ReptiFlow

Care sheets

Amphibians

Pacman frog

Ceratophrys cranwelli

Photo: Cranwell's horned frog · Diberri and Celgeofrog · CC BY-SA 3.0 · Changes and credits

These guides provide general husbandry information and do not replace veterinary assessment. If your animal shows symptoms or its condition worsens, contact a veterinarian experienced with exotic animals.

Care sheet sourcesJosh’s Frogs — Ceratophrys cranwelli: species and careTree of Life Exotic Pet Medical Center — Ceratophrys careDayna Willems, DVM — Aurora Animal Hospital: Pacman frog care (PDF)Frogfather — Ceratophrys: floor area and husbandryNotes on Ceratophrys cranwelli — ontogeny and ambush-site selectionAquarium Dietzenbach — C. cranwelli breeding accountTrudeau et al. — Amphibian reproduction studyAZA — Amphibian Husbandry Resource Guide: quarantineBaines et al. 2016 · UV-Tool, species tableBaines 2024 · UVB lighting for reptilesMerck Veterinary Manual — Proximate Analysis of Whole PreyArbor View Animal Hospital · Axolotl lightingArcadia · Crepuscular species, local basking UVICDC — Reptiles and Amphibians: hygiene and cross-contaminationMerck Veterinary Manual — Management and Husbandry of Reptiles: quarantine
Temperatures
Warm zone
28–29 °C · air, warm area
Cool zone
24–28 °C · ambient air
Recommended enclosureFloor ≥ 60 × 45 cmone adultLength × depth × height
Humidity60–70%; damp substrate and ventilated air
Adult sizeFemales up to approximately 13 cm; males smaller (C. cranwelli)

Description

Ceratophrys cranwelli is a terrestrial frog from the South American Gran Chaco. Its rounded body, very broad mouth and prominent eyes give it the appearance behind the name “pacman”. It buries itself with mainly the head exposed and captures prey by ambush; females are generally larger than males.

LifespanOften 5 years or more; 8–10 years is reported

Behaviour

A powerful-biting predator that often remains buried. Suitable for observation, not recreational handling.

Housing together

Keep one frog per enclosure: cannibalism is a risk even between the same species.

Enclosure and climate

Provide deep soft bedding for burrowing, damp without pooling, a shelter and shallow water with easy exit. Remove chlorine and chloramine before wetting bedding or filling the dish. Avoid gravel and minimize easily swallowed material.

Night 22–24 °C. These are air values, not basking surfaces. Do not combine this regime with temperatures from different protocols.

Setup

Prepare new water in a dedicated container and treat chlorine and chloramine before using it for dishes, substrate or misting, following product instructions. Have dedicated soft-tipped feeding tongs ready.

Warm area, cool area and hides

If heating is specified, place it at one end and distribute hides between that area and the cool side. Choose openings and internal space suitable for the body; after adding bedding, check that entrances remain clear. Set the dish on a stable base and leave routes between retreats; use low supports only where suitable for the species.

Burrowing and furnishing stability

Secure rock and platform supports to the floor before adding substrate to the specified depth. Leave a continuous digging area and remove material beside bases as a test: furnishings must remain supported. Complete the digging layer before adjusting lamp heights, as it changes the height the animal can reach.

Testing and access

Connect specified heat sources to compatible thermostats and guard against contact. Secure probes according to device instructions; measure air at resting sites and heated surfaces separately with independent instruments. In housing with water, also check water temperature and quality: one zone’s thermostat does not control the others.

With the complete enclosure running, record day and night readings and compare them with the sheet. Test doors, cable openings and cleaning access, keeping vents clear. Change one variable at a time and recheck after each adjustment.

Lighting and UVB

Ferguson zone not assigned with sufficient precision to this taxon.

At the exposed position aim for approximately UVI 1–2, measured at the back or head. The animal must choose its exposure and reach UVI 0 retreats. This local target differs from the Ferguson ecological band and should not be maintained everywhere throughout the day.

UVB is recommended at an intensity appropriate to the species, with the option to withdraw from the light. Evidence of its necessity varies between animals: assess exposure alongside diet and species identification.

UVA: the precise requirement is not established for this entry; no separate UVA source is prescribed. Evaluate illumination, retreats and life stage together.

Linear UVB tube with reflector. Indicative UVB percentage stated on the lamp: 2–7%; final selection depends on UVI achieved at the actual distance.

