That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Long overshadowed by the wildly popular dart poison frogs, the equally tiny and beautiful mantella frogs are finally coming into their own. While most are spectacularly colored, the Baron’s Painted Mantella (Mantella baroni) seems to eclipse all others, at least in my opinion. It is also the largest species commonly available (and the second-largest known), a fact that renders it both more eye-catching and a bit easier to provide with a varied diet.

 

Description

Among the mantellas, Baron’s Painted Mantella is exceeded in size only by the Green Mantella (Mantella viridis)…but at 0.88-1.2 inches in length, it is still quite diminutive. Clad in a spectacular array of contrasting colors, with orange, black, yellow and green appearing to varying degrees on different individuals, it is well-named!

 

This species is easily confused with the Malagasy Painted Mantella (M. madagascariensis); tips and photos that will help you to distinguish the two can be found in the article linked below. Unfortunately, both species have long been imported and housed together, and hybridization has likely occurred. Both are often offered for sale as “Painted Mantellas”

 

Baron’s Painted Mantella is closely related to and sometimes confused with Cowan’s Mantella (M. cowani, please see photo); natural hybridization has been documented in wild populations.

 

Range and Habitat

The 16 frogs in the genus Mantella (family Mantellidae) are largely confined to Madagascar, although several species inhabit Reunion and other nearby islands. Baron’s Painted Mantella is found in eastern-central Madagascar, from Fierenana to Andringitra. Three national parks are located within its range, so some populations may be spared the declines faced by other species. However, Chytrid infections have recently been documented in Madagascar, so strict protection and captive breeding efforts are essential.

 

This species seems somewhat adaptable as to habitat, although specific populations may have evolved a dependence on local conditions. Barron’s Painted Mantellas have been found in swamp forests, stream side thickets within arid habitats, bamboo groves, rain forests, and re-vegetated agricultural areas, at elevations of 900-3,600 feet above sea level.

 

Toxins

Brilliant colors warn predators that Baron’s Painted Mantellas are protected by powerful skin toxins. Entomologists at the California Academy of Sciences have discovered that mantellas derive these toxins, or alkaloids, from their diet. A primary source of the toxins, at least for some species, is an endemic ant, Anochetus grandidieri. In an amazing example of parallel evolution, 13 of the toxic compounds found in Mantella skins are also utilized by unrelated dart poison frogs, which feed upon unrelated ants, in Panama!

 

In addition to utilizing ants as an alkaloid source, Baron’s Painted Mantella is also believed to rely upon certain mites and beetles.

 

The Terrarium

Once they have settled in, you can expect to see many interesting behaviors from Baron’s Painted Mantellas, as they are active by day, quite bold, and are always foraging, exploring, interacting, and otherwise “on the go”. They do best in terrariums stocked with live ferns, bromeliads, Philodendron and other plants. A densely-planted tank will provide you with many interesting observations, as the frogs will feel secure and behave normally.

 

A pair or trio can be kept in a 10 gallon aquarium; larger tanks can support small groups. As males defend specific territories, mixed groups must be given plenty of room and cover, and watched carefully.

 

Mantellas spend most of their time on land and drown easily. One-half inch of de-chlorinated water should be provided in a shallow bowl or sloping pool.

 

Baron’s Painted Mantellas can scale glass and will escape through even the tiniest of openings, so the terrarium’s cover must be secured with clips.

 

Substrate

A mix of top soil, coconut husk and commercial rainforest substrate works well. I like to use sheet or sphagnum moss over the substrate, to help retain moisture.

 

Light

Low levels of UVB light may be of some benefit.   The Zoo Med 2.0 Low Output UVB Bulb is ideal.   UVA may help to encourage natural behaviors, including reproduction. A number of UVA-emitting bulbs are now available (please post below for further information).

 

Heat

Baron’s Painted Mantellas generally dwell at high elevations or deep within forests, and require cooler temperatures than one might expect. They fare best at 68-76 F. Most individuals become stressed when temperatures exceed 80 F, and death may occur with 2-3 days of sustained high temperatures.

