Green Mantellas, called Midori-Ade-Gaeru in Japan, are small frogs, although they are larger than many other members of the mantella genus. Mantellas are very popular among frog enthusiasts.

A diurnal animal, the Green Mantella does most of its hunting during daylight hours and will spend most of the day hunting. They eat insects and other small invertebrates, but mealworms are difficult to digest. They enjoy humidity and warm temperatures. Their call is short, consisting of two short clicks. They are terrestrial frogs, meaning they live on the ground rather than in trees. They lay eggs in damp hollows near water. They have a complicated mating ritual. They enjoy immersing themselves in water. Mantellas are fairly messy, considering their small size - one mantella is capable of producing great amounts of waste. Males can be aggressive with other males while defending their territory. Males of the species outnumber females by a two to one ratio.

Green Mantellas are quite small, reaching only 28 to 35 mm in length, although they are the largest of the Mantellas. They appear in two color varieties. The most common is gray-green with stippled back legs and dark flanks. The other is a little bit smaller and a beautiful, vibrant lime green color with black flanks. Both color varieties have dark bands around the top lip and the venter has black and blue spots. Female Green Mantellas are slightly larger than males, and their snout is squarer.

The Green Mantella is found only in the very north of Madagascar, in the region known as Montagne de Francais. They have only been observed in the wild once, in 1988. Because the Mantella is very popular, they are becoming very rare in the wild. The care and breeding requirements must be carefully studied before purchase of a mantella, as they can require a great deal of commitment.

Despite their small size, Mantellas need a fairly large living area. Because they are territorial animals, more than one frog in a small area can cause undue stress. The door must be tight-fitting and escape proof, because mantellas are so small they can fit through most cracks. The substrate can be sphagnum or java moss, with several logs, rocks, and branches to climb on and nest under. A shallow water pan should be placed far away from the light. Mantellas require a fairly moist environment, which can be encourage by plants and a damp sponge of some sort, as well as semi-frequent misting.

Because Mantellas are diurnal, the daytime light and temperature is important. They should be provided with around 10 hours of light in the winter and 12 to 14 hours in the summer. Daytime temperatures should be between 72 and 78 degrees Fahrenheit, and should not drop below 68 degrees at night.

Mantellas should be fed insects, as they are insectivorious in the wild. They can eat crickets, fruit-flies, waxworms, small flies, spiders, beetles, moths, caterpillars, and spiders. They should receive a variety of insects, and they all must be pesticide free. Because they hunt throughout the day, mantellas should be given their food at several times during the day rather than all at once.

Mantellas can be very difficult to breed in captivity. The chances of a successful breeding are much higher if there are two or three males for every female. The male calls until the female approaches. The actual mating is usually done under a rock or log. The eggs are then deposited in a moist area, but never actually in water. They are usually laid in the nighttime. They are relatively large and encased in a clear gelatinous coating. Green Mantellas can lay as many as 100 eggs at a time, although the exact number varies. In captivity, many eggs are infertile. The eggs should be misted regularly. They hatch into well-formed tadpoles after between two and six days. The tadpoles should be near enough to water to wriggle free. Mantella Tadpoles metamorphosize after between 45 and 360 days. Even in clear water, there is often a 50% mortality rate.