(Bombinatoridae)
Class: Amphibia
Order: Anura
Family: Bombinatoridae
Thumbnail description
Often warty, aquatic toads with flattened bodies that may have a brightly colored venter
Size
1.6–3.9 in (40–100 mm)
Number of genera, species
2 genera; 10 species
Habitat
Usually found in marshes, ponds, stony mountain streams, shallow pools, or rock crevices
Conservation status
Vulnerable: 1 species; Lower Risk/Conservation Dependent: 1 species
Distribution
Much of Europe and eastern Asia
Evolution and systematics
The evolutionary relationships of the Bombinatoridae are debatable. Many authors believe that Bombina and Barbourula should be placed together with Alytes and Discoglossus in the family Discoglossidae. Others suggest that only Alytes and Bombina should be placed together and should be given the name Bombinatoridae (without consideration of Barbourula). At present, the most accepted hypothesis of relationships (and the one followed here) suggests that Bombina and Barbourula are each other's closest relative and should be grouped in the Bombinatoridae, whereas Discoglossus and Alytes are a separate, more distantly related group, the Discoglossidae.
Fossils of Bombina are known from the Pliocene to the Pleistocene. No subfamilies are recognized.
Physical characteristics
These medium-sized frogs have warty, almost "spiny" skin on the back. The color of the dorsum varies from brown-gray to greenish gray or bright green with dark spots. The belly, which is smooth, may be red, orange, or yellow with dark spots. There is no external eardrum (tympanic membrane), and the eyes have triangular pupils. Males have nuptial pads, enlarged bumps that help aquatic frogs hold on to females during breeding, on their first and second fingers.
Distribution
Bombinatorids occur in Europe east to Ukraine, western Russia, Turkey, eastern Russia and also in China, Korea, Vietnam, Borneo, and the Philippines.
Habitat
Frogs in the genus Bombina are aquatic and generally prefer slow-moving and open waters, such as swamps, ponds, and marshes. Barbourula typically are found in water in more mountainous regions, where they prefer streams and shallow pools, particularly those with stones and rocks. They often hide below rocks or in rocky crevices close to the edge of the water.
Behavior
Fire-bellied toads of the genus Bombina are diurnal and quite active in open areas during the day. These frogs have poisonous skin secretions that help protect them from predators. As is the case with many poisonous amphibians, their bright colors and distinct patterns help remind predators that they are toxic. If attacked or threatened by a would-be predator, fire-bellied toads will perform an arching "back bend" called the unken reflex; this maneuver exposes their brightly colored underbellies. Barbourulas, however, have more camouflaged color patterns and do not engage in the anti-predator behavior patterns of the fire-bellied toads. They are highly secretive and spend most of their time hiding under rocks in streams. For this reason, little more is known about their behavior.
Feeding ecology and diet
Depending on the species, the diet may consist of different proportions of aquatic or terrestrial invertebrates, including worms, snails, beetles, and bugs. Tadpoles eat plants, fungus, and small invertebrates.
Reproductive biology
Fire-bellied toads from Europe breed from late spring to midsummer; males often call throughout the day and night. Most breeding occurs in the evening, and males grasp females around the waist. Females lay up to 200 eggs on immersed vegetation or directly on the bottom of the pond. Eggs hatch in about seven days, and tadpoles metamorphose within 45 days of hatching. Although little is known about the biology of barbourulas, it seems that females lay about 80 large eggs and place them under stones in streams.
Conservation status
The IUCN lists Barbourula busuangensis as Vulnerable, and Bombina bombina as Lower Risk/Conservation Dependent. Several species have disappeared from parts of their range, and one species is known only from a single locality. Others are critically threatened because of destruction of their habitats. A few species, however, seem to have been able to tolerate human modification of the environment and may even have increased in numbers in certain areas because of human influences.
Significance to humans
Fire-bellied toads are common laboratory animals, particularly for studies of embryology and physiology. They are also common in the pet trade, owing to their bright colors, interesting anti-predator behavior, and ease of care.
Species accounts
Fire-bellied toadOriental fire-bellied toad
Yellow-bellied toad
Philippine barbourula
Resources
Books:Duellman, William E., and Linda Trueb. Biology of Amphibians. Baltimore: Johns Hopkins University Press, 1994.
Garcia Paris, Mario. Los Anfibios de España. Madrid: Ministerio de Agricultura, Pesca y Alimentación, 1985.
Gasc, Jean-Pierre, A. Cabela, J. Crnobrnja-Isailovic, et al., eds. Atlas of Amphibians and Reptiles in Europe. Paris: Societas Europaea Herpetologica and Muséum National d'Histoire Naturelle, 1997.
Herrmann, Hans-Joachim. Terrarien Atlas. Vol. 1, Kulturgeschichte, Biologie, und Terrarienhaltung von Amphibien, Schleichenlurche, Schwanzlurche, Froschlurche. Melle, Germany: Mergus Verlag, 2001.
Zug, George R., Laurie J. Vitt, and Janalee P. Caldwell. Herpetology: An Introductory Biology of Amphibians and Reptiles. 2nd edition. San Diego: Academic Press, 2001.
Other:Canatella, David. "Bombinatoridae." Tree of Life. (15 June 2002)
Frost, Darrel R. Amphibian Species of the World: An Online Reference. V2.20. 1 Sept. 2000. (15 June 2002)
[Article by: Anne M. Maglia, PhD]
