Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Ornate Horned Frogs

Ceratophrys ornata

©1993 Melissa Kaplan

Natural History
The ornate horned frog (Ceratophrys ornata) is one of several species of horned frogs native to the tropical and montane rain forests; a few species of Ceratophrys can be found in more arid regions. Native to Northern Argentina, Uruguay and the Rio Grande do Sul region of Brazil, these carnivorous amphibians become very large. Their current popular name of "Pac-man Frog" eloquently describes their appearance when they lunge at prey: they appear to be all mouth. These frogs have exceptionally fast growth rates: within two weeks of hatching they have metamorphosed into their adult frog form. They then continue their rapid growth rate: often sold when they are about the size of a silver dollar, cornets will reach 6 inches within five months. Their upper eyelid is pulled up into a little point over the eye, thus giving rise to its name.

Ornates have round, plump body shapes with little demarcation between their wide head and body. Their mouths are as wide as their heads and are equipped with strong gripping jaws and a wide, pink fleshy tongue. Although it may be difficult to believe, their warty green, white and yellow skin, touched with red and black, effectively camouflage the ornate as it lies half buried in the leaf litter on the forest floor, waiting for prey to walk by. As soon as something comes into reach - another frog, lizard, snake, rodent, bird or large insects - the ornate moves its body slightly forward by pushing with its thin, short legs, grabbing and killing its prey. It takes only a gulp or two to swallow the prey whole.

Ornates are usually diurnal frogs; some may be crepuscular. Like all frogs, they sleep with their eyes open. Frogs are not animals that can be handled. Their skin is very sensitive, acting as a supplemental breathing organ. The oils found naturally on human hands can in fact be harmful to frog skin. Ornates are not particularly discriminating about what they attempt to eat - your fingers look much like naked baby rodents and birds, too tempting to resist. At least one book on amphibians states that ornates are "vicious and aggressive;" in fact, they are always interested in food, and will go for whatever comes within an inch or two of their faces. A natural human reaction upon being grabbed by an animal is to pull quickly away. When an ornate happens to be attached to your thumb, it is too easy to send it flying across the room. As frogs aren't meant to fly, this is not usually good for the frog. If you do get nabbed, stop your jerking reaction. The ornate have no teeth to speak of, and will spit out unappetizing food items; it will generally let go in a second or so.

Choosing a Frog
Look for an alert frog with clear skin. Skin that looks clouded may be a sign of a sick animal; it may also be a sign of natural skin shedding (frogs periodically shed and eat their skin). Look at the environment in which it is being kept. Many pet stores keep their ornates in an completely aquatic tank - just water and gravel. If this is the case, the water must be clean - no debris or feces floating around. When approached, or when a hand is passed in front of or over the top of the tank, a healthy frog reaction is the rapid movement of the sac under the bottom jaw; you may also hear a mild vocalization (kind of like a cow mooing, but shorter in duration). An apathetic frog is probably a sick frog.

Enclosure
Unless you have several spare tanks around, start off with the size tank you will need when your ornate is full grown - about a 10 gallon tank. It doesn't have to have a cover as ornates are not jumping frogs - they will not be able to escape. However, you do have to keep them warm, and heat will escape more easily from an uncovered tank.

Keeping more than one ornate in a tank is risky, especially if they are of different sizes: the bigger one may well eat the smaller. They do need to be together to breed, however, and can be bred during periods higher temperatures and a simulated "wet season."

Avoid stress; if you have to move your frog (transfer to a bigger tank, remove from water bowl to clean), be gentle and quick: frogs stress easily and need time to recover.

Set up a vivarium - an aquatic/terrestrial tank. In the wild, ornates spend their time on the forest floor, but the rain forest floor is very damp and the air very humid. In our temperate zone, it is more difficult to keep the humidity up, so your frog will spend much of its time in a shallow bowl of water - a glazed saucer that fits under a flower pot makes a nice pool. If you are starting out with a small frog and a large saucer, securely fit a pile of smooth stones together to make a ramp for the frog to get into the saucer from the dry part of the tank. Put aquarium gravel in the saucer to raise the bottom level, making it easier for the frog to get out. As the frog grows, you can do away with the gravel and stones (or keep them to decorate the tank).

Substrate
The rest of the tank should be set up for easy cleaning; your frog will come out of its pool for a day or so when it needs to defecate. The tank can be lined with paper towels or Astroturf, and furnished with clumps of sphagnum moss and artificial or live plants. The moss and plants can be sprayed daily with water which will help humidify the tank. You will have to refill the water in the saucer every day, more often in warmer weather. Artificial plants can be washed, and the moss replaced as necessary.

