Oriental fire-bellied toads occupy a variety of different habitats. They live at high elevations in spruce, pine or deciduous forests, river valleys, swampy bushlands, and open meadows. Bombina orientalis lives in or around various water types, including stagnant and running water in lakes, ponds, swamps, streams, springs, even puddles and ditches. Typically, this species stays relatively close to water, but in late summer they occur up to a few hundred meters from water.
Habitat Regions: temperate ; terrestrial ; freshwater
Terrestrial Biomes: forest
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools
Wetlands: marsh ; swamp ; bog
Other Habitat Features: riparian
The main predators of Bombina orientalis are birds and larger aquatic animals. Oriental fire-bellied toads are poisonous to eat and, when threatened, they exhibit a posture known as unkenreflex. They flip on their backs and arch their spines. The brilliant warning spots on their underside warn potential predators of their toxicity and may deter predation. Their dull-colored back provides perfect camouflage to blend in with the muddy waters they inhabit.
Known Predators:
Anti-predator Adaptations: aposematic ; cryptic
Oriental fire-bellied toads are dark-colored dorsally, ranging from brownish-gray to bright green. When the dorsal surface is colored more vividly, dark spots are typically also present. The ventral surface is brightly colored, usually with dark spots over brilliant red-orange or yellow reticulated patterns (hence the name "fire-bellied"). The pupils are triangular. The skin is covered in tubercles (warts), except on the ventral surface, where tubercles are only present near the cloaca (the terminal part of the gut). Of the three species in the genus Bombina, Oriental fire-bellied toads have the most pronounced tubercles. Tubercles on the ventral side of the animal are elevated and acute, sometimes feeling like sharp needles. These toads have no tympanic membrane.
Females are generally larger than males. During the breeding season, males develop nuptial pads on their first and second fingers, have more tuberculate skin, and have thicker forearms.
Range length: 3.5 to 8 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; poisonous
Sexual Dimorphism: female larger; sexes shaped differently
Bombina orientalis can live up to a maximum of 30 years in captivity. Maximum longevity in the wild is estimated at 20 years.
Range lifespan
Status: wild: 20 (high) years.
Range lifespan
Status: captivity: 30 (high) years.
Average lifespan
Status: captivity: 2.3 years.
Bombina orientalis is found in northeast China (the provinces of Heilongjiang, Hebei, Shandong, Anhui, and Lianoning). These toads can also be found in Korea, Thailand, and southern Japan (the islands of Kiushiu and Tsushima). Bombina orientalis also occurs in the Primorye and Khabarovsk regions of Russia.
Biogeographic Regions: palearctic (Native ); oriental (Native )
Oriental fire-bellied toads, like most frogs and toads, primarily perceive prey through movement. They wait patiently for their prey to draw near and then pounce quickly to capture the prey. As larvae, Oriental fire-bellied toads consume algae, fungi, detritus, plants, and protozoans. As adults, their diet consists of terrestrial invertebrates, including worms, molluscs, and insects.
Animal Foods: insects; terrestrial non-insect arthropods; mollusks; terrestrial worms
Plant Foods: algae
Other Foods: fungus; detritus ; microbes
Primary Diet: carnivore (Insectivore , Molluscivore )
Oriental fire-bellied toads prey upon terrestrial invertebrates and are also preyed on by bird species and larger aquatic animals.
Bombina orientalis is a popular toad species in the exotic pet trade. They are hardy animals with long lifespans.
Positive Impacts: pet trade
Bombina orientalis is a poisonous species, although are popular as pets. Their skin toxin is not poisonous to human skin, but is harmful when rubbed in the eyes, mouth, or on broken skin. Hands should be washed thoroughly before and after handling. Handling oriental fire-bellied toads can result in itchy eyes and a runny nose.
