Pleco - Plecostomus

Suckermouth Catfish, Armor-Plated Catfish

Pleco, Plecostomus, Hypostomus Plecostomus, Suckermouth CatfishHypostomus plecostomusPhoto © Animal-World: Courtesy Joe Wirkus
Latest Reader Comment - See More
Is it normal for a pleco to stay on its back for 5 - 6 hrs? I thought it was dying, then all of a sudden it went nuts (swimming, jumping, diving).. now it follows... (more)  barb tuck

The Plecostomus is a very hardy fish that loves to eat algae, especially when young!

The Pleco or Plecostomus Hypostomus plecostomus is a fish that just about everyone is familiar with. Most freshwater aquarists have added them to a tank at one time or another. This is the catfish most commonly used for getting rid of problem algae in the aquarium. It is one of the hardiest and most enduring of all catfishes.

The Pleco is an unusual fish in body shape with its underslung suckermouth, tall dorsal fin and moon-shaped tail fin. It can also roll its eyes in there sockets, making it look like its winking. Its normal coloring is a light brown that is heavily patterned with dark blotches of stripes and spots, making it look like a very dark fish. There are also varieties of this species that are missing some or all of the dark patterning, so this fish is also available as an Albino Pleco.

The Common Pleco is typically purchased as a juvenile when it is about 3 inches (8 cm) in length, but this fish gets very large as an adult. It can reach about 24" (61 cm) in length, though they seldom exceed 12 - 15" (30.5 - 38 cm) in the aquarium. They are fast growing, and have an average lifespan of 10 - 15 years in captivity.

Juvenile Plecostomus are easy to care for. They are nocturnal, getting active and feeding at night. Some driftwood or other decor should be provided to give them caves to hide in during the daylight hours. They are also jumpers, so be sure to have a cover on the aquarium. Although Plecs are omnivorous, they primarily feed on algae in the aquarium.

This is a very friendly, good natured fish when young. Juvenile plecos will generally get along with most other tankmates, even Cichlids and other aggressive fish. One exception to this is they can get aggressive and territorial towards other plecos if they were not raised together. They will also defend their favorite spot from other types of fish with similar habitat requirements, like Rope Fish, some eels, and some knifefish.

There are a few words of caution when keeping these fish. They have been known to remove slime from laterally flattened fish like discus and angelfish when they are sleeping, and also goldfish. Even though they are herbivores they can get quite large and can become too big for small aquariums. As they mature they may also become more aggressive and are then best kept singly in a large tank.

For Information on keeping freshwater fish, see:
Freshwater Aquarium Guide: Aquarium Setup and Care


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Pleco - Quick Aquarium Care
  • Temperament: Peaceful
  • Aquarium Hardiness: Very Hardy
  • Aquarist Experience Level: Beginner
  • Diet Type: Omnivore
  • Minimum Tank Size: 55 gal (208 L)
  • Temperature: 66.0 to 79.0° F (18.9 to 26.1° C)
  • Range ph: 6.5-8.0
  • Hardness Range: 1 - 25 dGH
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Habitat: Distribution / Background

Pleco or Plecostomus Hypostomus plecostomus was described by Linnaeus in 1758. They are found in northern South America. They inhabit ponds and the fresh and brackish waters of river mouths on both the Pacific and Atlantic Ocean slopes. The term plecostomus means "folded mouth" and is applied to a large number of species with a suckermouth characteristic, though they differ in length, coloration, and other features like the whisker type extensions around the mouth of the Bristle-nose Catfish Ancistrus spp. Common names this fish is know by include Pleco, Plecostomus, Plec, Suckermouth Catfish, Armor-Plated Catfish, Algae Eater, and Suckerfish.

There are many species of Suckermouth Catfish sold under the name "Pleco". There are over 120 Hypostomus species alone, and at least 50 of them have a spotted patterning. Some that are very similar to this species, and also commonly available, include the Trinidad Pleco or Spotted Pleco Hypostomus punctatus , Orinoco Sailfin Catfish Pterygoplichthys multiradiatus , Amazon Sailfin Catfish Pterygoplichthys pardalis , and the Leopard Pleco or Clown Plecostomus     Glyptoperichthys gibbiceps . Lots more species are occasionally available, including many that science has yet even described.

