Common Names: Horned Frogs, Pacman Frogs
Size: Large females can reach 4-5 inches (10-13 cm) while males are smaller. The ornate horned frog (Ceratophrys ornata) is slightly larger than the Chacoan horned frog (C. cranwelli), and males of the latter species may only grow to around 3 inches (8 cm).
Appearance: Horned frogs are named so because some species, such as the Amazonian horned frog (C. cornuta), have large fleshy points above their eyes that resemble horns. The two most commonly available horned frogs – the Chacoan horned frog (C. cranwelli) and the ornate horned frog (C. ornata) – differ in appearance. Ornate horned frogs are usually marked in a mixture of bright green, brownish red, and yellow blotches and spots. Chacoan horned frogs are less colorful, typically patterned in shades of brown.
Horned frogs are also available in a number of selectively bred color morphs, especially the Chacoan horned frog which is offered for sale in brown, green, and even blue, as well as various albino forms which are yellow to orange in coloration. Hybrids between the Chacoan horned frog and the Amazonian horned frog are also available and are commonly sold as fantasy horned frogs.
Distribution, Habitat and Behavior: Native to grasslands of South America, including the dry Chaco region among Argentina, Bolivia, Paraguay and Brazil. Here they are fossorial amphibians, spending a good portion of the year inactive and underground waiting for rain. When the first storms arrive they emerge from hiding to feed and breed en masse, later returning back to a relatively inactive existence in the dirt once the weather changes again and the water dries up.
Availability: Horned frogs are some of the most commonly available pet amphibians. They are commercially bred in large numbers, usually using injectible hormones to help promote a breeding response. Brown, albino, and green Chacoan horned frogs are most common in pet stores. Other color morphs and sometimes other Ceratophrys species can be found for sale from breeders and dealers.
Housing: Horned frogs are relatively big amphibians, but they are not particularly active and spend most of their time sitting in one spot waiting for food. For a small adult horned frog, a standard 10 gallon aquarium that measures 20 inches long by 10 inches wide by 12 inches high (50 cm by 25 cm by 30 cm) is a suitable size enclosure. Juvenile horned frogs do not need as much space, and a 5 gallon aquarium that measures 16 inches long by 8 inches high by 10 inches wide (38 cm by 20 cm by 25 cm) is big enough. A screen cover is recommended to prevent things from falling in the cage, and the occasionally active horned frog from attempting to escape.
Provide a substrate that is easy for horned frogs to burrow in. Coconut husk fiber or other safe soil-like substrate is a good option. Avoid using soils that contain vermiculite, perlite, or fertilizers. The mositure content of the substrate is important, and it should never become waterlogged or completely dry. Moist paper towels or foam rubber can be used instead of soil, but must be replaced or washed frequently. Cypress mulch, sphagnum moss, and leaf litter are other suitable substrate options, although it’s recommended that frogs kept on these substrates be fed from tweezers or tongs to prevent them from swallowing a piece of bark or moss that could cause health problems. Some keepers also have success keeping horned frogs on a substrate of large river rocks. Do not use pea gravel, sand, or fir bark.
Furnish the enclosure with artificial plants, pieces of curved cork bark, and driftwood if desired. Hide spots aren’t needed if there is a deep substrate in which the frog can burrow. Naturalistic terrariums with live plants are not usually suitable for burrowing amphibians like horned frogs.
Water: A large but shallow water bowl should be available at all times. Many horned frogs end up using this as a toilet as well as a place to hydrate, so the water should be replaced regularly. Horned frogs are not especially good at swimming so the water dish should be no deeper than the frog itself. If tap water is used, it should be treated with tap water conditioner to remove chlorine, chloramines, and heavy metals.
Temperature and Humidity: Horned frogs are tolerant of a range of temperatures, but should be kept between 75°F (24°C) and 84°F (29°C) most of the time. At night the temperature can be reduced. In the wild, they experience contrasting wet and dry seasons and because of this they are not particularly sensitive to humidity levels. Some keepers choose to put adult horned frogs through a period of aestivation where temperatures and humidity are reduced and feeding is stopped altogether. During this period, horned frogs are dormant and rely on stored fat deposits and a slowed metabolism in order to survive. A low wattage infra-red light bulb can be used to heat the cage if needed. Alternatively, heat pads can be attached to the side of their cage.
Diet: The most enjoyable part keeping horned frogs is their tremendous appetite. They are ambush predators and remain motionless until potential food comes nearby, at which time they lunge from their small hole in the ground and eat or attempt to eat whatever it is that’s in front of them. Note that they are also cannibalistic and so only one frog should be housed per enclosure.
Juvenile frogs can be fed crickets, earth worms, silk worms, and occasional wax worms. A feeding schedule of two to six food items several times per week or even daily works well for growing juveniles. Adult horned frogs have large mouths and can be fed a diet of bigger food items such as night crawlers, roaches, superworms, and silkworms. They can be fed as infrequently as once every week or every other week in large quantities, and during aestivation can go without food for over four months. Vertebrates, such as pre-killed rodents and feeder fish, can be fed occasionally to both juveniles and adults but should not make up a large portion of the diet. Feeder goldfish should be avoided because they are high in fat, and it’s best if mice are fed no more than once a month. Adult frogs should have their food coated in high quality reptile vitamin and mineral supplements once every two to four feedings. Juvenile’s should have their food supplemented more frequently, as often as every feeding