Negative Impacts: injures humans (poisonous )
Oriental fire-bellied toad females lay eggs in clusters of 3 to 45. These clusters are deposited every 7 to 10 days. with a total clutch size of 38 to 257 eggs. Typically, eggs are laid on submerged plants near water's edge. Eggs hatch after a period of 3 to 10 days. In the first week following hatching, the tiny larvae absorb their yolk sacs. Oriental fire-bellied toad tadpoles have a gill slit on the ventral surface that projects outward, this gill slit is called a spiracle. After about 6 to 8 weeks, the hind legs and the lungs start to take shape. After 10 to 14 weeks, tadpoles reach about 3.5 cm in length and begin to metamorphose. After the 12th week, they start to emerge from the water and lose their tails. The transformation process into an adult toad takes approximately 5 months.
Development - Life Cycle: metamorphosis
Bombina orientalis is not currently considered a threatened species.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Vocalizations are the primary form of communication and are mostly used during the mating season. Oriental fire-bellied toads have a soft, musical call that sounds like a tapering "oop...oop...ooop." Males croak to attract females, and to warn other males of mistaken identity.
Like most frogs and toads, Oriental fire-bellied toads use vision primarily to detect prey.
Communication Channels: visual ; acoustic
Other Communication Modes: choruses
Perception Channels: visual ; tactile ; acoustic ; chemical
In cases of extreme danger, Bombina orientalis can excrete so much poison that its entire body becomes covered in a soapy foam.
Males court females by continuously calling while floating in shallow water. The mating call sounds like a bark and lasts about twelve seconds. Males sit and croak until a female approaches for mating.
In the wild, there are often more males than females at breeding sites, sometimes as many as ten males for every female. Waiting males jumps onto the back of passing toads, hoping it to be a female. Inevitably, males sometimes jump on other males. The target male lets out a loud croak to indicate a mistake has been made. When a female is encountered, the male and female enters amplexus. Females swim around with the male hanging on, fertilizing the eggs as she lays them.
Mating System: polygynandrous (promiscuous)
After fertilization, the jelly layers of the eggs absorb water and swell. The eggs remain in this "jelly" state until hatching. Breeding begins with warming weather in the spring and continues throughout the summer. Breeding occurs from May through mid-August eggs hatch after 3 to 10 days. Most hatching occurs in June and July. Females are capable of laying more than one clutch per season. They deposit from 38 to 257 eggs in portions from 3 to 45 eggs every 7 to 10 days. In captivity, the breeding season begins after a cooling winter period with simulated rain.
Breeding interval: Breeding may occur multiple times during a year.
Breeding season: Breeding occurs throughout the warm season, from May to mid-August.
Range number of offspring: 38 to 257.
Range time to hatching: 3 to 10 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
Bombina orientalis larvae hatch 3 to 10 days after egg laying. There is no direct parental care. The young are left to fend for themselves following hatching. Indirectly, females can influence development of their young by varying the environment the eggs are placed in and energy investment in the eggs. Egg size and water temperature are two such factors. In cold water, larvae that developed from larger eggs had greater fitness than those that developed from small eggs. In warmer environments, larvae that developed from small eggs had greater fitness than those that developed from large eggs.
Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)
The Oriental fire-bellied toad (Bombina orientalis) is a small semiaquatic frog species found in northeastern Asia, where they primarily dwell in slow-moving bodies of water and temperate forests. Quite common throughout much of their range, these frogs have mild toxins that can be excreted through their skin, with their vibrant underbellies serving as a warning of this. While not a true toad, their green and black skin is covered in small tubercles, giving them a toadlike appearance. Their sounds, mainly produced by males during the mating season, are very unlike those of other frogs. While their population is in decline, their numbers are still high overall, with the International Union for Conservation of Nature (IUCN) rating them as a least-concern species. They are commonly kept as pets in land and water vivaria, as a relatively easy-to-care for species. They are also frequently used in scientific research, with their behavior, vocalizations, and learning skills all moderately studied.
