|Binomial name||Mantella betsileo|
|Average Size||2.8 cm (1.1 in)|
|Average weight||1.3 grams|
|Distribution of species||Eastern Madagascar|
The brown Mantella, Mantella betsileo, is a species of large Mantella native to northeastern Madagascar. It is one of the less colourful species, although unlike the related Haraldmeier's Mantella it is toxic. Mantella betsileo are kept as pets, though they are not as common in captivity as other Mantellas.
The brown Mantella is one of the less-toxic of the Mantellas. Its skin secretes pumiliotoxin C, the least toxic of the pumiliotoxin types found in other mantellas and in South American poison dart frogs. The brown Mantella only contains a small amount of pumiliotoxin and as such it is not as brilliantly coloured as other mantellas, although it may attempt to startle predators by "flashing" them with the stripes on its flanks. This usually causes predators to hesitate long enough to allow the frog to get a head start and escape. If trapped, the brown Mantella uses its poison for self-defense. When wild specimens are touched, painful muscle cramps and temporary local paralysis occurs. Eating a brown Mantella causes more serious symptoms, and most predators learn to avoid them after experiencing their toxins.
Pumiliotoxin is deadly in high concentrations. Pumiliotoxin is weaker than allopumiliotoxin and especially batrachotoxin, with a lethal dose of 2 mg (M. betsileo carries about half of a milligram). There are three different types of this toxin A, B and C. Toxins A and B are significantly more toxic than C. Pumiliotoxins affect the body because they interfere with muscle contraction in the heart and skeletal muscle. The toxin works by affecting the calcium channels. Some of the symptoms of pumiliotoxins are partial paralysis, having difficulty moving, being hyperactive and in some cases it can result in death.
Description EditMantella betsileo is a fairly large species of Mantella. Males range fron 2 to 2.25 centimetres long, whereas females may reach 2.5 to 2.8 centimetres long. It is a fairly slender Mantella. The spine is sometimes visible beneath the skin, giving the frog the appearence of being underweight, a feature that it shares with Mantella ebenaui.
The flanks of M. betsileo are black or deep brown, and the legs are normally dark grayish-brown but may be black in some specimens. The flanks also bear two white stripes that are used to confuse predators and warn them of the Mantellas' toxicity. The dorsum may be wood brown, chocolate brown, or earthy brown depending on locality and the belly is black with white spots.
The brown Mantella is primarily terrestrial, rarely leaving the ground. However, occasionally it may climb onto low-growing plants to catch food, and males may do so to call to females.