What to Know About the Bristlenose Pleco

Reviewed by Amy Flowers, DVM on December 10, 2022

If you’ve just brought home a plecostomus — or “pleco” for short — you may have questions about the care, feeding, and habitat requirements for your new pet. Learn how to make your bristlenose pleco happy and healthy with the tips listed in the following guide.

The bristlenose pleco, like other algae-eaters, is simply a small catfish with a mouth capable of sucking algae off your fish tank. To identify a bristlenose pleco (or to make sure your pet store labeled the fish you want to purchase correctly), look for the following physical characteristics:

  • A small body (under six inches long): In pet stores, you might find juvenile plecos in groups. These little ones might only be about two inches long. 
  • No scales: All types of catfish in the Loricariidae family have “armor plates” instead of scales. The type of catfish people eat, in contrast, have skin instead of scales or plates.
  • Flat underside with angular fins: Plecos do swim through the water, but they’re also comfortable lying flat on the ground or sticking themselves to the side of your tank with their suction-cup-like mouths.
  • Light gray color: There aren't many bristlenose pleco colors. These small algae-eaters are typically light gray or tan with darker stripes on the tail.
  • Bristles: Every bristlenose pleco has bristles or whiskers near its mouth. Females have smaller bristles, while male plecos have larger ones.

How are bristlenose plecos unique among the 150 species of this common catfish? Consider the points below before you decide to add a bristlenose pleco to your tank.

Their adult size is less than eight inches long. One of the major problems with keeping larger pleco is not understanding its grown-up size. Some plecostomus species rapidly grow as juveniles — and before you know it, you have a two-foot-long fish in your tank.

Larger plecos are great for big tanks (over 50 gallons), but you should understand the responsibility you’re taking on when you buy a pleco. Fortunately, bristlenose plecos do only grow to five to six inches in adulthood and are more appropriate for smaller tanks.

They are bottom swimmers and feeders. Unlike other tropical fish like mollies, tetras, and angelfish that swim to the top of the tank to gobble down flake food, catfish are bottom feeders. This means that when they’re not eating algae from the side of your tank, they will need a special type of food that sinks to the bottom of the tank.

They can live alone or with tankmates. Bristlenose plecos are considered “peaceful” fish (as opposed to semi-aggressive or aggressive types). They will be at home with other peaceful community fish and are compatible with many species you can find in local pet stores. 

It’s not necessary to get a school of plecos to keep in your tank, but you can get more than one if you desire. Keep in mind their adult size — as well as your tank's other inhabitants — to make sure you don’t overstock your tank and contribute to unhealthy water conditions.

Because bristlenose plecos are smaller than other plecostomus fish, you can get away with keeping them in a community tank as an “algae eater” or as an ornamental fish that is capable of living peacefully with many types of tropical fish. 

Do your research before you buy a bristlenose pleco (or any pleco) to determine whether it’s a good match for your tank. Keep the following points in mind:

  • Plecos are nocturnal, and they require you to turn off the tank lights during the night.
  • Plecos are capable of living in nearly any aquarium if they have clean and treated water, food, and a place to hide when they want to get away.
  • Plecos should not be released into streams, ponds, or lakes, as this could damage the local ecosystem. Bristlenose pleco breeding in the wild can get out of control quickly and negatively change the environment. 
  • Plecos should not be put in a tank as “cleaners” if you’re not planning on feeding them additional food and caring for them.

Plecos are known for being algae eaters (and they’re often labeled as such in pet stores). However, assuming that they’ll be able to thrive by only eating the algae that grows in your tank is misleading. As plecos eat both vegetation and tiny crustaceans in the wild, your bristlenose pleco needs a balanced diet of plant matter with small amounts of protein added in.

Because the bristlenose pleco is nocturnal, you should feed it at night time. Consider dropping the food in the tank after you turn the lights off. Your pleco will find the food without a problem — and its tropical tank mates might not be as interested in snagging a bite as they would during the day.

Your bristlenose pleco might live up to 12 years if they’re properly cared for. Keep the following tips in mind when setting up your tank, feeding your fish (including any plecos), and addressing illness in your fish:

  • Let your pleco adjust to the water temperature in your tank before releasing it from the bag. Float the bag on the surface (without letting extra water in) for about half an hour. Don’t pour the bag’s water into your tank to prevent any germs from affecting the fish that are already in your tank.
  • Set up a quarantine tank with the same water parameters for fish that are ill. This will help them not infect their tank mates.
  • Don’t release the pleco into the wild if you can’t care for it any more. If you are unable to find a new home for your pleco, your local fish store should be willing to accept surrendered fish.

Fishkeeping can be difficult at first due to the learning curves involved. If you have questions about your new bristlenose pleco and its care, inquire at your local pet shop or get in touch with an aquatic vet.

Show Sources

American Tarantula & Animals: “5 Things Plecos Like To Eat Most (Diet, Care & Feeding Tips).”
Animal Network: “Pleco.”
Aqua-Fish.net: “Bushynose pleco – Ancistrus temminckii.”
Biodiversity and Conservation: “Invasive aquatic pets: failed policies increase risks of harmful invasions.”
Centers for Disease Control and Prevention: “Fish.”
Discover Animals: “Common Pleco.”
It’s Not Just a Fish: “The Algae Eater Debate."

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