Originally published in the September 2013 edition of Reptiles magazine
The South American Horned Frogs (Ceratophrys) set themselves apart in the Amphibian hobby, with the trend for Hybrids & Colour Morphs – something usually frowned upon by Amphibian aficionados – could these frogs become the Amphibian keepers Leopard Gecko or Ball Python?
THE SPECIES CERATOPHRYS
The Ceratophrys genus consists of 8 species all restricted to South America and all sharing similar general appearance & a largely fossorial lifestyle.
The most commonly available species to the hobbyist is Ceratophrys cranwelli the Chacoan or Cranwell’s Horned Frog. Originating from the Chacoan region of Argentina, Brazil, Boliva & Paraguay it is to most a large and impressive looking frog attaining an average of 3-4 inches (8-10cm).
The second most commonly available species is the Cranwell’s closest relative Ceratophrys ornata the Bell’s or Ornate Horned Frog. Originating from Argentina, Brazil & Uruguay it’s range overlaps slightly with the most southerly part of the Cranwell’s range in the Pampean region of Argentina. Until the early 1980’s these 2 species were considered synonymous with one another and it is unknown if records for the species in Uruguay actually belong to ornata or cranwelli. Most specimens found in captivity are easily distinguished from cranwelli being generally a brighter, more colourful species in their standard form marked with deep greens & reds and attaining an average size of 4-6 inches (10-15cm).
The 3rd species seen with any regularity is Ceratophrys cornuta the Amazonian or Surinam Horned Frog originating from Amazonian Columbia, Ecuador, Peru, Venezuela, Bolivia, Brazil, Suriname & French Guiana. It is a mid-sized horned frog reaching 2¾ – 4¾ inches (7-12cm) and has a rather striking appearance with it’s wide head, long horns, and leaf mimicking markings. The base coloration can be a pinkish tan brown or beautiful light green.
In the last couple of years 3 other species have found their way into the market and look set to establish themselves as regulars in the trade in years to come these being Ceratophrys stolzmanni, Ceratophrys aurita & Ceratophrys joazeirensis.
Ceratophrys stolzmanni the Pacific or Stolzmann’s Horned Frog is a small species attaining just 2-2¾ inches (5-7cm) it has 2 distinct subspecies; C.s.scaphiopeza from Ecuador and the nominate C.s.stolzmanni from North-Eastern Peru. It is a rare species in nature but an explosive breeder a trait that has, thanks to the Ecuadorian Wikiri farm, resulted in large numbers of frogs making their way into the international trade. Their small size and attractive appearance should result in them becoming a popular choice for hobbyists with hopefully more regular availability in years to come.
The Wed’s or Brazilian Horned Frog (Ceratophrys aurita) hailing from South-East Brazil was for a long time hailed as the Holy Grail by ‘fat frog’ fanatics. Historic field reports of specimens reaching nearly 9-10 inches (22-25cm) were filling the mind with wonder and amazement but as is often the case these field records appear to have been either mistakenly attributed or incorrect. In 2010 The Frog Ranch in California introduced the first specimens of aurita to the American market but individuals of this line have yet to reach anywhere near the size speculated for this species.
The other species that has recently come to market is the Joazeiro or Caatinga Horned Frog (Ceratophrys joazeirensis). Due to the efforts of Philippe de Vosjoli et. al. a small number of individuals have been brought together and successfully bred and released to the hobby, hopefully future breeding will result in a significant captive population and reduced prices.
I should point out that at the time of writing this article there is still speculation over the exact identification of the animals currently being offered as C.aurita & C.joazeirensis with discussion & research on-going by their respective producers.
The other species in the Ceratophrys genus are the Ecuadorian Horned Frog (Ceratophrys testudo) & the Colombian Horned Frog (Ceratophrys calcarata) but sadly at present neither of these species are available in the trade. Ceratophrys testudo is simply unavailable in fact this species is currently only known from the original record for the species made in 1945 by Nils Johan Andersson.
It has been many years since I last saw Ceratophrys calcarata offered for sale, I am aware of a small number of relict individuals in the hands of European hobbyists and I’m sure the same can be said for the US. It originates from Columbia & Venezuela and is another small species similar in size to C.stolzmanni at 2-3 inches (5-7.5cm). Wild caught specimens were at one time a regular in the trade and it would be a nice thought that potentially through the efforts of hobbyists sharing these remaining individuals for stud purposes this once commonly kept species could be bought back to market as captive bred.
