5 Difference between Molting and Metamorphosis (with Table)

Molting and metamorphosis are events of the life cycle of animals. In both, the structures of the body change.

Molting refers to the shed of outer body covering, feathers, hair, or skin to make a way for new growth. Metamorphosis is the process of transformation where the immature creature is transformed into a mature creature through a series of stages.

The two are controlled by two classes of hormones; ecdysteroids and juvenile. Juvenile hormone triggers molting and suppress metamorphosis.

Many have been confused between the two. Some animals are transformed through molting while others are transformed through metamorphosis.

So, what is the main difference between molting and metamorphosis? Molting is the shedding of body parts periodically while metamorphosis refers to the process of transformation from an immature form through distinct stages.

This article is going to give you clear differences between molting and metamorphosis. You will also get to learn about the similarities between the two.

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Comparison Table (Molting vs Metamorphosis)

Basic Terms Molting Metamorphosis
Meaning It is the shedding of the outer covering to give way to new growth. It is the process of transformation from immature to mature form through distinct life stages.
Where it occurs It occurs in arthropods, amphibians, birds, and reptiles. It occurs in cnidarians, insects, crustaceans, mollusks, and animals such as fish, amphibians, and all chordates.
Types Shed of the exoskeleton in insects. They are of two types; complete and incomplete metamorphosis.
Role Helps animals to improve in size of the body. Helps to transform from one life stage to another.
Stages It does not involve stages. It transforms through stages.

What is Molting?

Molting is the process where animals shed off their exoskeleton to give way for new growth. It enhances growth in animals.

The exoskeleton that covers insects prevents water loss from its body and protects the internal organs but it inhibits it’s the growth of the animal.

For the animal to the growth of the animal, the exoskeleton needs to be shed off hence molting is a process that initiates growth in insects.

The process where the exoskeleton is shed is referred to as ecdysis. It is also involved in the shedding of the epidermis and pelage. It helps different animals to adapt to various environmental changes.

What is Metamorphosis?

Metamorphosis refers to the transformation from immature to adult form through distinct stages. There are two types of metamorphosis; complete and incomplete metamorphosis.

Complete metamorphosis includes four stages; egg, larva, pupa, and adult of which the stages differ greatly morphologically.

It starts with female insects laying eggs, and when they hatch to the larval stage which is typically different from the adult stage morphologically.  The larval body is soft and warm-like.

The larval stage shows very fast growth as it has a high appetite for food. It molts its skin several times during its growth.

The third stage is the pupa, which is an inactive stage as it begins with the formation of cocoons around the larvae. Their bodies develop more segments, internal organs, wings, and legs. A fully grown adult is finally freed from the cocoon.

Incomplete metamorphosis includes three stages. It does not have a larval stage. Gradual changes occur in the insect from the egg up to the adult.

Egg, nymph, and adult are the three stages of incomplete metamorphosis. The nymph normally looks like an adult without wings.

Nymph is smaller than adults although it eats the same food as the adult. It develops into adults through a series of molts.

Main Difference between Molting and Metamorphosis

  1. Molting is where animals shed off their exoskeleton to allow new growth while metamorphosis is the transformation of immature to adult form through a series of stages.
  2. Molting occurs in one type while metamorphosis occurs in two types; complete and incomplete metamorphosis.
  3. Molting helps to increase the size of the insect while metamorphosis helps to transform from immature stage to adult stage.
  4. Molting does not involve stages while metamorphosis involves stages.

Similarities between Molting and Metamorphosis

  1. They both bring the nymph to adult.
  2. Both are structural changes of the body
  3. Both are types of events in an animals’ lifecycle.


Molting and metamorphosis make the animals change structurally. The two types of life events in animals enable them to be adults.

Molting and metamorphosis are different in that molting involve the shedding of the exoskeleton to give rise to new life while metamorphosis is a transformation process that involves immature form being transformed to mature form through distinct life stages.

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