Are Plecos Catfish?

Plecos are considered catfish as they belong to the same family. These fish come from the tropical waters in Northeastern South America and are bottom feeders that scavenge at the bottom of fresh and brackish water bodies.

Although they’re not your typical freshwater tank fish, plecos can be an interesting addition to a large aquarium. They have a unique ability to control algae growth in your tank, so they’re considered an aquarist’s best friend.

Keep reading to learn more about these unique fish and how they relate to catfish.

Albino Bristlenose Pleco

Are Plecos Catfish?

Plecostomus catfish or suckermouth catfish, commonly called plecos, are fish that belong to the Loricariidae catfish family. This is a large family that includes more than 680 species.

Plecos’ bodies are covered in plates and spines that provide protection. In addition, they have suckers around their mouths that allow them to breathe, feed, and attach themselves to rocks and submerged tree branches.

These fish help with algae control when kept in a tank, so they’ll be an excellent addition to your community aquarium.

Plecos are quite hardy, and the armored plates that cover their bodies protect them from predators. They can grow to reach a maximum length of 20 inches and are able to live between 10 and 15 years.

Scientists have discovered about 150 species of plecos, and some of them shouldn’t be kept in aquariums. Others need very special tank requirements to thrive.

Similarities and Differences Between Plecos and Catfish

Catfish belong to a diverse fish family. With too many species, colors, and sizes, you can definitely find the right catfish for your aquarium.

Plecos share some similarities with catfish, but several differences set the two types of fish apart. We’ll discuss them in the following section.


Here are some features that show that plecos and catfish belong to the same family.

They’re Both Nocturnal Fish

Plecos are nocturnal fish that spend their time hiding under tree branches and other structures at the bottom of ponds and rivers. In an aquarium, they’ll hide most of the time in caves and under decorative pieces. They get active at night and start looking for food when most other tank fish are less active.

Most types of catfish are nocturnal too. However, some types are diurnal or crepuscular.

They Don’t Have Scales

Unlike most fish, catfish and plecos’ bodies aren’t covered in scales. However, they don’t look the same.

Most catfish’s bodies have mucus-like skin, which allows the oxygen to pass through. Other types have their bodies covered in bony plates.

These ones are similar to plecos which have bony plates that cover their bodies. The armor-like scutes cover the upper part of the body, while the bottom part shows soft skin.

They Live Near the Bottom

Plecos and catfish are bottom dwellers, usually avoiding the water’s surface and spending most of their time at the bottom of ponds and other water bodies. In a fish tank, Plecos will attach themselves to different surfaces that they can find at the tank’s bottom.

Catfish are also bottom feeders, and their bodies sink instead of float due to their large bony heads and reduced gas bladders.

Albino Pleco Close Up

They’re Peaceful Fish

Most small and medium-sized plecos and catfish species are peaceful and will live in harmony with other fish in a community tank. They’re not aggressive and don’t usually attack other marine creatures in your aquarium.

These fish prefer to hide in underwater caves and behind plants and decorative pieces in the tank, so adding plenty of hiding places is crucial.

However, larger species of catfish can be predatory or aggressive, especially if the tank is overly crowded. They can also attack other fish when they feel stressed or threatened.

Plecos are usually harder to harass than most other species in the aquarium due to their larger size and armored bodies.

They’re Scavengers

Catfish and plecos are scavengers that contribute to the cleanliness of your freshwater tank. These species are omnivores and have a variable diet that consists of plants, fish, algae, and decomposing organic matterl in your tank.

They Have Similar Water Temperature Requirements

Catfish thrive in warm water when the temperature is between 74 and 78 degrees Fahrenheit. In a larger tank, these fish might need a heater or two to maintain this warm temperature.

Plecos also prefer the same warm temperatures. They can tolerate temperatures up to 80 degrees Fahrenheit.


Despite these similarities, there are several differences that set these two fish species apart.

They’re Different in Size

Plecos usually grow to reach a maximum length of 20 inches. There are several catfish species, and some are extremely large, reaching a maximum size of almost 10 feet. On the other hand, there’s a tiny parasitic species that is usually around 7 inches long.

They Live at Different Depths

Plecos usually live at the bottom of shallow water bodies like fast-flowing streams and rivers. However, catfish live at deeper levels, reaching a maximum depth between 15 and 20 feet.

However, in a community tank, both species will live near the bottom.

Plecos Are Less Tolerant

Despite being generally peaceful fish, plecos are usually territorial. They don’t attack other fish in a community tank but don’t get along with other plecos.

On the other hand, catfish are peaceful fish and rarely attack their own kind. Some catfish are also schooling fish.

Plecos Don’t Have Barbels

Catfish have whisker-like barbels. These barbles contain taste buds and help the fish locate food in low-light conditions, as they tend to live near the bottom of murky water bodies. Plecos don’t have these barbels.

Wrap Up

Plecos belong to the same family of catfish. They’re useful scavengers that keep community tanks clean and get along with lots of other fish.

Catfish and plecos have several similarities, and they can both live in the same tank. However, there are some differences that set them apart.

Since there are various types of plecos, you should be careful about the ones you add to your aquarium.