  • Scientific Name: Hypostomus plecostomus
  • Social Grouping: Pairs - In the aquarium they are incompatible with their same species unless they have been raised together. As adults they can become territorial and aggressive.
  • IUCN Red List: NE - Not Evaluated or not listed

Description

The Pleco has an elongated body covered by bony plates everywhere except the belly. It has a, tall sailfin type dorsal fin and a large head that grows larger with age. The mouth is underslung with suction-cup like lips that adhere to smooth surfaces to suck algae. Its eyes are small, set high on the head, and give a winking appearance as they roll inside the sockets.

Its normal coloring is a light brown base heavily covered with dark blotches patterned in stripes and spots, making it look like a very dark fish. There are also varieties of this species that are missing some or all of the dark patterning, so this fish is also available as an Albino Pleco.

These fish get up to 24 inches (60 cm) though they seldom exceed 12 - 15" (30.5 - 38 cm) in the aquarium. They are fast growing, and have an average lifespan of 10 - 15 years in captivity. In the wild they can live more than 15 years.

  • Size of fish - inches: 24.0 inches (60.96 cm) - These fish seldom exceed 12 - 15" (30.5 - 38 cm) in the aquarium.
  • Lifespan: 15 years - In the wild they can live more than 15 years, but have an average lifespan of 10 - 15 years in captivity.

Fish Keeping Difficulty

The Plecostomus is easy to care for as long as there is plenty of algae and/or other algae based foods provided, making it a great fish for the beginner. The chemistry is not critical, but its quality must be good. Be aware that the Plecostomus grows quickly and becomes quite large, so will require a large tank with age.

  • Aquarium Hardiness: Very Hardy
  • Aquarist Experience Level: Beginner

Foods and Feeding

Although Plecostomus are omnivorous, the bulk of their diet is algae. They will eat undesirable algae and will generally not harm plants. Provide an aquarium that is well established with lots of natural algae growth. Also feed supplements including algae wafers, green foods and sinking pellets to make sure they don't starve. Some supplement that can be offered include vegetables like blanched spinach, lettuce, and peas as well as live worms, small crustaceans, and insect larvae. These fish may graze on the plants if they are not feed sufficient amounts. It is best to feed them in the evening just before turning out the lights. Note: they have not been observed to eat blue algae.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet - Occasional supplements of live worms, small crustaceans, and insect larvae can be offered
  • Vegetable Food: All of Diet - Although they are omnivorous, the bulk of their diet is algae. Supplement that can be offered include vegetables like blanched spinach, lettuce, and peas, as well as fruit.
  • Meaty Food: Some of Diet
  • Feeding Frequency: Daily

Aquarium Care

The chemistry is not critical, but its quality must be good. Good filtration and regular water changes are important because of the large amount of waste this catfish produces. The recommended water change is 15% once a month, change it more often if the water is heavily fouled.

  • Water Changes: Monthly - The recommended water change is 15% once a month, change it more often if the water is heavily fouled.

Aquarium Setup

A minimum 55 gallon aquarium is recommended for the Pleco. Although when small they can be kept in a smaller aquarium for a short period of time, these are fast growing fish and will soon need to be moved. Some driftwood or other decor should be provided to give them caves to hide in during the daylight hours. They also like a well planted tank, but use hardy species as they can damage delicate plants as they move around grazing on algae growths. They are also jumpers, so be sure to have a cover on the aquarium.

Keeping some wood in the tank offers a number of benefits besides offering a place of refuge. Their rasping action to remove algae from the wood provides a perfect place for more algae to grow maintaining a constant food source for this fish. Also, the cellulose in wood is necessary for their digestive process.

  • Minimum Tank Size: 55 gal (208 L) - Juveniles may be kept in a smaller aquarium for a short period of time, but these fish are fast growing and will need a larger tank as adult.
  • Suitable for Nano Tank: Sometimes
  • Substrate Type: Any
  • Lighting Needs: Moderate - normal lighting
  • Temperature: 66.0 to 79.0° F (18.9 to 26.1° C)
  • Range ph: 6.5-8.0
  • Hardness Range: 1 - 25 dGH
  • Brackish: Sometimes - In the wild they live both fresh and brackish water, as some are ound in the mouths of rivers flowing into the ocean. But in captivity they do fine in a freshwater aquarium.
  • Water Movement: Moderate
  • Water Region: Bottom - The Pleco or Plecostomus will swim in the bottom of the aquarium.

Social Behaviors

They are a good community fish when young, and can be kept with almost all other fish. But it does not get along with its own species and can become aggressively territorial as it becomes older. They have been known to remove slime from laterally flattened fish like discus and angelfish when they are sleeping, and also goldfish.