 

Due to the variety of habitats and elevations to which this species has adapted, individuals originating from different areas of the range may vary in their temperature needs. Further research is needed – please post your observations below.

 

Humidity

Humidity levels of 80 -100% should be maintained by keeping the moss layer damp and spraying the terrarium heavily. Small misters are especially useful in arid homes and dry climates.

 

Feeding

A highly-varied diet is essential. Crickets alone, even if powdered with supplements, are not an adequate diet. As the Baron’s Painted Mantella is quite small, providing a proper diet requires careful planning. Monitor your frogs closely – underfed individuals will exhibit protruding hip bones and flat stomachs.

 

The diet should be comprised of as many of the following food items as possible (please see the articles linked below for further information on rearing and collecting small insects):

 

Tiny flies, gnats and moths

Flightless fruit flies

Pinhead/10 day old crickets

Hatchling mantids (see article below)

Springtails

Termites (please see article below)

Flour beetle larvae

Ants: experimenting required, as some species are rejected

Aphids: tiny insects that colonize plant stems.

Field Plankton: insects gathered by sweeping through tall grass with a net (also great fun for kids and adults alike, please see photo!)

 

Baron’s Painted Mantellas have large appetites and should be fed every day or two. A free-living Brown Mantella was observed to eat 53 ants in 30 minutes!

 

Important food supplements include Zoo Med ReptiCalcium or a similar product (most meals) and a vitamin supplement (ReptiVite with D3) 3 times weekly.

 

Breeding

Males issue their “single-click” call from concealed positions by day. Unlike most frogs, amplexus is dispensed with. The eggs, which may number over 100, are deposited on land, with the tadpoles being washed into nearby waterways by rains. Captive breeding needs more attention from private keepers and zoos – please write in for further information.

 

Handling

Baron’s Painted Mantellas are tiny, quick, and easily-stressed. They are best considered as animals to observe, not handle, and should be moved by being urged into a plastic container.

 

Individuals that feed upon typical captive diets are not likely able to synthesize skin toxins, but imported individuals will retain them for some time. Other skin secretions transferred to wounds, eyes, or the mouth may cause irritations.

 

 

Further Reading

Collecting Feeder Insects

Differentiating the Two Painted Mantellas

Tulane University researchers have published an important study concerning captive frog nutrition that should be of interest to all amphibian and reptile keepers. A colony of Strawberry Poison Frogs (Oophaga pumilio) was maintained on a diet comprised of fruit flies. When carotenoids were added to the fruit fly diet, the frogs produced significantly more eggs, and a greater number of tadpoles survived through metamorphosis. The Vitamin A deficiency found among some of the animals was also reversed.

 

Nutritional deficiencies are common in both private and public amphibian collections, partly because of the limited dietary variety we are able to provide. Adding carotenoids (which are pigments produced by plants) to the diet of feeder insects may be a simple means of improving health and reproductive output – especially important in these times of unprecedented amphibian declines. Please see also the links under “Further Reading” for other articles I’ve written on supplementing cricket diets with carotenoids and Vitamin A deficiency in frogs.

 

Carotenoid Function and Sources

Various plant pigments known as carotenoids are responsible for the yellow-orange color of egg yolks and skin among a huge array of animals. They also play a role in neonatal health, benefit the immune system by acting as antioxidants and function in the reproductive system. Animals cannot manufacture carotenoids but rather must obtain them from their diet.

 

In the Tulane University study (Zoo Biology, V32, N6), the fruit fly medium’s carotenoid content was increased by the addition of Spirulina, red phaffia yeast and powdered marine algae. Studies have also shown that the provision of fruits and vegetables increases the carotenoid content of crickets; please see links below.

