New High Score: Perfecting Pacman Frog Care
Affectionately named ‘pacman’ frogs for their rotund bodies, huge mouths and insatiable appetites, horned frogs are easily some of the best pet frogs available. Their straightforward care requirements and comedic characteristics make them popular first pets, but has this hardy reputation impacted the way we keep horned frogs?
Cranwell’s Horned Frog
There are eight separate species of horned frog, all belonging to the Ceratophrys genus and coming from different parts of South America. Several species are reasonably well-established in the hobby, but C. cranwelli, takes the top spot for its rich spectrum of colours and morphs available. C. cranwelli was previously thought to be synonymous with C. ornata, but several morphological differences allowed researchers to distinguish the two. Now, with limited genetic diversity, the Ornate or Bell’s horned frog (C. ornata) is much less frequently produced.
The main appeal of horned frogs in captivity, aside from their ‘cute’ personalities as froglets, is their ease of care. As a predominantly fossorial species, horned frogs do not require much space when compared to other amphibians. However, they will sometimes leave their burial spot at night and as a fast-growing species, must be given appropriately sized enclosure upgrades. These frogs generally reach sexual maturity at around two years old.
Unlike C. ornata, which is found in the tropical Amazon, the Cranwell’s horned frog comes from the Chaco region of South America. There is indeed some overlap between their distributions, but the Ornate horned frog inhabits the tropics of the North, whereas Cranwell’s horned frogs prefer the plains of the South. The Chaco is a dry savannah that stretches across Argentina, Bolivia, Brazil, and Paraguay. With many keepers linking South America with tropical rainforests, it is understandable that this is the most common misconception to cause husbandry errors. Keepers should simulate the natural environment of C. cranwelli by providing much drier conditions than most South American amphibians in the hobby are accustomed to.
The keeper should spray the enclosure just enough to keep the substrate moist. Being fossorial, the ambient humidity does not need to be monitored quite as rigorously. The Chaco region experiences low humidity (and sometimes frosts) during the dry season and over 70% humidity (and 35°C+ temperatures) in the wet season. This makes Cranwell’s horned frogs extremely adaptable and an average of 50% humidity to be optimal, though experienced keepers could experiment with some seasonal fluctuations. For keepers who have a different species of horned frog, humidity should be kept consistently higher, with a heavier spray and moister substrate.
Cranwell’s horned frogs are often observed in ephemeral (short-lasting) pools but never in semipermanent ponds. It is, therefore, a good idea to provide a large shallow water-bowl, although an aquatic area is not necessary. This contrasts the horned frogs’ closest cousins, the Budgetts frogs (Lepidobatrachus sp.) which will spend long periods submerged in water. Horned frogs will often use a water bowl to assist with shedding, so keepers should be vigilant to remove shed skin and other debris from the bowl.
Let There Be Light
As a burrowing species, horned frogs would generally receive only a small amount of sunlight, but in an open savannah environment, these short bursts will still provide some UV. Therefore, providing Ferguson Zone 1 lighting is likely to be beneficial. However, keepers should be considerate in providing some cover from the overhead light in the form of sturdy, broad-leaved plants (real or artificial). This is especially true for keepers of albino horned frogs, as these animals will typically be more sensitive to UV. As well as providing shelter, keepers can reduce the UV exposure (by around 30-40%) of their animal by using a mesh cover on the top of the enclosure.
Another common mistake is the use of heating. Because horned frogs need to be kept warmer than the average home, heat mats are commonly used to push the temperature up. However, the unnatural concept of heating from below means that burrowing species, who often use their digging behaviour to avoid the hot sun, end up digging towards the heat. Instead, if a heat mat is used, it should be applied to the side of the enclosure. Heat cables can also be used strategically to provide heat from different angles. Of course, a well-insulated glass enclosure with a lighting fixture will naturally raise the temperature, so new keepers should record the ambient temperature of the enclosure for a few days prior to acquiring their frog.