Hiding Places
In the wild, ornates bury themselves in the leaf litter; in captivity, we have to provide them with something they can hide under. You will also find that they will manage to half bury themselves under the clumps of moss and sprigs of artificial plants when they are out of the water. Place live or artificial plants so that they overhang the water saucer; this will increase the frog's sense of security and reduce stress.

Heat and Lighting
Ornates are tropical animals, and need a warm environment. Place a heating pad under the tank, and leave it on 24 hours a day. During the daytime, use an ultraviolet-B producing fluorescent over the tank. During the colder months, you will need to supplement the heat by using a red incandescent bulb during the night and, if necessary, during very cold days. The tank air temperature should be kept around 81 F. Buy an aquarium thermometer and stick it to the outside of the outside of the tank about 1" above the bottom of the tank. The saucer of water should be placed in the warmest part of the tank, as this is where your frog will spend most of its time.

Feeding Your Ornate Horned Frog
Start small ornates on crickets, putting 4-6 in the tank each day. When feeding out crickets, you must provide something for the crickets to eat if they themselves do not get eaten right away - crickets are known to snack on their predators if no other food is around. Put some oat bran mixed with reptile vitamin powder (such as Reptical) in a small jar lid; place this inside the frog tank. Some crickets are able to get under the substrate and hide there; take an occasional look, and clean out the dead crickets and cricket parts. As your frog grows, you can begin feeding mouse pinks, then mouse fuzzies, moving on up to small, then medium-sized, adult mice or rat pinkies. Buy your rodent prey at a pet store - do not feed out wild-caught rodents. Use a forceps or tongs to hold the rodent. When they move, ornates are very fast, and you may find your finger included as part of its lunch!

Keeping and Feeding Crickets
Crickets should be nutrient loaded before they are fed out to any insect-eating amphibian and reptile. Food such as poultry mash, iguana vegetable and fruit salad, tropical fish flakes, dog chow or flaked high protein baby cereal are suitable base foods. Mix your choice of food with reptile vitamin powder and offer this mixture in a large jar lid. A piece of pulpy fruit or vegetable (apple, potato, pear, squash) should also be offered to provide water. As the fruit rots, it will draw a crowd of fruit flies; these will pretty much stay where the fruit is, although some will venture out. An alternative to fruit is to cut a piece of new sponge to fit inside a small animal feeding bowl or custard-size cup. Soak the sponge with water and place it inside the tank with the crickets; they will crawl up on the sponge and extract the water from it. Always keep something in the water bowl. Crickets will drown themselves in a bowl of water if there is no sponge or rocks on which they can climb on to hop out of the bowl. If you use a sponge, remember to keep it soaked with water.

Estivation
Periodically during the year, your frog may go into a period of partial hibernation. During this period they will neither eat nor drink. They will not stay in their water bowl but instead bury themselves as much as possible beneath the foliage and substrate. Instead of shedding their skin, they retain it. It will harden up, giving your frog the appearance of being encased in plastic. Between this protective skin layer and the frog will be a thin layer of moisture; your frog will actually be taking in oxygen through his skin rather than breathing through its plugged nostrils. Do not disturb your frog when it is in this state. Estivation is done when the temperature becomes too hot or too cold for the animal's comfort. With ornates, it also happens for reasons we don't know about! Just keep the frog covered with his plant materials, keep fresh water in its bowl, and, as long as it is not losing any body mass, be patient. Eventually, when the ornate feels it is time, it will begin softening and shedding it protective covering, hop into its water, and be ready for a meal.

Medical Note...
Amphibians should be handled as little as possible as the secretions from our skin are harmful to them.

While many human and veterinary drugs and topical solutions are safe for use with reptiles and amphibians, amphibians do present a problem due to their extremely sensitive, permeable skin. Be sure to rinse out tanks and furnishings completely before replacing the amphibians. Do not use disinfectants or cleaners that may be toxic or are known to be toxic to other animals. Betadine (povidone-iodine) and hydrogen peroxide, which are frequently used on reptiles, are toxic to amphibians and must not be used on them. Instead, when the need for a topical antiseptic arises, use Bactine®, a liquid antiseptic for people.

Additional Reading

The General Care and Maintenance of Horned Frogs, Philippe de Vosjoli (1990). Lakeside CA: Advanced Vivarium Systems.

Keeping and Breeding Amphibians, by Chris Mattison (1992). NY: Sterling Publishing Inc.

Please note...
I am by no means an expert on amphibians. Compared to many people out there, I'm barely knowledgeable about their biology, natural history and captive care. So, please do your amphibs a favor and post your questions to the Amphibian forum at Kingsnake.com, or the many amphibian email lists available on the net.