Saturday, June 20, 2009

Toad

Toads are rough skinned, generally land dwelling, tailness amphibians closely related to frogs. True toads make up the family Bufonidae. More than 200 species, classified in the genus, Bufo, are found in North and South America, Asia and Africa from sea level to more than 4,500 m (15,000 ft) in the Himalayas. Member of other genera are also found throughout the world except in Australia and Antartica, some only in tropical areas.

The name toad is also used to refer to certain frogs. These include the Mexican burrowing toad, Rhinophrynus dorsalis, family Pipidae, the Surinam toads, genus Pipa, family Pipidae; the fire belled toads, Bombina, and the midwife toad, Alytes obstetricans, family Discoglossidae; and the spadefoot toads, Scaphiopus, family Pelobatidae.

Toad generally have squat bodies and short legs. Most are moderate sized, about 5 to 8 cm (2 to 3 in) long, some, however, such as the oak toad, Bufo quercus, may be only 20 to 30 mm (0.8 to 1.2 in), others, such as Blomberg’s toad, B. Blomberi, may reach 150 mm (6 in) or more. Most are drab. A few genera of toads are brightly colored or spotted. Malaysian tree toads, pedostibes, for example are green with yellow and blue spots, and male Costa Rican toads, B. periglenes, are bright gold.

A toad’s thick, warly skin allows it to inhabit drier regions than does a frog. Toads are found in fields, gardens, woodlands, and meadows as well as moister areas. They frequently use horny projections on their hind feet to dig shallow burrows in which to hide. As cold weather approaches, they find a secluded spot and hibernate. Toads do not jump as frogs do, but make short hops or even walk. They are carnivorous, feeding mostly on insects. Toads are the prey of many animals. When provoked or injured, toads secrete a poison from their skin. In most species poison glands are scattered over the body, but they may be concentrated on the side of the neck. Toads also defend themselves by inflating their bodies, a tactic that increases their bulk and makes them harder to swallow.

Toads typically breed in water. they are very prolific most laying 20,000 eggs in a single clutch, with the giant toad producing as many as 100,000 eggs at the time. The eggs hatch into tailed aquatic larvae (tadpoles) that metamorphose into the adult from in a few weeks. Several toads depart from this mode of reproduction. Some species lay eggs on land and lack a free swimming in tadpole stage; in other fertilization is internal and birth is given to fully formed toadless. (Animals World)

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