Basic Information and Natural History
Species: Golden Mantella (Mantella aurantiaca)
Size: Around 1.0 inch (2.5 cm) as adults. Male golden mantellas are smaller and more streamlined in appearance.
Appearance: Uniformly yellow to orange-red in coloration, with red flash marks at the insertions and joints of the legs. Captive-bred golden mantella frogs may lack red flash marks. Their bright colors warn predators of their poisonous skin secretions which in the wild are sequestered through arthropod prey. Frogs in captivity are not poisonous.
Distribution, Habitat and Behavior: Golden mantella frogs have a tiny distribution in east-central Madagascar, where they live in humid forest around small seasonally-flooded breeding ponds. For almost half the year they may be dormant and inactive, awakening during the breeding season when rains arrive. Male frogs descend forested hills to breeding ponds as they flood and begin calling to attract mates and defend territory. Eggs are laid on land and are presumably flushed into ponds during rains, where tadpoles develop.
Availability: Sporadically available, the golden mantella was once common due to an abundance of wild-caught imports that flooded the pet trade in the 1990’s and early 2000’s. Fortunately for wild populations, trade has since been restricted, although wild-caught frogs are still available from time to time. It is much preferable to source frogs directly from breeders. Golden mantella frogs are not especially difficult to breed in captivity and can be found for sale online with some patience, or sometimes through local herpetological societies and at herp shows, and it is worth searching for captive-bred stock to avoid fueling the wild trade in an endangered species.
Care in Captivity
Housing: Although golden mantella frogs are small, they do best when provided with plenty of room. Males are territorial and often fight over potential breeding sites and feeding areas. For a group of six to nine adult frogs, a 20 gallon long aquarium that measures 30 inches long by 12 inches wide by 12 inches high (76 cm by 30 cm by 30 cm) is enough space.
Although a bioactive terrarium is often the preferred method for keeping golden mantellas, it is easier to monitor frogs in simpler setups. A substrate of pea gravel or expanded clay pellets, over which fiberglass windows screen cut to the footprint of the terrarium is set, followed by a layer of moist sphagnum moss or a soil blend works well. Leaf litter should be scattered about on top. Live plants can be planted directly in the substrate or kept in pots. In addition, shelter such as driftwood, cork bark, or coconut huts should be provided. Simpler setups involving moist paper towels or a thin layer of only moss and no plants can also work, but care should be taken to change the substrate often in these simpler housing styles.
Temperature and Humidity: Maintain a temperature between 68°F (20°C) and 74°F (23°C) during the day, with a drop to around 60-65°F (16-18°C) at night. Occasional days outside this range are fine, but extended periods of hot temperatures may contribute to health problems. Maintain constant high humidity by misting the terrarium with water daily. During warmer weather mist heavily and on colder days mist less, with an ambient humidity level of 70-100% usually being fine. Weeks or months of dryer conditions followed by heavy misting may help stimulate breeding.
Water: A shallow water dish or area in the terrarium should always be available. If tap water is used, make sure to treat it with tap water conditioner to remove chlorine, chloramines and heavy metals. Mantella frogs are not especially adept at swimming and so the water area should not take up a large part of the enclosure.
Diet: Golden mantella frogs are able to eat large insects compared to many other similarly-sized amphibians. Most eagerly chase any insect that is 1/4 inch (6 mm) in length or less. Week old crickets and flightless fruit flies can make up the majority of their diet. Most pet stores do not carry fruit flies or tiny crickets, so it’s best to either culture them yourself or order them from a large commercial supplier. Other food items that can be offered include aphids, roach nymphs, springtails, rice flower beetle larvae, small wax worms, and termites. Use a variety of different feeders to avoid nutritional deficiencies.
The amount of food that is offered depends on how large the feeder insects are and how often you are feeding the frogs. Using somewhere between 5 and 15 food items every two days per frog is a good place to start. This can be adjusted based on body condition. Often weak or small males will be bullied out of food by stronger ones, so it is a good idea to feed in multiple areas of the cage rather than in one main spot or territory. During cool temperatures, golden mantellas may only need to be fed weekly in small amounts. High quality vitamin and mineral supplements should be dusted onto the feeder insects every few feedings. Juvenile frogs should have their food dusted at every feeding.
Male golden mantellas can be distinguished from females by their call, streamlined appearance, smaller average size, and presence of visible femoral pads on their inner thighs. It has been suggested that golden mantella frogs breed more readily in captivity when kept in groups with multiple male frogs for each female.