For maintenance, a cycle of approximately 12 hours of light and 12 hours of darkness can serve as an initial reference. Use a timer to switch lights off at night, and keep retreats available so the animal can withdraw from light during the day. Adapt day length to species and origin, following the specific guidance for seasonal care and breeding.

Lamp-to-back distance: internal mounting and above meshInternal lampLamp above mesh30 cm40 cmd = source-to-back distance, not source-to-floor distance
Example with height 60 cm and animal height 25 cm. Not to scale: distances describe layout without guaranteeing UVI or a safe clearance for every lamp. Check the model used, mesh and all reachable points.

Light in the animal’s daily life

The practical recommendation explicitly includes C. cranwelli but does not assign a Ferguson zone. Maintain cover allowing burrowing and rest outside the beam; do not brightly irradiate the entire surface.

An example layout in the enclosure

The sheet does not establish one minimum height. To explain mounting alone, imagine lighting supports 60 cm high: this illustrative height does not set minimum housing dimensions. Aggregated entries require species identification first.

In a wooden enclosure with internal lighting, imagine the tube 55 cm above the floor and the back or head at 25 cm. The geometric distance is therefore 30 cm. The branch or platform lies below animal height, according to body size. Place lighting over one side, with a route to fully screened retreats.

In a glass enclosure with a mesh roof, retain the same animal height and imagine the tube 5 cm above the mesh: distance becomes 40 cm. Mesh attenuates UV variably; ordinary glass roofs block UVB. Increasing the percentage alone is insufficient: measure beneath the mesh and adjust height, output or layout as needed.

These distances describe the example, not a safe clearance for every lamp. Select the source and adjust mounting until approximately UVI 1–2 is measured at animal height in the exposed position. Also respect the minimum clearance specified for the model used. Recheck with furnishings, guards and mesh installed, including the highest reachable points and animal growth.

Choosing and checking lighting

First define the patch that should illuminate the whole body and the route to a screened retreat. For a broad patch, select a linear tube with reflector; consider a compact only if its useful patch covers the body and leaves an accessible gradient. Check model, output, reflector and mounting distance, then compare measured UVI with the species target. Label UVB percentage alone cannot determine distance and intensity.

The decisive check uses a UVI meter facing the source at animal height. Check the centre and edges of the exposed patch, the highest supports and retreats, which must allow withdrawal from UV. Repeat after moving equipment, changing lamps and plant growth. Without a meter, use the manufacturer’s instructions and measurements for the exact configuration, including safety clearances.

When UVB or UVA are absent

When keeping without UVB, D3 must be supplied through a complete diet or species-appropriate supplementation. Calcium alone does not replace D3. Check existing amounts in prepared diets and multivitamins before combining products; dosage also depends on diet and cannot be derived from lighting hours.

UVA has no dietary replacement. Maintain appropriate illumination and photoperiod without adding an intense source to compensate for unverified information: amphibian exposure must be evaluated by species and life stage.

Humidity and ventilation

Check bedding beneath the surface, not only the hygrometer. Keep it damp without saturation; promptly remove waste and contaminated bedding. Misting does not replace ventilation. Measure near hides without letting the hygrometer touch wet bedding, and also inspect substrate beneath retreats. If readings stay outside the specified values, check blocked vents and standing water before adjusting water input; recheck after the change.

Feeding

Offer Ceratophrys cranwelli varied invertebrates with appropriate supplementation. An ambush predator: continued striking does not prove hunger. Rodents are not needed as a routine food.

Recommended foods

The tiers describe dietary use: rotate foods within each tier rather than treating them as an absolute nutritional score.

FoodDietary roleBenefits and limitsPreparation
Crickets and locustsMain choicesSupply protein and encourage hunting; calcium is low relative to phosphorus, so preparation and supplementation are needed.Use captive-bred insects and gut-load them as described below. Select suitably sized feeders, place the meal’s batch in a clean container and apply a thin calcium coating immediately before offering them.
Feeder roachesMain choicesThese feeders provide a useful second protein source for rotation, but do not constitute a complete diet or replace calcium supplementation.Offer well-fed soft nymphs sized to the mouth; avoid excessively hard adults.
Earthworms from controlled culturesMain choicesSoft prey with a generally more favourable mineral balance than unsupplemented crickets; particularly useful for amphibians. They are not a reason to eliminate all variety.Rinse and cut only if required for mouth size. Avoid dyed fishing bait, cultures on contaminated manure and collection from treated soil.
Waxworms, mealworms and superwormsOccasionalFat-rich larvae concentrate energy and often contain little calcium: use as a small part of variety, not the sole food.Replace part of the meal instead of adding them to a full ration. Avoid hard or oversized larvae for small animals.
Wild insects, fireflies and contaminated preyAvoid / not a stapleMay carry pesticides, parasites or toxins; a healthy appearance does not establish safety.Use traceable feeder cultures; do not collect insects beside roads or treated gardens.

