13 Body Parts of a Fish and Their Uses (Common Fish Anatomy)

There are many different types of fish in the world, and each one has its own unique anatomy.

In this blog post, we will take a look at the different parts of a fish and learn about their functions.

Fish come in all shapes and sizes, but they all have some common features. Let’s start by taking a closer look at the body of a fish!

What All Fish Have In Common

With maybe one or two exceptions, fish are vertebrates, which means they have a backbone, just like people.

Fish are aquatic animals which means they live in the water.

Fish are cold-blooded animals, as they cannot maintain their body temperature according to their environment.

For more types of sea creatures, be sure to check out this article.

Fish Anatomy: General Body Areas of The Fish

There are four general areas of the fish.

The back is the dorsal area. The belly is located in the ventral area. The head of the fish is called the anterior area, and the tail can be found at the posterior end.

General Body Areas of Fish

The body of a fish is divided into three main sections: the head, the trunk, and the tail. The head houses the brain and the eyes, the nostrils, and it also contains the mouth. The trunk is the main body of the fish, and it includes the skeleton, the spinal cord, and all of the internal organs. The tail helps to propel the fish through water.

The skeleton of the fish supports the fish, and it is either made of cartilage or bone.

List of Different Parts of A Fish

  • Anal fin
  • Caudal fin
  • Dorsal fins
  • Eye
  • Eyes
  • Gill
  • Gill cover
  • Lateral line
  • Mouth
  • Nostril
  • Pectoral fin
  • Pelvic fin
  • Scales

Fish Body Parts Diagram

Fish Body Parts

Description of Each Part of the Fish

Here is a short description of each body part and how it functions to help the fish survive and thrive in the water.

Anal fin

The anal fin is located on the ventral area (bottom) of the fish, towards the tail. This fin helps to stabilize the fish and provide balance when swimming.

Caudal fin

The caudal fin is also known as the tail fin. This fin helps to propel the fish through water and steer from side to side.

Dorsal fin

Dorsal fins are located on the top of the fish. These fins help to stabilize the fish and control its movement through the water. They stop the fish from rolling on its side by increasing the lateral surface of the body.


Fish have two eyes, which are used to detect movement and prey in their surroundings. They also look for mates, shelter and need to be able to identify danger.

Many species of fish have eyes that are located on either side of the head, and they allow the fish to see in all directions.


The gills are located on either side of the fish’s head. They are used to extract oxygen from water and expel carbon dioxide.

Gill cover

The gill cover (operculum) is a flap of skin that covers the gills. This helps to protect the gills, and it serves a role in respiration.

Lateral line

The lateral line is a series of pores that run along the length of the fish’s body. These pores are used to detect vibrations in the water and sense water movements.


The mouth is located at the front of the fish’s head. It is used for eating and breathing.


The nostrils (also called nares) are located on the top of the head, allowing the fish to smell the water. The nostrils do not play a role in the respiration process.

By smelling the water, fish can detect if another fish is injured and if they need to flee from predators.

Smelling the water can also help them detect chemicals in the water and help them find their way back home. The salmon uses its sense of smell to help it get back to the place it was born!

Pectoral fin

The pectoral fins are located on either side of the fish’s body. These are the equivalent of human arms! 

They are used for steering and moving forward.

Pelvic fin

The pelvic fins are paired and located at the ventral (bottom) of the fish. They are used for stability and help the fish stop moving.


Scales are thin, protective plates that cover the fish’s body. They help to reduce drag in water (the force that opposes movement) and protect the fish from predators.

english courses online

You may also be interested in: 15 Best Online English Courses Free & Paid (2022)

In Conclusion

Fish are fascinating creatures with unique anatomy. By learning about the different parts of a fish, we can better understand their biology and how they live in their aquatic environment. Thanks for reading!

Useful Links

Caitriona Maria is an education writer and founder of TPR Teaching, crafting inspiring pieces that promote the importance of developing new skills. For 7 years, she has been committed to providing students with the best learning opportunities possible, both domestically and abroad. Dedicated to unlocking students' potential, Caitriona has taught English in several countries and continues to explore new cultures through her travels.

Notify of
Inline Feedbacks
View all comments