It should also be noted that substrate should be very deep. Most keepers will know that this is a burrowing species, but substrate should allow for the frog to bury itself completely out of sight if it wishes to. Although they will typically keep their mouth and eyes above the ground looking for a tasty morsel of prey, these slow-moving animals will dig deeper to avoid predators and the extra few inches of substrate will ensure the frog feels safe and secure. Previously, coir was the substrate of choice but as a material that can easily dry out, get stuck to the animal’s skin and potentially be ingested, a bioactive forest substrate such as Bio Life is much more appropriate.
Voracious Predators
Horned frogs will eat almost any living thing they can fit into their mouths. Although limited, literature on this species’ wild diet has discovered that several frog species are commonly eaten (Leptodactylus bufonius, Physalaemus biligonigerus and P. albonotatus). In captivity, a diet comprised mostly of insects would be preferable. However, keepers have an excellent opportunity to provide some enrichment through a varied diet.
As a food-motivated species, one of the best ways to interact with a pet horned frog is through treats. Shrimps, chopped fish, appropriately sized rodents, earthworms, waxworms, silkworms, etc will all be readily accepted. Of course, these foods are generally high in fat, so ensuring they are spaced out through an appropriate feeding schedule is important. Young frogs should be fed daily, but as they grow, this frequency should be reduced. It should also be noted that if the temperature of the enclosure is much cooler than 25°C, it can prevent young frogs from feeding. Therefore, it is vital to ensure all the conditions are met, before introducing a baby horned frog into an enclosure.
Some keepers also opt to feed their frogs in a separate enclosure to avoid the animal ingesting substrate. While this is not entirely necessary (especially if the frog is tong-fed), it does offer a new safeguarding measure and allows the keeper to do a quick visual health check. Furthermore, bathing the frog for 5 minutes in room temperature, de-chlorinated water will allow the frog to remove its skin, as well as any debris that might be stuck to them and prompt them to go to the toilet without creating a mess in their water bowl. This is a popular feeding routine for breeders or those with lots of animals to maintain.
Horned frogs can eat vertebrates of their own size due to their disproportionate head and incredible bite force. In a 2017 study, Lappin et al discovered that horned frogs (Ceratophrys sp.) bite with ~5 to 500N of force at the jaw point. This is much more in line with amniotes (reptiles, birds and mammals) than amphibians. It also suggests that primitive amphibians such as the menacing devil frog (Beelzebufo ampinga), thought to be the largest frog that ever lived, would have had a similar bite force, and fed on hatchling dinosaurs. Aside from its 41cm length, the devil frog is morphologically very similar to today’s horned frogs, but as its remains have only been found in Madagascar, scientists are still trying to join the dots.
Maintenance and Care
During the cold months, horned frogs may go into estivation. While this can be avoided by maintaining consistent temperatures (around 26°C), new keepers should be aware that this is completely normal. The frog will develop a hardened layer of skin to retain moisture through the winter months and should not be disturbed while they are in this phase. Gently increasing the temperature and humidity over a few days should bring them out of estivation. New keepers should also be warned that frogs also shed their skin naturally as they grow.
Non-bioactive enclosures should be cleaned entirely every week, digging out all substrate to remove any waste. Horned frogs will frequently use their burrows and water bowl to defecate and so keepers should keep to a strict cleaning schedule even if they cannot see any obvious mess. Bio-active enclosures may require slightly less maintenance, but the horned frog’s ravenous appetite adds a new challenge of keeping the clean-up crews alive. In this case, picking a clean up crew too small to be considered a snack is a good idea (i.e springtails or white dwarf isopods).
As ambush predators, horned frogs are some of the few species that may benefit from a smaller enclosure, particularly as juveniles. Introducing a baby horned frog into a very large terrarium with just one or two prey items can mean the frog could be waiting a very long time to eat. This can be avoided by feeding in a separate enclosure, or by ensuring the main enclosure is size-appropriate for the animal to feed. Compressing substrate so it is firm enough to ensure small prey items remain on the surface is also a good way of supporting a frog’s feeding behaviour.
