The rain forest covers only 6 percent of the world's tropical areas, but they are home to more than half the species of animals in the world. Some of these animals go through metamorphosis, a development process with several stages before reaching their adult form.
Most invertebrates pass through metamorphosis during their life cycle, but some vertebrates, such as frogs, also go through this process before reaching adulthood.
Life Cycle of Animals
Animals that go through metamorphosis, by definition, change their form -- the root word "meta" means change, while the word "morpho" means form. Invertebrates including insects and spiders along with amphibians such as frogs and toads, grow by transforming during their life cycle.
For insects that go through a complete metamorphosis, they mature from an egg, to a larva, to a pupa, to an adult. Other insects go through what is known as incomplete metamorphosis. Typically, the immature forms look similar to the adult form but they lack wings. When fully mature, they are winged.
Most butterfly species live in the rain forest. A mere 11,250 acres of Ecuadorian rain forest has more species (676) than all of North America. Egg, larvae or caterpillar, and pupa or chrysalis are the stages of butterfly metamorphosis, before reaching the adult form.
Rainforest butterflies include the Blue Morpho, Owl butterfly, Periander Metalmark, Crimson-banded Black, Tiger Longwing and Tropical Milkweed.
Ants, Termites, Bees and Beetles
The majority of invertebrates in the rain forest are ants and termites.
More than 500 ant species were found in 15 acres of Malaysian rain forest compared with the total 700 species of ants found in North America. Ants, bees and beetles go through the same metamorphosis stages as butterflies.
However, the metamorphosis of termites is considered an incomplete process, because the animals do not go through the chrysalis stage. This is called hemimetabolism.
The Tortoise beetle, the ants of the genus Polyergus, the South American bee and the Cubitermes termites of Africa are some examples of insects that go through metamorphosis.
Grasshoppers and Dragonflies
Similar to termites, grasshoppers and dragonflies don't go through the chrysalis stage during their development. Instead, they pass through several nymph stages, when the young animals hatch already looking like an adult and change their external skeleton during growth.
There are more than 2,000 identified species of grasshopper in the rain forest, including species of the genus Rhachicreagra. The Nietner's Shadowdamsel, the Two-spotted Threadtail, the Jungle Threadtail and the Rivulet Tiger are some dragonflies found in the Sri Lanka rain forest.
Spiders and Scorpions
Rain forest spiders include many species of tarantulas, such as the Bird Eating Goliath, with a leg-span of 10 inches; the venomous Brazilian Wandering Spider; the white-and-black Tropica Tent-Web Spider; and various species of jumping spiders, such as the herbivorous Bagheera kiplingi, found in Mexico.
Although most species of scorpions live in dry habitats such as deserts, some species are adapted to live in the hot and humid rain forest. The mildly venomous Australian rain forest scorpion is an example. Spiders and scorpions go through an incomplete metamorphosis.
The other animals that go through metamorphosis besides insects and other invertebrates are amphibians. Frogs spend the early stages of their life cycle in the water as eggs and tadpoles. Through the metamorphosis, the exterior gills are replaced by lungs, back legs and front legs appear and the juveniles lose their tails.
In the rain forest, some frogs such as the Green and Black Dart and the Blue Dart have bright colors, which is an indication of their venom. However, some colorful species, such as the red-eyed tree frog, is not toxic to humans.
- Rainforest Alliance: Blue Morpho Butterfly (Morpho peleides)
- Rainforest Alliance: Red-Eyed Tree Frog (Agalychnis callidryas)
- Mongabay: Amazon Insects
- Space Radion Lab at California Institute of Technology: Where Are the Rainforests?
- Norwegian University of Science and Technology: Liocheles waigiensis