's back.

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Any member of 26 genera (order Anura) of mainly terrestrial, nocturnal, tailless amphibians. Toads have a squat body, short legs, external fertilization, and teeth in the upper jaw. They eat insects or small animals. The more than 300 species of true toads (Bufo) are found almost worldwide. They are 1–10 in. (2–25 cm) long and have thick, dry, often warty skin. Poison secreted by glands on the back and warts irritates the eyes and mucous membranes of predators. Some species' poison can paralyze or kill animals as large as dogs, but toads do not cause warts. Toads reproduce by laying in water two long jelly tubes containing 600–30,000 eggs. The genus Nectophrynoides contains the only anurans that bear live young. Seealso frog, horned toad.

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or horned lizard

Any of about 14 species of lizards of the genus Phrynosoma, family Iguanidae. They usually have daggerlike head spines (horns) and a flattened oval body with pointed fringe scales along the sides. Species range from about 3 to 5 in. (8 to 13 cm) long. They are found from British Columbia, Can., south to Guatemala and from the U.S. states of Arkansas and Kansas westward, usually in desert or semidesert sandy country. They eat mainly ants. They hide by changing their colour pattern and wriggling sideways into the sand until all but the head is covered. They may defend themselves by inflating the body quickly and (rarely) spurting blood from the eyes.

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A toad can refer to a number of species of amphibians in the order Anura. A distinction is often made between frogs and toads by their appearance, prompted by the convergent adaptation among so-called "toads" to dry habitats. Many "toads" often have leathery skin for better water retention, and a brown coloration for camouflage. They also tend to burrow. However, these adaptations are not reliable indicators of its ancestry. Because taxonomy reflects only evolutionary relationships, any distinction between frogs and toads is irrelevant to their classification.

For instance, many members of the frog families Bombinatoridae, Discoglossidae, Pelobatidae, Rhinophrynidae, Scaphiopodidae, and some species from the Microhylidae family are commonly called "toads". However, the only family exclusively given the common name "toad" is Bufonidae, or the "true toads". Some "true frogs" of the genus Rana have also adapted to burrowing habits, while a bufonid species in the genus Atelopus are conversely known by the common name "harlequin frogs".

Toads in mythology

The Moche people of ancient Peru worshipped animals and often depicted toads in their art. To Vietnamese people, toad is the uncle of the Sky. According to a Vietnamese ancient story, whenever toads grind their teeth, it is going to rain.

It is commonly believed that physical contact with a toad can cause warts on humans. Warts are, in actuality, caused by an internal viral infection; thus, a toad could not possibly cause a wart. The paratoidal glands, which toads use to secrete poison for protection, are often mistaken for warts. This misconception could very conceivably have brought about such a superstition.

See also

• List of frogs and toads by state (U.S.)
• True toad (Bufonidae)
• True frog (Ranidae)

Notes

Further reading

• Beltz, Ellin (2005). Frogs: Inside their Remarkable World. Firefly Books. ISBN 1552978699.