shark bass

Fish Architecture: Body Shape

Picture a fish in your mind. 

Did it look like this?

or this?

what about this guy?

All of these species highlight the incredible diversity in fish body shape and form. In this post we’ll talk about the 7 most common kinds of fish body shape.

Fusiform:

Most fishes are fusiform in body shape. Characteristics of a fusiform body include being very streamlined and torpedo-shaped. Most fusiform fish often live in open water, and often have tail fins that are deeply forked to enable fast swimming. Some examples of fusiform fish include: tuna, most sharks, striped bass, mackerel (picture 1), and swordfish. 

Compressiform:

Compressiform fish are compressed laterally (from side to side), and include many species of reef fish, moon fish, and flounder. They are able to to swim very quickly in short bursts, and are often found living in and around flora, coral reefs, and other narrow places.

French Angelfish (Pomacanthus paru)

Depressiform:

These fish are compressed dorsoventrally (from top to bottom) and live mostly near the bottom of their environment. They are often predators or scavengers feeding mainly on benthic organisms. To propel themselves, they move their fins in an up and down motion; similar to a bird flapping its wings. Examples of depressiform fish include skates, rays, toadfish, goosefish, and angel sharks.

Spotted Eagle Ray (Aetobatus narinari)

Anguilliform:

From the latin word for eel, anguilliform fish, appropriately are called the eel-like fishes. They have elongated bodies, blunt or wedge shaped heads, and tapering or rounded tails. They will often have long dorsal and anal fins, and sometimes are completely lacking paired fins. Their slender shape allows them to resist current forces as they move through the water. Anguilliform fishes include eels, hagfishes, loaches, and lamprey.

American Eel (Anguilla rostrata)

Filiform:

Similar to anguilliform, filiform fishes are also elongated. However filiform fishes are also very, very thin and sometimes thread-shaped. Snipe eels (picture 2) and pipe fish are some examples of filiform fishes.

Taeniform:

Taeniform fish are ribbon shaped and laterally compressed. this shape is useful for hiding in crevasses, but doesn’t make them particularly fast swimmers. Some taeniform fish include oarfish, gunnels, and cutlassfish.

Giant Oarfish (Regalecus glesne)

Sagittform:

These fish are arrow shaped and look somewhat similar to fusiform fishes. Often, sagittform fishes are lie and wait predators, only able to swim quickly in very short bursts. These fishes include gar, pickerel, pike, and barracuda.

Great Barracuda (Sphyraena barracuda)

Globiform:

Much like their name implies, globiform fishes are very round. They are slow swimmers, and some species have modified their fins to use for walking across the bottom of their environment. Because of their slow speed, many globiform fishes employ defense strategies such as poison, sharp barbs, or sophisticated camouflage in order to prevent themselves from becoming lunch. Globiform fishes include frogfish (picture 2), lumpfish, and pufferfish.