iPhone App
Electronic Field Guide to the
Reptiles and Amphibians of
Southern California
Available Now at the
iTunes App Store. |
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Introduced - not native to California
It is against the law to capture, move, possess, collect, or distribute this invasive species in California.
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Adult in aquarium, San Diego County |
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Claws on hind feet |
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| Tadpoles |
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| Tadpole out of water, San Diego County |
Tadpole in aquarium, San Diego County |
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| Tadpole in aquarium, San Diego County |
Tadpole with mouth open |
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| Tadpoles in water, Orange County. © Jonathan Hakim |
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Habitat |
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| Habitat, seasonal pond, San Diego County |
Habitat, Los Angeles County |
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Habitat, San Diego County |
Habitat, San Diego County |
Habitat, Orange County |
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| Short Video |
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| A tadpole swimming underwater. |
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Description |
Size |
| Adults are 2 - 5 5/8 inches long from snout to vent (5.1 - 14.3 cm). |
| Appearance |
| A smooth-skinned frog with a flattened body and a small head with a blunt snout and small upturned eyes with no lids. Olive to brown above, with dark markings. Whitish below, sometimes spotted. No tongue. Forefeet are unwebbed. Hind feet are fully webbed with sharp black claws on the inner toes. Tadpole is translucent with tentacles at the mouth corners and a slender tail ending in a filament. |
| Voice (Listen) |
| A 2-part trill, about 1/2 second, repeated up to 100 times per minute. Males have no vocal sacs and call from underwater during the day and at night. Calls are only faintly heard in the air. |
| Behavior |
Totally aquatic, but will move over land on rainy nights and at night when their water source dries up, sometimes in mass migrations. Able to tolerate brackish habitats. Cannot tolerate loss of water or sustained travel over dry land. When pond water evaporates, frogs make and stay in shallow pits in the mud where the water temperature remains cooler than the surface temperature. In Africa, frogs burrow deep into the mud that remains when a seasonal pond dries up, where they can survive for at least 8 months without food.
When not feeding, frogs rest on the bottom or on rocks. Has been observed tolerating a wide range of conditions, including 40 percent seawater, freezing water, hot desert conditions, long periods without food, and estivating without water.
Releases slippery mucous secretions from the skin to repulse predators.
Adults live up to 16 years. |
| Diet and Eating |
| Feeds on anything it can catch; aquatic invertebrates, fish, amphibians, including its own larvae and recent metamorphs. A very formidable predator. Finds prey by scent, and uses its toothed jaws to hold the prey while shredding it with its rear claws and pushing it into the mouth with its forearms. This allows a frog to eat prey that is too large to swallow whole, and to scavenge. Tadpoles swim head down, vibrating the tail filament to stir up food, including algae, diatoms, protozoans, and bacteria. |
| Reproduction and Young |
Reproduction is aquatic. Fertilization is external. In California, breeds any time from January to November with a peak in April and May. In Africa, frogs are known to migrate to newly-filled rain pools to breed, but this has not been observed in US Populations.
Females mature quickly - about 6 months after metamorphosis. A female lays several hundred to thousands of eggs, depositing them singly or in small groups on vegetation and rocks. Females can produce multiple clutches each season. Eggs hatch in 2 to 3 days.
Tadpoles congregate in pools, often schooling and feeding in the middle of deeper water to avoid predation by fish. Transformation time in the wild is not known, but tadpoles transform in 10 - 12 weeks in captivity. |
| Range |
Originally native to South Africa. Brought to the US in the 1940's and widely used as a standard amphibian for laboratory study and human pregnancy testing in the 1940's and 1950's. ( "...imported in the 1940s and '50s for use in diagnostic pregnancy tests. [When injected with the urine of a pregnant woman, the frog releases eggs - the telltale sign.]" Alan Burdick - Out of Eden. ) A popular aquarium pet, it is now banned in several states including California. Released or escaped laboratory animals and pets were introduced into California mostly before the species was banned in California in the 1960s.
First found established in the wild in California in 1968. It has become established in California primarily in San Diego, Orange, and Los Angeles counties, but has also been found elsewhere, including San Bernardino, Santa Barbara, Riverside, Imperial, Kern, Ventura, and Yolo Counties, and recently in a small pond in San Francisco's Golden Gate Park. Xenopus has been reported from nine states including California, and established populations have also been found in Tucson Arizona, and extreme northern Baja California Del Norte. |
| Habitat |
| In California, inhabits a variety of aquatic habitats, many of which have been disturbed or made by humans, including slow streams and drains, marshes, ponds, drainage ditches, flood channels, cattle tanks, sewage plant ponds, and golf course ponds. The highest densities of this species are found in permanent well-vegetated waters with soft substrates that do not freeze. Inhabits waters in arid and semi-arid regions in its native South Africa. |
| Conservation Issues (Conservation Status) |
Established and spreading. Most suitable freshwater aquatic habitats in California are at risk of colonization, especially with continued human-aided introductions. A threat to native amphibians and fishes, including several endangered species. Importation and possession of this frog is prohibited in California. Still a popular pet frog in some states, but banned in several others. Eradication efforts by using poisons, draining ponds, and collecting and removing frogs, are not usually successful at removing all frogs or preventing frogs from nearby areas to re-colonize the water source.
It is against the law to capture, move, possess, collect, or distribute this invasive species in California. See California Department of Fish and Game Restricted Species Regulations information: http://www.dfg.ca.gov/licensing/specialpermits/
See: California Department of Fish and Game Restricted Species Regulations
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Taxonomy |
| Family |
Pipidae |
Tongueless Frogs |
| Genus |
Xenopus |
Clawed Frogs |
| Species |
laevis |
African Clawed Frog
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Original Description |
Not available
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Meaning of the Scientific Name |
Not available
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Alternate Names |
None
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Related or Similar California Frogs |
None in California.
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
AmphibiaWeb
Stebbins, Robert C., and McGinnis, Samuel M. Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.
Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.
Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.
Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Amphibians of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.
Elliott, Lang, Carl Gerhardt, and Carlos Davidson. Frogs and Toads of North America, a Comprehensive Guide to their Identification, Behavior, and Calls. Houghton Mifflin Harcourt, 2009.
Lannoo, Michael (Editor). Amphibian Declines: The Conservation Status of United States Species. University of California Press, June 2005.
Wright, Anna. Handbook of Frogs and Toads of the United States and Canada. Cornell University Press, 1949.
Davidson, Carlos. Booklet to the CD Frog and Toad Calls of the Pacific Coast - Vanishing Voices. Cornell Laboratory of Ornithology, 1995.
Alan Burdick. Out of Eden: An Odyssey of Ecological Invasion. Farrar, Straus and Giroux, 2006.
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The following status listings come from the Special Animals List which is published by the California Department of Fish and Wildlife.
It is against the law to capture, move, possess, collect, or distribute this invasive species in California.
See: California Department of Fish and Game Restricted Species Regulations
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Organization
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Status Listing
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| U.S. Endangered Species Act (ESA) |
None |
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| California Endangered Species Act (CESA) |
None |
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| California Department of Fish and Wildlife |
None |
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| Bureau of Land Management |
None |
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| USDA Forest Service |
None |
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| Natureserve Global Conservation Status Ranks |
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World Conservation Union - IUCN Red List
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