  • Venomous: No
  • Temperament: Peaceful
  • Compatible with:
    • Same species - conspecifics: Sometimes
    • Peaceful fish (): Safe
    • Semi-Aggressive (): Safe
    • Aggressive (): Safe
    • Large Semi-Aggressive (): Safe
    • Large Aggressive, Predatory (): Safe
    • Slow Swimmers & Eaters (): Safe
    • Shrimps, Crabs, Snails: May be aggressive - Although they primarily eat algae, they may snack on small crustaceans if they aren't fed an adequate amount of food.
    • Plants: Safe - They prefer a planted aquarium, but use hardy specimens.

Sex: Sexual differences

Plecoscostomus fish are difficult to sex for all but the most experienced. A trained eye can compare a male and female, with a male's genital papilla being a small but thick stub protruding from its undercarriage. On the female it will be either recessed or lie flat on the body.

Breeding / Reproduction

In the wild, the Plecostomus breeds in deep burrows excavated in riverbanks. Reproduction in the aquarium is unsuccessful, but this fish is bred in large quantities in Singapore, Hong Kong, and Florida. They are bred in large commercial fishery ponds where a spawning pit is fanned out in the side of the muddy steep banks. A pair will spawn about 300 eggs and the male will guard the eggs, and then the fry. The fry feed off of mucus excreted from the body of the parents. At the end of this breeding period, the ponds are then drained, and the young and parents are removed.

  • Ease of Breeding: Difficult - These fish will not propagate in the aquarium, but have been reproduced in large commercial fishery ponds.

Fish Diseases

Plecos are very hardy fish, but are subject to the same diseases as other tropical fish. One of the most common freshwater fish ailments is ich. For information about freshwater fish diseases and illnesses, see: Aquarium Fish Diseases and Treatments.

Because they are a scaleless fish, catfish can be treated with pimafix or melafix but should not be treated with potassium permanganate or copper based medications. Malachite green or formalin can be used at one half to one fourth the recommended dosage. All medications should be used with caution.

Availability

The Pleco or Plecostomus Hypostomus plecostomus is readily available from pet stores and online, and is moderately priced.

References

Author: Clarice Brough CFS
Lastest Animal Stories on Pleco

barb tuck - 2014-04-05
Is it normal for a pleco to stay on its back for 5 - 6 hrs? I thought it was dying, then all of a sudden it went nuts (swimming, jumping, diving).. now it follows me when I pass the tank..

  • Jasmine Brough Hinesley - 2014-04-12
    That doesn't sound exactly typical, but it sounds like he is doing fine now. Just keep an eye on him to make sure you don't see any other signs of illness. Also do the recommended water changes (about a fifth of the tank once a month) and check the water quality and temperature.
Reply
Monique - 2014-02-07
I got a Pleco for our established aquarium with plenty of algae, it lived for one week. Mt temps are correct and my other fish are fine...was wondering what we did wrong before i get another one...any info would help. Thank You

  • Clarice Brough - 2014-02-08
    Pleco's are generally very hardy, a week suggests it may have had issues when you bought it. Talk to your supplier, they may replace it for you.
Reply
Kate H - 2012-10-02
I've noticed my little suckerfish going up for air several times. I'd not seen him do this previously. Am I worrying with reason or is this normal behavior?

  • Jeremy Roche - 2012-10-02
    They do this at times to help maintain bouyancy.  Also will do it when water conditions may need to be tested.
Reply
Anonymous - 2012-02-02
Hi, um, my senegal bichir is in love with my pleco and I am very confused. P.S. my senegal bichir even brings the pleco its food if it isn't close enough to the hiding place!

  • Charlie Roche - 2012-02-02
    AHH doesn't make much difference if you are confused - they don't seeem to be. No one tells an animal/fish/bird how to behave and they frequently behave outside what we think is the normal for the little fella. My daughters dog (big one) sleeps with the dwarf rabbit. My Queen (conure) is in love with my macaw. They're happy - why worry.
Reply
sonia - 2012-03-18
About the breeding. This happened completely by accident. I have a albino bristlenose longfined pleco and an albino pleco and they just had babies. There are about 18 of them and they are about the size of half a pea. They are pinkish orange and I can already see the fins. I find this to be quite the experience since they are in a 35 gallon tank with a variety of chilids.

Reply

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