Comparable nutritional values

Protein, fat, calcium and phosphorus are percentages of dry matter, excluding water; dry matter itself is a percentage of fresh weight. These are reference analytical values compiled in a clinical table, not guaranteed contents of your batch or a universal ranking. Age, rearing, feeding and supplementation change composition. Do not compare them directly with fresh-food percentages or already diluted prepared diets. Comparable numbers are not provided for other foods.

InsectDry matterCrude proteinCrude fatCalcium / phosphorusCa:P
Adult house cricketAcheta domestica32% of fresh weight62.6% DM20.4% DM0.3 / 1% DM0.3:1
Migratory locustLocusta migratoria31% of fresh weight67.5% DM14% DM0.1 / 0.7% DM0.14:1
Mealworm larvaTenebrio molitor32.8% of fresh weight52.8% DM36.1% DM0.3 / 0.8% DM0.37:1

DM = dry matter. Ca:P describes calcium relative to phosphorus before supplementation: a protein-rich feeder may still be calcium-poor. Offered portions remain those for this species and life stage.

Meals by age and size

Stage and sizeFrequencyAmount per meal
Newly metamorphosed: tail absorbed and terrestrial feeding establishedDaily, small portionsPinhead crickets or other microfeeders in small batches; count catches for about 5 minutes. Do not leave large crickets with newly emerged froglets.
Growing juveniles and subadultsDaily, moving to alternate days as growth slowsInitial trial portion: 3–5 small insects, one at a time. Count those eaten in about 5 minutes; stop when interest wanes rather than continually refilling. Adjust the count to actual prey size and growth.
Adults with slowed growth2–3 meals weeklyInitial trial portion: 3–5 small insects, one at a time. Count those eaten in about 5 minutes; stop when interest wanes rather than continually refilling. Adjust the count to actual prey size and growth. A suitable earthworm can replace part of the insects in species accepting it.

Adjusting portions

To assess the portion, compare the amount and type of food eaten with growth and body condition. Weekly weighing of juveniles and monthly weighing of adults helps follow the trend. Adjust the ration gradually when growth or reserves require it; reduce it if body condition indicates excess weight or leftovers remain. Investigate unexpected weight loss or abnormal swelling rather than addressing it only with more or less food.

Preparing and offering meals

Prepare insects during the 24–48 hours before feeding: keep them in their culture container with a complete feeder diet and safe hydration. Check access to food and water and remove spoiled leftovers. Then select feeders of the specified size and prepare only the batch to be offered. This step, called gut-loading, improves prey quality; bran or potato alone do not correct deficiencies.

At feeding time the prey should be easy to swallow. As an initial guide, choose insects no wider than the space between the eyes, then adapt size to the mouth and the animal’s response. Offering them individually or in an escape-resistant dish lets you see actual intake and remove leftovers.

Use clean equipment and water treated for chlorine and chloramine for tongs, bowls and rinsing; avoid soap residue. Offer near the animal without making it swallow substrate.

Calcium and vitamins

Immediately before feeding, lightly coat low-calcium insects with phosphorus-free calcium: they should remain visible, without clumps. Common insects often have an unfavourable calcium:phosphorus balance; rotating them alone does not correct it.

Choose one supplementation programme: plain calcium for ordinary meals and a species-appropriate multivitamin at its labelled feeding intervals. Record the product and its existing D3 and vitamin A; do not add a second dose to meals using a combined product. With measured UVB, agree the oral D3 provision; product concentrations are not interchangeable.

For amphibians choose a product appropriate for vitamin A as well; beta-carotene alone should not be considered equivalent in every species. Therapeutic vitamin A doses require a veterinarian.

Daily care

First days

Before arrival, run the complete enclosure and check temperature, light and humidity at usable positions. Prepare water, retreats and first food. On arrival, follow a quiet routine for feeding, water changes and cleaning; record food offered, leftovers and weight. Delay unnecessary contact until the animal feeds regularly and moves confidently. Weakness or weight loss warrants veterinary assessment.