 

Effects on Reproduction and Survival

Sixty-two pairs of Strawberry Poison Frogs were included in the study. The increased tadpole survival was attributed to higher quality eggs being produced by female frogs. Infertile eggs, which are deposited by females as food for their tadpoles, were also believed to be of higher nutritional value following carotenoid supplementation.

 

A number of the animals were found to suffer from a Vitamin A deficiency. This condition was reversed over the course of the study. Many animals convert carotenoids to Vitamin A, so it is theorized that the addition of carotenoids to the fruit fly medium was responsible. As many frog enthusiasts know, the all-too-common condition known as “Short Tongue Syndrome” has been linked diets low in Vitamin A. If your frogs or toads are having difficulty catching insects, please see the link below, or post here for further information on this disorder.

 

Further Reading

Adding Carotenoids to Cricket Diets

 

Carotenoid Supplementation may Brighten Frog Colors

 

Do Your Frogs have Trouble Catching Insects?

The discovery of a new frog is always an exciting event, but the species revealed in this month’s issue of Zoo Keys is especially so. The colorful, entirely-aquatic Telmatobius ventriflavum was found in a small stream along a major highway 3,900 feet up in the Peruvian Andes. It is related to a unique group of frogs, the best known being the bizarre, “push-up performing” Lake Titicaca Frog (Telmatobius culeus).   I was fascinated by the huge, baggy-skinned Lake Titicaca Frogs resident at the Bronx Zoo (the only ones in captivity) as a child – and due to their 30 year lifespans, I was lucky enough to work with those same individuals once I began my zoo-keeping career!

(Please see the article linked below for more on this amazing frog). The Lake Titicaca Frog’s newly-discovered relative promises to be just as interesting – and, it seems, is similarly threatened with extinction.

 

A Strange Frog in a Harsh Habitat

The new found frog sports the odd (some say “un-nerving”) upwardly-directed eyes typical of the other 62 members of the genus Telmatobius (similar, in my mind, to those of the more familiar Buddget’s Frog) and a beautiful, bright yellow to orange abdomen.

 

The only known population occupies a narrow stream of the Huaytara River, located in a valley on the Pacific slope of the Peruvian Andes. Herpetologists were surprised by its discovery because the site is near a major highway, and in a region that has been well-studied. The frog’s bright coloration might also have been expected to draw attention. Furthermore, a completely aquatic frog was not expected in this habitat – a dry, shrub-studded alpine grassland known as the Puna. The region receives a bit of rain from January to March, after which it remains bone-dry, and it has few resident amphibians.

 

Threats: Chytrid, Dams and Isolation

Because the stream in which T. ventriflavum lives is separated from other suitable habitat by desert-like grasslands, the species is assumed to be endemic to the immediate area. The stream has dammed, but it is not known if this negatively affects the population (but it’s a pretty safe bet that it does!).

Unfortunately, some of the frogs and tadpoles that have been examined were found to harbor Chytrid fungus, which has been responsible for scores of amphibian extinctions worldwide. So far, nothing is known of the fungus’ impact on the population, but herpetologists are not optimistic. In Ecuador, 3 related species have been wiped out by chytridiomycosis, the disease associated with this fungus.

 

As T. ventriflavum is already at risk due to its tiny range and the damming of its home stream, careful study of the population, especially as regards Chytrid infection, is being considered.

 

 

Further Reading

Lake Titicaca Frog Conservation

Original Article Describing the New Aquatic Frog

 

 

 

Read More »

While working at the Bronx Zoo, I had the good fortune to breed Kihansi Spray Toads – an endangered species that gives birth to fully-formed toadlets – and the amazing skin-brooding Surinam Toad. Yet these are but two examples of the amazing diversity of odd frog breeding strategies, none of which resemble what might be called “normal” frog behavior! Among the world’s 6,400+ frog species, we find tadpoles that eat bark, their mother’s eggs and even their father’s skin, along with parents that carry eggs or young in skin pouches, vocal sacs and even stomachs. None, however, were known to give birth to live tadpoles. As you’ll see below, a herpetologist’s extremely lucky catch, at just the right moment, changed that recently – one can only guess at what will come next!