Although for the most part large bodied, these frogs are not overly active and can be maintained in relatively small enclosures. In fact, they often fare better in smaller spaces, especially when young. For the larger species I aim to provide an enclosure with a floor area of eight to ten times the frog’s size. This frog-to-floor-space ratio holds true for froglets as well as adults. This is very handy for breeders maintaining large numbers of adults and their offspring as they should be kept individually to avoid cannibalism.
Glass tanks or deep plastic tubs are best enabling the provision of a nice deep substrate in which to burrow. I prefer to use a free-draining substrate such as coconut-fibre, provided to a depth of 4-6 inches (10-15cm) and for the most part kept damp but not sodden. When using this type of substrate it is easier to maintain the correct moisture level than with peat or moss, this moisture control is especially important during periods of aestivation that I will discuss later.
As with all frogs a shallow water dish should be provided and kept as clean as possible. Cage decorations can be added if you so wish but will add more to your aesthetic enjoyment than to the environmental enrichment of the frogs. Being large, heavy & robust these frogs easily trample or unearth live plants so if you want to decorate the enclosure I would advise you go down the artificial route. About the only décor that may be utilised by the frogs are hides either of the pre-formed plastic variety or in the shape of arched cork and broken terracotta plant pots.
Daytime temperature should be maintained around 79-82°F (26-28°C) with a nighttime drop to around 75°F (24°C). Humidity should be kept at around 70% day and night with good ventilation.
Ceratophrys are ambush predators spending much of their time buried up to their eyes in the substrate waiting for an unsuspecting insect, frog, lizard, or rodent to pass by. Young Horned Frogs should be offered food daily; their diet should consist largely of live insects including earthworms, crickets, and roaches. Small live-bearing fish or mouse pinks may be fed from time to time to provide additional variety. Young frogs should be allowed to consume as much as they will take in a sitting, this may be several invertebrates or in the case of larger prey may only be a single item.
Young frogs grow quickly and have the potential to reach adult size in as little as six to nine months, due to this rapid growth they require a good supply of calcium & vitamin D3 in the diet to ensure healthy bone development. Ideally a good quality calcium and multivitamin supplement should be dusted over food at every other meal. You may cut down the frequency of supplementation as they mature.
Adults can be fed less often than froglets, only requiring a good meal every few days, they will often feed whenever they are given the chance and as such it is easy to over feed. A healthy adult should be slightly longer than it is wide. Suitable food items for adult Horned Frogs include Locusts, Roaches, & Lob Worms. Fish or pre-killed rodents may be offered occasionally but frogs can become addicted to mice often refusing to then feed on invertebrates. Adults maintained on a varied diet should only need supplements on one feeding every other week.
Be careful when putting food into the enclosure, these frogs are aggressive feeders, they have strong jaws and a row of very sharp maxillary teeth running along the upper jaw with a pair of large odontoid projections on the lower jaw designed to hold their prey. A bite from a large animal will hurt and often draws blood.
Wild caught animals, particularly of C.cornuta, can often be difficult to get feeding and many keepers resort to force-feeding which can cause more harm than good. Stubborn animals that initially refuse to feed should be placed in darkened terraria kept warm and humid, several large crickets or medium sized roaches should be placed with them and left undisturbed. Usually this is enough to get them settled and begin feeding, if they continue to refuse food and show signs of weight loss they should be tested for parasites and treated accordingly.
THE BASICS OF BREEDING
Ceratophrys are explosive breeders spawning in temporary water bodies formed by heavy rains following a dry period of aestivation. They have evolved to produce large numbers of highly carnivorous & cannibalistic offspring that feed on tadpoles of other species sharing the same breeding pools as well as each other and develop quickly to ensure as many as possible get out of the water before the pools dry up.
In order to breed Horned Frogs in captivity you must recreate the cycle experienced in the wild. This means a period of aestivation where the frogs are kept cooler and relatively dry encouraging them to burrow down and enter a state of dormancy, followed by a stint in a rain chamber to encourage spawning. Some species of Ceratophrys are easier to breed than others, females of some species can be picky about their partners and some require more conditioning than others do. For best results use fully mature animals of at least 18 months of age with good body mass, having multiple males per female helps to encourage calling and competition in the rain chamber and an increased likelihood of a successful spawning.
