Types of metamorphosis in insects, amphibians

1. Introduction to Metamorphosis

Metamorphosis is a biological process in which an animal undergoes a dramatic transformation in body structure after birth or hatching.
It is most commonly seen in insects and amphibians.
Metamorphosis is controlled by hormones, mainly ecdysone in insects and thyroxine in amphibians.
There are two main types of metamorphosis: complete metamorphosis and incomplete metamorphosis.

In complete metamorphosis, an insect passes through four distinct stages:
- Egg: Laid by the adult female.
- Larva: Worm-like stage, specialized for feeding and growth (e.g., caterpillar).
- Pupa: Resting stage where transformation occurs (e.g., chrysalis).
- Adult: Fully developed reproductive stage.
Examples: Butterflies, beetles, bees, flies, ants.

In incomplete metamorphosis, the insect undergoes three stages:
- Egg: Hatches into a nymph.
- Nymph: Resembles the adult but lacks wings and reproductive organs.
- Adult: Gains wings and reproductive ability.
Examples: Grasshoppers, cockroaches, dragonflies.

Amphibians undergo complete metamorphosis, where the aquatic larva transforms into a terrestrial adult.
Stages of metamorphosis in frogs:
- Egg: Fertilized eggs develop in water.
- Tadpole: Aquatic larva with gills, a tail, and no legs.
- Developing Frog: Legs grow, tail shortens, lungs develop.
- Adult Frog: Fully developed, capable of living on land.
Metamorphosis in amphibians is controlled by the hormone thyroxine.
Examples: Frogs, toads, salamanders.

Allows insects and amphibians to adapt to different environments during their life cycle.
Reduces competition between young and adults for food and habitat.
Plays a key role in species survival and evolution.

Metamorphosis is a significant biological process in insects and amphibians.
It occurs in two forms: complete metamorphosis and incomplete metamorphosis.
It ensures survival, adaptation, and evolution of different species.