 

Strange Frog in a Strange Land

The Indonesian island of Sulawesi, located between Borneo and the Philippines, is home to some of the world’s most unique and (to most of us) unexpected animals. From invertebrates to mammals, the island’s fauna is “rule-breaking” and astonishing (take a look at the Sulawesi Black “Ape”, pictured here). So the UC Berkeley biologists working there recently were well-used to surprises. But when a herpetologist grabbed at a frog and came up with a handful of tadpoles as well, he knew that new ground had been broken.

 

Fanged Frogs

The frog in question, Limnonectes larvaepartus, had been collected before, but has only now been recognized as a new species. Endemic to Sulawesi, it belongs to a little-studied group known as the Fanged Frogs. Armed with sharp bones that project from the lower jaw (similar to the odontoids borne by Horned Frogs and African Bullfrogs), male Fanged Frogs battle one another, presumably for mates and territory.

 

Internal Fertilization and Live Birth

But where Limnonectes larvaepartus is concerned, peculiar dentition is only the beginning of the story. Following the timely capture of a female in the process of giving birth, it was determined that this new species also employs a new (to us, anyway!) form of reproduction. It is the only frog known to produce live tadpoles rather than eggs or small frogs. What’s more, fertilization is internal – a strategy used by only 8-10 of the world’s 6,455 frog species (including the USA’s Pacific and the Rocky Mountain Tailed Frogs; please see photo). The new species is described in the journal PLOS One (12-31-14, Iskander et al; see link below).

 

This discovery may help herpetologists to understand the evolution of the amazing diversity of Fanged Frogs on Sulawesi and elsewhere in Southeast Asia. Many more than the currently described 62 species are expected to be found, and as with all creatures on Sulawesi, they likely hold wonderful surprises for us.

 

Natural History of the New Species

We know very little about Limnonectes larvaepartus. There is some speculation that males may guard the tadpoles, but this remains to be confirmed. Females seem to rely upon small forest pools in which to deposit their tadpoles. This may be an attempt to reduce the threat of predation by larger relatives that inhabit nearby streams, but further research is needed.

 

Learning More About Amphibian Breeding Strategies

I can’t seem to stop writing about the amazing breeding strategies of frogs, caecilians and salamanders. Please see the articles below for more on wood-eating tadpoles and others. The article first describing Limnonectes larvaepartus is also linked.

Tree-Dwelling Tadpoles that Feed Upon Bark

Skin-Eating Tadpoles

Novel Reproductive Mode in a New Species of Fanged Frog

 

The Argentine, Pac Man or Ornate Horned Frog (Ceratophrys ornata) may be the world’s most popular amphibian pet. Beautiful and “charmingly” pugnacious, Horned Frogs require relatively little space despite their “salad bowl” size, and may live to age 20 or more. In a close second among frog fans is the massive African Bullfrog, Pyxicephalus adspersus. These brutes, which can live past age 50, are resilient beyond belief – one was observed downing 17 hatchling spitting cobras, and during droughts they can remain dormant for 10 to 12 months!

 

In the following article I’ll compare Horned and African Bullfrogs in terms of their habits, activity levels, and care needs, so that you’ll be able to choose the species that best suits your interests and frog-keeping skills. Detailed care information is provided in the articles linked under “Further Reading”; as always, please also post any questions or observations you may have.

 

Handling Your Pet Frog

Both Horned and African Bullfrogs have powerful jaws equipped with bits of bone that extend up from the jaw. These “teeth”, technically known as odontoid structures, can inflict serious wounds. Even after years in captivity, an instinctive feeding response will cause frogs to bite fingers moved within range.

 

Fortunately, it is a simple matter to safely pick up either by grasping it behind the front legs. However, they should be handled only when necessary, and then with wet hands, so that you do not remove the protective mucus from their skin. Wash well after handling any animal.