A successful spawning can result in several thousand eggs that hatch within 24 hours, tadpoles will begin to cannibalise as soon as they are free swimming and unless you keep on top of feeding numbers will quickly dwindle. Food for the tadpoles can include black worms, tubifex & frozen bloodworms. With heavy feeding a large amount of waste is produced and so the water will need filtering and changing frequently. With a good care regime the tadpoles will continue to develop quickly and the first froglets can be ready to leave the water in as little as 3 weeks at a little under an inch.
HYBRIDISATION: FACT NOT FANTASY
Although hybrids are for the most part frowned upon by Amphibian hobbyists it has become common place for breeders of Ceratophrys to create interspecific hybrids often labelled Fantasy Frogs. These hybrids tend to be hardy individuals and often feed better than their parent species, they are for the most part mules with odd chromosome counts and thus incapable of producing fertile offspring.
The only commonly produced of these hybrids is the D&M’s Fantasy (C.cranwelli x C.cornuta) originally named after it’s creators de Vosjoli & Mailloux it is now normally referred to simply as the Fantasy Frog. The combinations of parental coloration and patternation traits gained from C.cornuta and the intermediate traits exhibited in horn length & build make for a rather attractive ‘species’. This enhanced appearance coupled with attaining the same size as it’s parent Cranwell’s it has become a popular and relatively inexpensive option to the hobbyist looking for something a little different.
The ‘Orwells Fantasy’ (C.cranwelli x C.ornata) is not often available as it is unpopular with both producers and hobbyists. Due to the difficulties experienced in production it demands a higher price for individuals that can be relatively difficult to distinguish from one or the other parent species. When this cross is produced resultant offspring have a tendency to show real hybrid vigour with one of the most voracious appetites and attaining a larger size than their parent species.
C.cornuta x C.ornata is another hybrid that suffers some problems in it’s production making it non-viable for most breeders to produce. They are similar in appearance to the C.cornuta x C.cranwelli cross but with some of the red coloration gained from the Ornate.
With the recent addition of C.joazeirensis to the hobby hybrids involving this species have already started to appear and I’m sure it won’t be long before we see all sorts of other Fantasy Frog hybrids being created with the addition of C.aurita.
LIFE IN GLORIOUS TECHNICOLOR
The world of colour morphs probably isn’t anything new to most of you reading this, I’m sure you’re all familiar with the multitude of Leopard Gecko & Royal Python morphs on the market, ranging in value from less than a wild type to many thousands of pounds. Well now the Pacman looks set to become the Amphibian hobbyists challenger in the high stakes game of genetic roulette.
Since the introduction of the albino Cranwell’s Horned Frog by The Frog Ranch in 1992 the development of colour morphs has slowly gained speed. Some of the most commonly seen line-bred albino strains include the ‘Lemon’ which concentrates on bringing out the light yellows, and the ‘Lime’ strains that are developed from the green tinge often seen in standard albinos. Some of the newer strains of albinism concentrate on bringing out the darker tints of oranges & reds, having developed from the ‘Peach’ to the Apricot’ and now into the new ‘Strawberry’ strain.
Some of the other line-bred strains of the Cranwell’s Horned Frog concentrate on developing the natural green coloration that has at present culminated in the Peppermint line developed by Nuance Herptile Farm in Japan. Juveniles of this line typically show pastel greens with a blue tint, and in some individuals reduced markings. The development of these green strains has also allowed the subsequent development of colour morphs in the Fantasy Hybrids with high-green animals being produced dubbed ‘Apple Green’ and the intermediate ‘Tri-colour’.
Line breeding in C.ornata has concentrated on creating redder individuals to the point where we are now seeing scarlet red examples almost completely lacking in the standard green background coloration.
One of the biggest pitfalls in developing colour morphs of Ceratophrys is the difficulty in choosing which animals should be held back for future breeding due to the large number of offspring produced, and the fact that individual animals can change colour and patternation quite dramatically from froglet to adult. The other big factor being their cannibalistic nature, their siblings could gobble any abnormally coloured tadpoles up long before they begin to develop their coloration. However dealing with species that have such fast rates of growth and with the ability to produce hundreds of offspring per breeding it was only a matter of time before unusual genetic anomalies started to turn up. Nuance in Japan have produced a ‘mutant’ strain that appears to combine traits of amelanism, erythrism and possibly some degree of axanthism creating a wild variety of unusual colour combinations. Including almost pure white amelanistic albinos, the ghostly grey erythristic ‘Phantom’, and pied examples combining areas of standard coloration with patches of amelanism.
It will be interesting to see how these mutations develop down the line and the weird and wonderful colour combinations that could be produced. What ever happens the future certainly looks colourful for the Ceratophrys collector.