View Cart

Zoo-pedia > Care and breeding of Amazon Milky Frogs...

Care and breeding of Amazon Milky Frogs Phrynohyas resinifictrix

By Kevin Stevens - first published in the journal of the International Herpetological Society.

Introduction

The Amazon Milk frog is a beautiful species of treefrog that has only been available in the UK for a short period of time. The species has been available to keepers in other countries a little longer. They are of similar appearance to Whites treefrogs (Litoria caerulea) in their build, they are heavy bodied and stocky with a certain level of cute dumpiness. They are also of a similar adult size, around 6-10cm. The colours and patterns differ though, although variable, the majority seen in captivity in the UK are grey and black with a bluish tinge. They are exceptionally beautiful as babies, the grey is replaced with a silvery white. They have a white milk like (hence the name) secretion that is thought to be poisonous and used as a defence. The skin has a granular and bumpy texture.

First described as Hyla resinifictrix by Goeldi in 1907 and then reclassified as Phrynohyas resinifictrix by Lutz in 1973. They are sometimes referred to as Trachycephalus resinifictrix. Common names vary from Amazon Milk frog, Milky frog, Blue Milky frog, Gold Eyed Mission frog (Darrel Frost and The American Museum of Natural History) or various variations.

Distibution

A South American species found in areas below 800 m elevation from the Caribbean lowlands, from the llanos of Colombia through Venezuela, Trinidad and Tobago, the Guianas, south through the Amazon Basin of Ecuador and Peru to Bolivia and North Eastern Brazil (Darrel Frost and The American Museum of Natural History).

Captive care

We first came across this species in the flesh (so to speak) in Hamm, Germany at Terraristika in September 2003. An Eastern European breeder had several newly metamorphosed froglets of about 1cm in size. We acquired six, with a view of growing them to adults and having a breeding group of our own. Once home we set up a vivarium at the shop so we could show them off to customers. As this was the first time many UK keepers had seen them they were very popular and it was very tempting to sell them at the prices that we were being offered!

We used a glass vivarium made by Custom Aquaria measuring approx 45cm (tall) x 30cm x 30cm. A piece of 2cm Amphifoam was placed on the floor, shaped so that when providing a 2cm depth of water there was a land area and water area. We often use amphifoam for treefrogs as it allows quick and easy cleaning on a daily basis, i.e. tip out the water, rinse the foam and replace! Various branches, pieces of cork bark and artificial plants where positioned to allow climbing and hiding. The only access was from the top, and the lid was a piece of glass. The glass vivarium has a 3cm x 30cm mesh ventilation strip. No additional heating was provided, the room temperature at Coast to Coast Exotics is around 26-28C daytime, dropping to around 22C at night. I would highly recommend that a heater be provided by the average keeper to keep these kinds of temperatures. No lighting other than the counter and other close by vivaria lighting was provided. We tend to find most species of amphibians prefer subdued lighting. The frogs and their environment were sprayed daily with tepid water (all water is either stood for 24 hours or treated with Zoo-med’s Reptisafe). To begin with all ten were housed together, and as they grow they were split into smaller groups, housed in a similar manner as described.

As usual for froglets we realised the importance of getting the diet well catered for and also the correct supplementation. The bulking part of these young frogs diet was commercially available crickets, appropriate to their size. It is important to gut load the crickets. There are many products that will do this – we tend to use Bug Grub. This is a bran based cricket food that is loaded with vitamins and minerals that once inside the cricket is passed to the feeding frog. Nutrobal and Calypso Cricket dust is dusted onto the crickets in a 50/50 ratio. Food is given each day, but the two dusts are only used five days out of seven. Other foods used include fruit flies and various small insects obtained from sweepings. Sweeping is a technique of passing a fine net through long grass to catch the small insects that live there. Just make sure that the area has not been treated with pesticide! As the frogs grew they progressed to bigger foods, commercially available waxworms are devoured with relish! As adults even day old pinky mice will be taken. Other foods include earthworms and locusts. I personally do not like the use of mealworms as a food for amphibians. Supplements are dusted onto the food around three times per week for adults.