Breeding Horned Frogs
Despite their abundance in the hobby, horned frogs are notoriously difficult to breed. They generally experience mass-breeding events in the wild, waiting for heavy rainfall before bursting into a breeding frenzy to make the most of the newly formed pools of water across the Chaco. Breeders are required to delicately adjust temperatures across the year, before creating a rain chamber for the frogs.
Due to the nature of their breeding habits, the frogs will typically spawn between 1000 and 2000 eggs each which usually hatch in less than 4 days. Not only will adult frogs eat the spawn, meaning they must be isolated immediately, but the tadpoles are also highly cannibalistic. To combat this, the breeder must feed the tadpoles several times a day with aquatic foods (bloodworms, tubifex, chopped earthworms, etc), before isolating each individual tadpole as soon as possible. Responsible breeders should be aiming for 0 preventable mortalities which is extremely difficult if that person has a day job during the breeding season.
After 3 to 5 weeks the tails are absorbed, and the frogs become fully-fledged froglets. Providing the breeder is successful and manages to raise 1000 healthy frogs, finding a home for them will no doubt prove difficult. Most horned frogs in the UK are imported from breeding facilities overseas, which have already invested hundreds of thousands of pounds into equipment, full-time staffing, building a reliable network of customers and essentially refining their breeding process. For the hobbyist, the financial outlay of equipment for every life stage of the frogs, time and resources to prevent cannibalism, space for a reservoir of neutral, toxin free water and the ability to find 1000 new homes, means that horned frogs are simply not a viable breeding project.
Morphs and mutations
The Cranwell’s horned frog has many morphs and colour mutations. With only a handful of breeders producing many thousands of horned frogs, the availability of these morphs frequently changes. Albinos are generally the most readily available morphs and from this, there are several ‘strawberry’, ‘apricot’, ‘pineapple’ etc morphs that all exhibit a yellow/pink colouration. Of the green varieties, there are ‘peppermint’ which are readily available as well as the more recent ‘emerald’ and ‘teal’ varieties in the US. From the peppermint colouration also comes more vibrant blues, as well as ‘chocolate mint’ which (of course) combines brown patterning with a peppermint colour base.
As well as a whole spectrum of colour morphs, some mutations are also prevalent in horned frog line breeding. The most common of these is the ‘four spot’ which is aptly named due to its almost patternless body, possessing just four spots behind its eyes. ‘Samurai’ line frogs are also frequently available in the UK. These animals have gold outlines around their patterning and are some of the more sought-after frogs within the hobby.
Another popular morph that has recently seen a dip in availability is the fantasy horned frog. This is a hybrid between the Cranwell’s and the ornate horned frog. They have the iconic horns and bulky size of C. ornata whilst possessing the colouration and spaced patterning of C. cranwelli. Exotics Keeper Magazine advises against the hybridisation of species. Fantasy horned frogs, whilst generally healthy animals, cannot reproduce which suggests we should avoid crossbreeding where possible.
The Perfect Pet?
Horned frogs are easily some of the best pet amphibians. Not only do their natural behaviours lend them to being a manageable pet, but they are readily captive-bred and there is an excellent support network of dedicated keepers for new hobbyists to engage with. Although there are still many mistakes that people can make, ensuring the keeper knows exactly which species they are buying, has already established an enclosure with reliable temperatures and humidity readings and is fully prepared to upgrade the enclosure frequently, horned frogs are an excellent entry-level amphibian. With breeders dedicating huge amounts of time and resources to produce animals for private keeping and medical research purposes, as well as various researchers delving into the natural history of these animals, horned frogs will undoubtedly remain a popular species and inspire new herpetoculturists for many more years.
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