 

Activity Levels

Neither is overly active, but each has fascinating behaviors (please see articles linked below). Both will feed by day, but may become more active after dark. In order to observe them at night, you can equip the terrarium with a black or red reptile night bulb (frogs do not sense the light produced by these bulbs).

 

Life Span

The published longevity for an Ornate Horned Frog is just short of 15 years, but there are unofficial reports of individuals approaching age 23. African Bullfrogs are among the longest-lived of all amphibians, with a 51-year-old individual holding the record.

 

Breeding Potential

Both are bred by commercial dealers, but reproduction is not common in home terrariums. However, given suitable space and proper pre-conditioning, either species may surprise you with thousands of eggs…and the tadpoles are as rabidly carnivorous as their parents!

 

Cost

The cost of ownership of each frog is about the same. Neither requires UVB exposure, and they do fine with similar diets, terrariums and heat levels.

 

Terrarium Size (single adult)

African Bullfrogs and Horned Frogs are “sit and wait” predators, and as such are relatively inactive. A 20 gallon aquarium (or a similarly-sized plastic tub) will accommodate an average adult, but a 30 gallon tank will be “appreciated”. Males, the smaller sex, have been successfully kept in 15 gallon aquariums.

 

Light and Heat

Neither frog requires exposure to UVB light.

 

Both African Bull and Horned Frogs fare best at temperatures ranging from 72 F on the cooler side of the terrarium to 85 F at the warmer. Reptile heat pads are ideal as heat sources, but are best located along the sides of the terrarium. When placed below the tank, there is a chance that your frog may burrow down and come in direct contact with overly-hot glass. Incandescent bulbs, night bulbs, or ceramic heaters may also be employed, but beware of their drying effects.

 

Frog Diet

The dietary requirements of the two species are identical.

 

Both require a great deal of calcium, especially as they are growing. Whole fishes and, to a lesser extent, pink mice, are ideal calcium sources. Pink mice may be offered once each 7-10 days, or omitted if fish are consumed regularly.

 

Crickets alone will not supply adequate nutrition. Minnows, shiners, earthworms, roaches, and crickets can make up the bulk of their diet. Crayfishes, butterworms, silkworms and other invertebrates should also be included regularly.

 

Food (other than pinkies and fish) should be powdered with Zoo Med ReptiCalcium plus D3  or a similar product. Vitamin/mineral supplements such as ReptiVite should be used 2-3 times weekly.

 

Health Concerns (Pet and Pet Owner)

African Bullfrogs and Horned Frogs are equally at risk from the following health issues. If proper care and diet is provided, both will prove to be extremely hardy and long-lived.

 

Ammonia toxicity is the most frequent cause of death. Ammonia is released with waste products and is rapidly absorbed via the skin as frogs soak in water or rest on the substrate. Ammonia can prove fatal in short order, so be sure to have someone clean the terrarium frequently when you are away from home for extended periods. Generally, water should be changed daily, and always treated with a chlorine/chloramine remover. Unclean conditions can also result in a bacterial skin infection known as Septicemia or “Red Leg”.

 

Intestinal impactions resulting from substrate ingestion are sometimes encountered (both species). This problem can be avoided by the use of cage liners, or by feeding your frogs in large bowls, via tongs, or in a bare-bottomed enclosure.

 

Calcium deficiencies and other diseases related to poor nutrition are common among frogs maintained on crickets and mealworms alone. Please post below for further information.

 

Salmonella bacteria, commonly present in reptile and amphibian digestive tracts, can cause severe illnesses in people. Handling an animal will not cause an infection, as the bacteria must be ingested. Salmonella infections are easy to avoid via the use of proper hygiene. Please speak with your family doctor concerning details, and feel free to post below if you would like links to useful resources.

 

 

Further Reading

African Bullfrog Care

An Appetite for Cobras: Huge Bullfrog Meals

Horned Frog Care