According to the American Museum of Natural History, the red-bellied toad, Chinese bell toad, Oriental bell toad, eastern fire-bellied toad, and Korean fire-bellied toad are all common names that have been used to describe the species at one point or another.[2]
The Oriental fire-bellied toad was first described by George Albert Boulenger as Bombinator orientalis, who placed it within the same genus as the European fire-bellied toad and the Apennine yellow-bellied toad, noting their many similarities. He considered it an "intermediate" between the latter two species, although he thought it was closer to the Apennine yellow-bellied toad overall. His research was based on 19 specimens housed in the British Museum. The three species have been moved into the genus Bombina in 1907 by Leonhard Stejneger.[3][4]
The toad was later divided into two subspecies in 1972, B. o. practicola and B. o. silvatica, with the former being more aquatic and the latter more terrestrial, although newer research has found them to display few genetic differences, despite some physical ones. These findings support their classification as a monotypic species, albeit one with multiple morphs that may have diverged rather recently.[5] A population in Beijing, despite having existed for less than a hundred years, has shown signs of evolution at a molecular level, displaying genetic uniqueness from the original population. While genetic diversity is somewhat low, it is still high enough that the Beijing toads may continue to survive.[6]
In the late Quaternary, seismic activity at the Yilan–Yitong fault zone is believed to have split the toad into two subpopulations in its native range, with the much smaller western one having low genetic diversity. In more recent times, gene flow has begun to occur between the two.[7]
Oriental fire-bellied toads can be bright, grayish, or brownish green, with black mottling on their dorsal regions. Like other Bombina species, B. orientalis has a brightly colored ventral region, which can be yellow, red, or orange-red, mottled with dark spots.[8] The finger and toe tips are usually red.[3] The skin on its upper side is covered in small tubercles, the most pronounced of the genus Bombina.[9] Although it is typically referred to as a toad, the fire-bellied toad is not a true toad.[10] They can reach a length of about 3.8–5.1 centimetres (1.5–2.0 in), weighing about 28–57 grams (0.99–2.01 oz).[11] Males and females can be told apart by the males' nuptial pads on their first and second fingers.[12]
Besides having more noticeable tubercles on their skin, B. orientalis can also be distinguished from other members of Bombina by their lack of gular sacs (like B. pachypus and unlike B. bombina) and nuptial pads (like B. bombina and unlike B. pachypus, although later research has shown that males do in fact have a few, as previously mentioned[12]). Subtler differences include their belly coloration, which is typically more red than yellow (unlike B. pachypus) and bright finger tips (unlike B. bombina).[3]
The toad can be found in Korea, northeastern Russia, (where they have become rather rare[12]) and northeastern China, and possibly southern Japan, specifically Tsushima Strait, although the latter is very likely erroneous, as a team of Japanese researchers in the later half of the 20th century was unable to locate any.[13] There is also a somewhat genetically distinct population in Beijing that was introduced from Yantai in Shandong in 1927 by Mr. Liu Cheng-chao. About 200 were released into wetland habitats, where they later bred.[6] There have been multiple reports of escaped specimens in Broward County, Florida, US, mostly in the immediate vicinity of an animal importer's facility.[14] There have been no other reports of such occurrences in the United States, and there are no well-established escaped populations.[15]
They are semiaquatic, generally dwelling in slow-moving streams or ponds. When out of the water, they can often be found in coniferous and broadleaved forests.[11] They can be found at elevations of up to 1,100 metres (3,600 ft).[1] They are very resilient to environmental disturbance, especially compared to other amphibians, and as such can be found living and even breeding in heavily polluted water.[16]
Bombina orientalis are one of the most plentiful amphibians in their native lands, particularly the central part of their range. The toads are diurnal (active during the day), and studies have found that while they can acquire some from their diet, Oriental fire-bellied toads rely partly on sunlight to obtain adequate levels of vitamin D3.[17][18]
As larvae, Oriental fire-bellied toads consume algae, fungi, detritus, plants and protozoans. As adults, their diet consists of terrestrial invertebrates, including worms, molluscs and insects.[8] Their diet in the wild contributes to their toxicity, and for that reason, wild specimens have more potent toxins.[19] Oriental fire-bellied toads are incapable of extending their tongues to catch prey, but must instead leap at their target.[8]
