Golden Mantella
Tagged: animal, animals, cat, insect, invertebrateMantella aurantiaca
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The golden mantella frog is only found in one small forest on the island of Madagascar. It is threatened by the destruction of its habitat and by the international pet trade in frogs. The golden mantella is one of a small group of frog species found only in Madagascar. It is brightly colored, poisonous, and active by day. It shares such characteristics with the poison-dart (dendrobatid) frogs of Central and South America. In evolutionary terms, however, the golden mantellas and poison-dart frogs are not related. The golden mantella thus represents an example of “convergent evolution” by which organisms come to closely resemble one another not as a result of common evolutionary ancestry, but through the action of natural selection (the survival of individuals best adjusted to their environment). The exact relationships of the mantellas are not clear. Some authorities put them in the large family Ranidae; others in a small family of their own: the Mantellidae. Like the poison-dart frogs, the mantellas acquire poisonous compounds, called alkaloids, from their insect prey. They incorporate the toxic substances into secretions made in numerous poison glands in their skin. Predators that attack toxic, brightly colored prey quickly learn to associate the striking color pattern with an unpleasant experience and thereafter avoid that particular kind of prey.
Terrestrial Mating
Unlike many frogs, mantellas do not mate in standing water. However, they need damp conditions to breed and consequently mate in the rainy season. Males call to females, producing a sound like a cricket’s chirp that consists of a series of notes, with three “clicks” in each. When a receptive female approaches, the male clasps her in a brief amplexus (mating embrace), during which the eggs are laid in hollows in the damp soil. There are suggestions that fertilization is internal, but mating has not been properly observed. The eggs are whitish in color, and there are between 20 and 75 in a clutch. They hatch after about 14 days; the tadpoles push their way up to the soil surface and then wriggle over the damp ground to a nearby pool. There they complete their development, emerging as tiny frogs about two months later. In contrast to the vivid adult coloration, newly metamorphosed golden mantellas are green and black.
A Race against Time
The golden mantella lives only in one small forest area between Beforona and Maramanga in western Madagascar. The forests of Madagascar have been largely destroyed. Trees have been felled over large areas to be exported as timber and to create land for agriculture. All kinds of animals that are unique to the island are threatened by such activity, and biologists are currently exploring the remaining forest fragments to catalog the endemic (native) fauna before it disappears. As a result of the intense exploration, a growing number of newly described Madagascan species, including mantellas, are emerging. A few years ago only three mantellas had been described, but the most recent analysis lists 12 species, all of which are listed by IUCN at some level of threat.
Golden mantella
Mantella aurantiaca
- Family: Ranidae/Mantellidae
- World population: Unknown
- Distribution: Eastern Madagascar
- Habitat: Deep leaf litter in wet tropical forests
- Size: Length: 0.8-1.3 in (2-3 cm)
- Form: Adults bright yellow, orange, or red; newly metamorphosed frogs green and black; black eyes
- Diet: Small invertebrates
- Breeding: Clutch of 20-75 whitish eggs laid in dark cavities on land; eggs hatch after about 14 days; tadpoles wriggle to small pools and emerge as tiny frogs about 2 months later
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