Cleaning

Keep animals and equipment away from kitchens and food areas, use tools dedicated to each enclosure and wash your hands with soap and running water after handling animals, food, tank water or furnishings. Quarantine new arrivals separately and agree the duration and checks with a veterinarian before introducing them to established animals.

Handling

Use powder-free gloves moistened with treated water and support without squeezing. Keep contact brief. Permeable skin absorbs chemicals: soaps, creams and residues on hands are a risk.

Checks

Redness, lesions, weakness or labored breathing require an amphibian veterinarian.

Monitor weight loss, abnormal swelling and food refusal; do not confuse lethargy from unsuitable conditions with a normal seasonal pause.

Monitor appetite, weight and movement. Weight loss and weakness are not a normal settling stage.

Labored breathing, wounds, burns or marked stool changes need veterinary assessment; this sheet cannot establish a diagnosis.

Do not tear retained skin or indiscriminately raise temperature or humidity: verify measurements before adjusting the setup.

Breeding

Sex, maturity and readiness

Identify C. cranwelli: hybrids sold as “fantasy” frogs are not equivalent. Use well-developed, sexed adults; male calls and nuptial pads aid identification. A larger female can prey on an undersized partner.

Start a record for each breeding animal with identity, origin, documented age and previous weights. Compare the weight trend with growth and body condition; delay introductions for animals still growing rapidly, losing weight or recently acquired. Use stated ages as guidance alongside these checks. If sex cannot be identified reliably, obtain assessment by qualified personnel before pairing.

Preparation and seasonal cycle

Breeding follows the transition to the rainy season. Preparation requires food supplies and housing for hundreds of larvae; an improvised rain chamber does not replace conditioning. Do not induce dehydration or use hormones as a home procedure.

Before encounters, prepare and test offspring enclosures and have first foods available. Check records for regular adult feeding and good body condition, then verify access from exposed areas to retreats. If the species protocol includes seasonal changes, adjust settings gradually and record the response. Record night-time air, surface and egg temperatures separately, noting where each is measured. Keep water available throughout preparation.

Courtship and mating

The male calls and holds the female in amplexus, the reproductive clasp. Prepare an observable tank with shallow water, supports and an emerged exit; interrupt predation attempts without pulling apart clasped animals.

Spawning and egg collection

Eggs are scattered in water. After spawning remove adults, count or estimate the clutch and divide it among labelled containers. One captive breeding produced about 400 eggs: plan capacity before introductions.

Aquatic development and hatching

Development can be very rapid: hatching around 24 hours and forelimbs around 18 days are documented in one breeding setup. These are observations rather than a timetable transferable to every tank. Larvae are carnivorous and may cannibalise one another.

Use water treated for chlorine and chloramine at the same temperature as the original container. Guard intakes and keep movement gentle. Check eggs and water daily, remove dead material without breaking healthy eggs, siphon leftovers and faeces, test ammonia and nitrite and change water with prepared water as needed.

First meals and juvenile care

Offer tadpoles mouth-sized animal aquatic foods, distributed to reduce competition; remove waste and separate aggressors. When forelimbs emerge, prepare step-free exits. Rear newly metamorphosed frogs individually and introduce microinsects when hunting resumes.

Observe each larva’s feeding, growth and developmental stage daily, avoiding unnecessary capture for weighing. Also check water quality, injuries and size differences: a feeding group does not establish that every larva eats. Separate injured individuals or those excluded from food, and adjust space and diet as they develop. For forms that become terrestrial, prepare gentle exits and shelters before the transition to land.

Female recovery

After reproduction provide water and the usual balanced diet, initially in manageable portions; monitor weight, activity and return of appetite. Keep supplements and lighting consistent with the feeding guide. Avoid further introductions until the previous condition has recovered; later clutches may occur without another mating. Persistent straining, weakness or protruding tissue require veterinary attention, without squeezing the abdomen.

Equipment and example diary

Prepare rearing tanks, covers, a mature sponge filter or containers for regular water changes, water tests, a narrow siphon, thermometer and productive first-food cultures. The number of offspring raised must match the actual capacity to feed them and maintain clean water.

A consistent diary using actual dates helps follow reproduction in Ceratophrys cranwelli. Start with adult identity, weight and condition, then record observed encounters, laying or birth and development conditions. After emergence record the first meal actually accepted and each youngster’s growth while continuing to follow female recovery. Over time these records help identify your lineage’s pattern without turning approximate durations into deadlines.