Breeding takes place around mid-May, when temperatures become warmer. It is at this time that the toads emerge from hibernation.[12][11] Males call to the females with a light sound that is comparable to a musical triangle. They will jump onto the backs of any other fire-bellied toad that happens to pass by, which in some cases will cause them to accidentally attempt to mate with other species of amphibians, fish, plants, or even human fingers. Females lay 40 to 110 eggs in a large cluster near the surface of the water. The tadpoles begin to develop legs in 6–8 weeks, and are fully metamorphosed by August or September.[8]
Unusually for a frog species, the Oriental fire-bellied toad does not have an eardrum or resonator, making their calls by inhaling.[8] The males' light mating calls are similar to those of B. bombina.[12] While vocalizing, males will attempt to space out their calls so as to avoid overlap between different individuals, a behavior also observed in European fire-bellied toads.[20] Females have been found to be quickly attracted to the advertisement call, but not the release call, displaying an ability to differentiate between them. Males typically ignore the advertisement calls, but will approach the source of release calls. In both cases, visual stimuli are also necessary to trigger a reaction.[21] In addition to their lighter sounds, they can also produce a croaking noise.[9]
Oriental fire-bellied toads can discourage most predators with their poisonous skin, with the bright colors of their undersides warning predators of their toxicity.[11] The toxin is secreted through the skin mostly from the hind legs, and sometimes the belly, in a milky substance when the frog is disturbed or frightened. When producing this substance, the frogs may also lie on their backs to show the color of their bellies, indicating their potential danger, holding up their limbs and arching their heads.[8][15] This does not always work, and in addition to predation by birds and mammals, grass snakes and other water dwelling snakes are known to the consume the toads without any ill effect.[12][8]
The skin of Oriental fire-bellied toads contains bombesin, a peptide first isolated from their relatives, European fire-bellied toads (and later other types of frogs, in the genera Rana and Phyllomedusa). Among other effects, bombesin hinders gastric functions in mammals, including dogs, cats, rabbits, and rodents. Later studies on B. orientalis discovered that the peptide came in three separate forms.[22][23]
Oriental fire-bellied toads are rapid learners, especially compared to other frogs. In an experiment, slightly dehydrated toads were found able solve both simple and more complex mazes using water as a reinforcement, unlike other types of frogs (members of Rana, Bufo, and Hyla simply either did not try or leapt around aimlessly). In a simple T-maze, with their target on the right side, 80% had navigated their way successfully in only three days, with 100% having finished after four days. The left side proved more challenging, with 80% finished in three days, but the rest not done until day eight.[24]
As common amphibians, B. orientalis make excellent model organisms for studying the effects of pollution and toxic chemicals on local environments. Studies involving them having demonstrated the harmful effects of carbaryl (which include bent trunks, thicker-set bodies, bent tails, and ventral blistering) and nonylphenol (which significantly decreased overall survival rates) on amphibian embryonic development.[25][26]
The oriental fire-bellied toad was listed as least concern species by the International Union for Conservation of Nature with little threat of extinction, although the population is declining, but not at a significant rate.[1] They occur in many protected areas in China and the Koreas, as well as six Russian nature reserves. The population in the Russian part of their range may be more threatened than others. Dangers include pollution, urbanization, and use in traditional Chinese medicine.[8]
Bombina orientalis are relatively easy to care for in captivity, requiring little in the way of specialized lighting or heating and readily consuming feeder insects or small feeder fish.[10] Handling can require caution, as although harmless to the skin, the mucus can cause discomfort to the mouth and eyes,[8] however captive individuals generally are less toxic.[19] The toxin does not pose a significant threat to human health.[10] In captivity, Oriental fire-bellied toads often live for around 12 years, but in some cases can live up to 30.[19]
The Oriental fire-bellied toad (Bombina orientalis) is a small semiaquatic frog species found in northeastern Asia, where they primarily dwell in slow-moving bodies of water and temperate forests. Quite common throughout much of their range, these frogs have mild toxins that can be excreted through their skin, with their vibrant underbellies serving as a warning of this. While not a true toad, their green and black skin is covered in small tubercles, giving them a toadlike appearance. Their sounds, mainly produced by males during the mating season, are very unlike those of other frogs. While their population is in decline, their numbers are still high overall, with the International Union for Conservation of Nature (IUCN) rating them as a least-concern species. They are commonly kept as pets in land and water vivaria, as a relatively easy-to-care for species. They are also frequently used in scientific research, with their behavior, vocalizations, and learning skills all moderately studied.
