Harlequin Frogs True Toads and Relatives: Bufonidae

The toads in this family are known as the "true" toads. All other frogs that are called toads are not really toads. They may have a toad's body shape or have numerous warts, but they are not true toads. One of the features true toads have that no other type of frog has is a Bidder's organ. A Bidder's organ is a female body part that is found inside a male toad. This organ does not appear to do anything in a healthy male toad. It does, however, help to tell a true toad apart from all other species of frogs that exist on Earth.

True toads have other hidden features, too. They have an odd joint between their lower backbone, or spine, and their hip bones that makes it difficult for the toads to jump well. They can walk or hop short distances, but they cannot leap several feet like some of the other species of frogs. They have only seven bones in their spines instead of the eight that most other frogs have; they have fewer bones in their front and back feet, and they have shorter toes than other frogs typically have. In addition, the pair of shoulder blades, which are usually separate in other frogs, are fused together in toads into one big shoulder blade that stretches across the whole upper back. Their lack of teeth also sets the true toads apart. None of the true toads have teeth on the upper jaw, while almost all other frogs do.

The most noticeable feature of true toads is their warty skin, especially the huge "wart" on the back of the head. The big "wart" is called a paratoid (pair-RAH-toyd) gland and makes a white, liquid poison that looks like milk. Not all true toads have paratoid glands, but the glands are usually very noticeable in the toads that do have them. The pair of paratoid glands on the American toad, for example, looks like large, flat water balloons that extend from behind the eye to the front of the back. Some species of frogs that are not true toads also have paratoid glands, so just seeing a paratoid gland is not enough to identify a frog as a true toad.

Many toads have plump bodies, short heads with rounded snouts and large mouths, eardrums that are visible on the sides of the head, short legs, and numerous warts on their backs and legs. The Houston toad is a good example. It has a fat-looking, round body that is covered with many small warts. Its head is short with a wide mouth and visible eardrums. Its front legs are thick but rather short, and its hind legs are much shorter than the legs of a leaping frog. Some of the toads in this family, however, look little like this typical toad. The harlequin frog, which is actually one of the true toads, has long and thin front legs, long hind legs, a thin body, no eardrums, and quite smooth skin.

In general, true toads are shades of brown, green, and/or gray, which allows these rather slow creatures to blend in with the background. The Chirinda toad, for instance, has a light brown back and legs and dark brown sides. When it sits still, it almost disappears against the dead leaves of its habitat. The green toad, which lives in Europe, Asia, and northern Africa, is brown with green blotches, a pattern that blends in with the ground where it lives. A few species, however, have very bright colors. The Yungas redbelly toad has a black and sometimes green back, but a bright red belly, and the male golden toad, which is now extinct, or no longer in existence, was vivid orange.

True toads also come in many different sizes. The Roraima bush toad, which lives in South America, grows to only 0.8 inches (2 centimeters) long from the tip of the snout to the end of the rump, while the marine toad can reach 9 inches (23 centimeters) in length. The Rococo or Cururu toad, can grow even larger, sometimes reaching nearly 10 inches (25.4 centimeters) long.