Difference between Internal and External Fertilization

Internal fertilization takes place within the female reproductive system such in Mammals, reptiles, some birds, and some fish while external fertilisation is the fertilization process in which a male and a female gamete fuse outside of the female’s body such in Frogs, fish, molluscs, and crustaceans all engage in.

Here are some of the main differences between them to help you understand how both differ:

Internal Fertilization Vs External Fertilization:

Internal Fertilization:

The internal fertilization, whereby the female body’s gametes combine with the male gametes to produce offspring.

There are more animals, including humans, cows, dogs, and hens, whose progeny have a higher probability of surviving internal fertilization.

External Fertilization:

When a male and a female gamete unite outside of the female’s body during fertilization, the process is known as external fertilization.

Less likely that the children will survive.

Aquatic animals like fish, starfish and other species frequently exhibit it.

What is Difference between Internal and External Fertilization?

In internal fertilization a female organism gets involved in sexual reproduction, the gametes are fused internally (internal fertilization), while externally (external fertilization), which occurs when the female organism engages in sexual reproduction.

 Let’s discuss the difference between them as follows:

Internal Fertilisation:

Internal fertilization takes place when gametes fuse during sexual reproduction in female organisms.

The female organism undergoes internal fertilization.

The three types of internal fertilization are oviparity, viviparity, and Ovo vivipary.

Mammals, reptiles, some birds, and some fish can fertilize internally.

Bryophytes, pteridophytes, gymnosperms, and angiosperms all undergo internal fertilization.

High embryo survival rates are seen in internal fertilization.

During internal fertilization, fewer gametes are generated than external.

In internal fertilization, a chosen person receives the male gametes.

Examples include fish, amphibians, most types of algae, etc.

External Fertilization:

When a female creature reproduces sexually, external fertilization is when gametes fuse outside of the female organism.

Fertilization takes place external to the female organism.

The external environment is where external fertilization takes place.

Fish, molluscs, crabs, frogs, and other organisms all use external fertilization.

Unlike internal, Most algae rely on external fertilization.

Lower embryo and egg survival rates are seen with external fertilization

During external fertilization, a huge number of gametes are created.

A lot of genetic variation is produced through external fertilization.

Examples include mammals, bryophytes, birds, reptiles, and avian life.


After reading this article you learned a lot about the differences between internal and external fertilization, they are no longer able to confuse you.

Internal and exterior fertilization are the two methods of fertilizing gametes during sexual reproduction in both animals and plants. Higher animals and plants both experience internal

fertilization whereas, lower animals and plants experience external fertilization.

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