Once they were adult (they grew fast and were about full grown in a year) all six frogs were transferred to a larger glass vivarium. This is one of our corner vivariums, underneath our breeding group of Whites treefrogs. This vivarium measures 110cm (tall) x 90cm (wide) and 75cm (depth). Amphifoam, branches, artificial plants etc. were used, on larger scale, as when we housed the babies. A dull light is also provided, mainly to allow customers to see inside the vivarium. Obviously, as all the vivaria are in the same area, temperatures remain the same.

Breeding

We had spoke to several breeders by this time and had read some pieces of work on the internet about breeding this species. Apparently, in the wild this species only breeds in water that accumulates in the holes of trees. They are relatively easy to sex, males call and have nupital pads, and are usually smaller than females. We started to plan a similar rain chamber system as to what we have used for our Whites treefrogs. Our thoughts began to dwell on how we could provide artificial holes in trees, when, one day we came into the shop to find developing spawn and small tadpoles in the 2cm of water at the bottom of the vivarium! We were very pleased with this, but what did we do to stimulate them to breed? Or, contrary to what we had been told and had read, were they easy to breed and need no stimulus? I have to admit, that after analysing what we had provided for them we had managed to get them “in the mood” by neglect. Not gross neglect I hasten to add, but to explain, we later found that due to excessive workload (well that’s what they blamed!) my staff had not sprayed them down daily, and the 2cm of water had begun to evaporate. This in turn had created a dry atmosphere. When the mistake had been realised, water was replaced and topped up and after a prolonged spraying down of the environment that night they had spawned. We have repeated this since several times (always with success), a period of about four days of not spraying the vivarium and then a thorough cleaning out, topping of the water levels and then a thorough spraying down – hey presto frogspawn the next day!

Catering for the tadpoles (with notes to possible problem solutions)

Our first batch of tadpoles at first baffled us a little, there was spawn and small swimming tadpoles together within 24 hours of being spawned. We began to notice quickly that their growth rate was terrific. Much quicker than I had seen with other species of frogs. This continued with later spawnings too, the spawn could develop into small swimming tadpoles in around 24 hours. They progress onto algae feeding almost instantly, and then onto the usual later stage tadpole diet of animal matter with three or four days. The later stages take a little longer, but they still can be a fully formed land living froglet in three weeks!

Glass aquaria with a water depth of around 15cm at the deepest was provided for the tadpoles. Hygiene is very important as all tadpoles are messy feeders. Daily water changes are usually found to be necessary. Filtration of the water disturbs the tadpoles too much, so this method of keeping the water clean is not used. Water that has been stood for twenty four hours, or water treated with Zoo-med’s Repti-safe is used to ensure that chlorine problems are avoided. Water temperature is around 20-22C. As the tadpoles start to metamorphose a floating land area is provided, once the froglets have left the water they are transferred into similar vivaria as described for our original froglets.

This leads me to a problem we have encountered. The froglets often seem to be weak and not do well. There are no obvious symptoms such as often seen in Dendrobates (poorly developed hind quarters and limbs), but they tend not to thrive. I would suggest that out of a spawning of several hundred we would be lucky to get a couple of dozen to adulthood. I have spoke to several breeders and other keepers who do not seem to suffer the same problem. Possible solutions range from excessive water temperatures for the developing tadpoles (we have now tried lower temperatures with poor success for the tadpoles), tadpole diet low in multivitamins (we have tried using Nutrobal in the water) and that their diet overall is missing something and to use natural pond mud to replicate all the small organisms they would naturally feed on (we have tried this with similar poor results). We have since bought in Milk froglets not bred by us and have successfully got them to adulthood with nearly 100% success rate. This problem only seems to be with our own produced stock! Any suggestions would be gratefully accepted!

Conclusion

Phrynohyas resinifictrix seems to be an easy treefrog to cater for, in a similar ilk to a Whites treefrog. Breeding seems to be easily stimulated, but perhaps their reputation for being a difficult breeder in captive conditions stems from success rates of bringing the froglets up.

References

Frost, Darrel R. 2004. Amphibian Species of the World: an Online Reference. Version 3.0 (22 August, 2004). Electronic Database accessible at http://research.amnh.org/herpetology/amphibia/index.php. American Museum of Natural History, New York, USA.