It can be helpful to cycle frogs through a cool and/or dry period for up to three months of the year to mimic the conditions that they would experience in the wild. During this time, the lights can be cut back to around ten hours per day, the temperature should rarely rise above 72°F (22°C), misting should be reduced to a couple times a week, water levels lowered, and the quantity of food and feeding schedule decreased. This winter period can often be stressful, and care should be taken to carefully monitor all frogs in the terrarium during it. If a frog shows signs of poor health or seems to be losing substantial weight it should be removed to a new enclosure and isolated from the rest.
After two or three months of these harsh conditions, the photoperiod, temperature, and feeding schedule can be returned to normal or increased. Heavy feeding and lots of moisture are key to stimulating reproduction. Mature female frogs often begin to swell with eggs a few weeks after the cool/dry period has ended. The day before a gravid female frog deposits her eggs, their spherical shapes can clearly be seen outlined in her skin.
Eggs are normally deposited in moist burrows or crevices, although occasionally they will be laid in the open. It’s common for only part of a clutch of eggs to be fertilized by a male, or for none to be fertile at all. Eggs should be removed from the terrarium three days after they have been laid, and should be placed into a separate tadpole rearing container on top of a clump of moss so that they are not submerged in the water but just touching the water’s edge.
Over the following week, small white tadpoles can be seen developing inside of the egg mass. The eggs should be kept in a covered container to maintain high humidity. Anywhere from three to twelve days after fertilization, the tadpoles will have developed enough to break out of the egg. Some people have suggested that the longer the tadpoles remain in the eggs the stronger or larger the tadpoles will be, and because of this the eggs should not be sprayed with water to help the tadpoles break free from the egg jelly.
Tadpole Care: For the first few days after leaving the egg, the tadpoles do not need to be fed. Raise tadpoles communally in large plastic containers with a clump of java moss or a clipping of pothos. The plants will give the tadpoles an area to hide and help maintain water quality. For the first couple weeks, the water depth should remain shallow, between 1 and 2 inches (2.5 cm and 5 cm). As the tadpoles grow, the water depth can be increased to around 4 inches (10 cm). Water quality is extremely important. Tap water can be used from some areas, provided that it is treated with a tap water conditioner to remove chlorine, chloramines and heavy metals. Alternatively reverse osmosis (RO) water can be reconstituted with minerals and made appropriate for raising tadpoles using aquarium products.
The water temperature should stay between 65°F (18°C) and 78°F (26°C), but should be controlled so that it doesn’t fluctuate too much in too short a period of time. A mixture of foods including algae such as spirulina and chlorella, fish flake, bloodworms, daphnia, shrimp pellets, and catfish wafers can also be used. The tadpoles should be fed daily or every other day, but make sure not to overfeed or the water will spoil.
Tadpoles from the same clutch of eggs often develop at different rates. Generally, the first tadpoles develop front arms and emerge from the water around eight weeks after the eggs are laid. Tadpoles continue to complete metamorphosis over the next four to eight weeks. Once the first tadpoles show signs of their front arms developing they should be moved to a separate container that has a water depth of half an inch (1.3 cm) or less. The new container should also have a tight fitting cover. Once the tail begins to be absorbed, the little frogs should be moved to a terrestrial setup with moist paper towel as a substrate. In addition to the substrate, there should be a hiding area such as a pothos leaf, fake plant, dried oak leaf, or simply a crumpled up piece of moist paper towel. I keep my young mantella frogs either individually in standard 16 oz. deli containers or in groups of two to five in plastic containers that measure 5 inches long (13 cm) by 5 inches wide (13 cm) and 3 inches (7.5 cm) high. They can also be raised in groups in large terrariums, but must be fed very heavily to ensure all frogs have access to food.
Froglet Care: As soon as the tail is fully absorbed the tiny (7-10mm) bronze colored froglets will require lots of tiny insects to feed on. Drosophila melanogaster and hatchling crickets are accepted by most froglets, although some of the smaller frogs won’t be able to handle insects this large. For frogs that are too small to eat fruit flies or crickets, small clumps of wet leaf compost from outside can be placed into their deli containers to introduce insects. Springtails and aphids are also two great food sources to use for young golden mantella frogs.
At between two and three months of age, the frogs can be moved to larger containers with moist sphagnum moss or soil as a substrate and pieces of bark, rocks and fake plants as hiding spots. The juvenile frogs should be cared for in exactly the same way as the adults except for the frequency with which they are fed. Young frogs should always have food available to them in small quantities. Use a varied diet that is supplemented with appropriate calcium and vitamin supplements. Three to eight months after emerging from the water, most of the frogs will have completely developed their orange adult coloration. Occasional frogs won’t complete their adult coloration until they are as old as ten months.