CHILEAN HELMETED TOAD/CHILEAN WIDE MOUTHED TOAD (CALYPTOCEPHALELLA GAYI) CARESHEET
Note that this is based off my experiences with a singular specimen which I got roughly a year ago. This is not meant to be professional, just an anecdote of what I have found to work as there is little info on these guys.
these are ancient ass frogs. the genus apparently dates back to the cretaceous. they are wrinkled, primordial, and green. They are also the second largest frog on the planet, potentially able to grow up to around 2 pounds. As far as I know, they are farmed for food in their native lands (Chile) and the sudden influx of juveniles popping up in various online exotic animal stores probably originated from these frog farms. I would assume if they were just catching them in the wild you would see mature adults being sold alongside the juvis, for much higher prices, as is the case with bullfrogs, cane toads, and giant malaysian toads. If true this is a good thing as it means captive breeding is feasible. I assume there's at least a couple people out there who have accumulated little herds of these imports and are planning to try and breed them.
As for the care, they are basically a cooler water budgets frog. They are pretty much aquatic, but poor swimmers. Mine is almost always in the water, though it is always resting on the bottom or on the stems of the tank's vegetation. When it was younger it would occasionally rest on land, under a section of cork bark. A land area with a hide should be provided, but the tank should mostly be water.
The ideal setup would be a large tub/aquarium with a sand/gravel substrate, sloping so as to create a gradient. Most of the water should be shallow, but with a deeper area if the frog really needs to cool off. Unless your frog tank area gets extremely cold you do not need any kind of heating. There should be a plant light of sorts (I use Barina T5) and live aquatic plants.
I find live plants are very important for frogs, especially ones that need significant water features. With amphibians i have found that the closer to their natural habitat, the better, as opposed to the laboratory style setups that wirk for snakes. I have only ever had health issues with animals that were kept in plastic plant/paper towel style setups. Anyways, plants provide cover and help keep the water clean. I use duckweed, water lettuce, pothos, elodea+hornwort, water hyacinth, and some random ass plant I got from a nursery.
In nature I would assume calyptocephalella spend their time in the shallows, concealed in thick aquatic vegetation, waiting for food. This is what mine does and it is perfect. Having a nice, densely planted tank reduces the cleaning you need to do and helps prevent stress in the frog. You can use floating cork flats/rounds for additional shelter, mine enjoys these as well. I would avoid any pointed/sharp edged rocks or driftwood as these can cut the soft frog.
Here is my current setup. It is a bare-bottom plastic tub, with ample vegetation and cork bark. The filter is rated for 30 gallon aquariums. The land area is a reptile water dish filled with dirt, sat on top of one of those plastic rectangular snake hides. The water is around eight inches deep. I don't use a lid (probably should) as the frog is not exactly a jumper, more so a sitter.
From what little I found these frogs do not like moving/running water. You should use a canister filter (the one with the intake+outake tubes), preferably rated for a higher capacity than that of your frog's tank. Aquarium filters are rated for fish tanks. Most fish make tiny stringy poops. These frogs however are superior organisms and make large muddy shits, like turtles. Water quality is very important as amphibians are very sensitive to dirty/polluted water. The tank is cleaned every week or two. I leave a bit of the old water to ensure beneficial microfauna sticks around. pH is kept around 7.0. I have a small aquarium fan on the left side of the tank to keep the water cool, but I doubt it accomplishes much. Both the intake and outake tubes are submerged beneath the surface to prevent water movement.
The water is probably fine without any heating/cooling unless surrounding temperatures reach one extreme or another. My tank's water stays high sixties to low seventies, Fahrenheit. The surface temperatures are usually low to mid seventies. These frogs seem to prefer a cooler climate and temperatures should not go above the upper seventies. If it does (happened once or twice) it is not the end of the world, but should be avoided. Having the option to retreat to deeper water could be a lifesaver for your frog here. Mine was originally kept in very shallow water only a couple of inches deep: , though with the frog's greater mass and the warmer weather I have since changed it.
Feeding is simple. After a few days of getting used to captivity my frog started eagerly taking various live and dead foods from tongs. The bulk of the diet should be insects, but I give frozen thawed mice and silversides as treats. Rodents are fatty and probably extremely rare in their natural diet, so they should only be fed sparingly. I feed mine every other day or so. These are greedy fat frogs and thus fun and easy to feed.
One final thing is that mine croaks very frequently, despite seeming to be a juvenile. It is currently about the size of my palm and hasa grown maybe a few centimeters in length since i got it. Perhaps it is a small male going through frog puberty, perhaps the croaking is more territorial in nature. It is not particularly musical, being a repeated squeaky/rubbery grunt of sorts.
TLDR
-keep at room temp (low to mid seventies)
-pH 6.5 to 7.0
-planted aquatic tank with shallow areas to rest, surface cover, and small land area. Filtered but no water movement
-good eaters, diet should be insects with occasional frozen thawed fish or rodent
-build it a shrine. offerings must be blood, and painful.
