Not furry, but we like them anyway.

Common Pleco

Hypostomus plecostomus (Linnaeus, 1758)

Also called Suckermouth catfish, Algae sucker, Algae eater, Janitor fish, Pez diablo

SpeciesShort profile

From Tropical north-eastern South America: coastal rivers of the Guianas (Oyapock to Essequibo), with Wikipedia also listing north-eastern Brazil and Trinidad and Tobago. It lives in slow, tidal lower river reaches and swamps with muddy bottoms.1 2

At a glance the quick version

Length25 to 50 cm1 2

Lifespan10 to 15 years2

Sizelarge

Very long-lived

Tough armour and hardy nature

Tireless grazer of algae and surfaces

2 1

Looks how to spot one

Armoured suckermouth catfish (bony scutes)

A long, dark catfish whose head and upper body are covered in lengthwise rows of armour-like bony plates. Its mouth sits underneath and works like a suction cup, letting it cling to wood, rocks and glass while it rasps off food.2

Coloursdark overall colouring2

Personality what they are like

A quiet, mostly nocturnal bottom-dweller that rests by day and grazes at night. It is generally left alone by other fish thanks to its armour, though adults can be a little pushy with other bottom-dwellers.2

Daily activity how busy a day looks

Most active after dark; it needs a long tank with caves or driftwood for daytime resting.2 1

Grooming and care the hands-on bits

It produces a lot of waste for its size, so strong filtration and regular water changes are important. It grows big, so plan for an adult-sized tank from the start, and never release one into the wild.2

Home where they are happiest

Tropical water around 20 to 28 C (FishBase) or 22 to 30 C (Wikipedia), pH about 6.2 to 8.2, tolerant of soft to quite hard water. Provide driftwood and caves; a very large tank is needed for an adult.1 2

Food basics what goes in the bowl

An omnivore that grazes algae and also eats plant matter and small crustaceans. In aquariums, algae wafers, blanched vegetables and some protein foods keep it well fed.2 1

Company who they like around

Usually kept as a single specimen; it is solitary by nature and can be territorial toward other plecos.2

The story where it all began

Carl Linnaeus named this fish in 1758, making it one of the first catfish ever scientifically described. Its genus name comes from Greek words meaning 'under' and 'mouth', a nod to its suckermouth.2 1

Fun facts for the dinner table

1
It can breathe air when needed, a useful skill in the swamps and tidal rivers where it lives.1
2
Parents lay eggs on smooth rocks, and one or both adults guard them.1
3
It has a long list of nicknames around the world, including 'janitor fish', 'devil fish' and, in Malaysia, 'municipal fish'.2
4
It is farmed for the aquarium trade in Singapore and Hong Kong.1

Recognised by the official bits

IUCN Red List: Least Concern (assessed 14 February 2021)1
Taxonomy: Described by Linnaeus in 1758; family Loricariidae1
Aquarium trade: Many fish sold as 'common pleco' are actually Pterygoplichthys species2

The care rhythm a typical week and year

A typical home-care rhythm for a Common Pleco. A starting point, not a vet's advice.

Feedingevery day
Water changeAbout 30 to 50% of the waterevery week
Water testevery week
Filter rinseevery 2 weeks

Owner questions the things everyone asks

How often should I feed my Common Pleco?

Feed once a day, ideally in the evening when it is most active. Furry Diary's starting plan is to feed daily, and you can adjust based on how much it eats.2 Pet Wiki plan

What does a Common Pleco eat, and what should it never eat?

It is an omnivore that grazes algae, so offer algae wafers, blanched vegetables, and some protein foods. Never feed it anything not meant for fish, and avoid overfeeding as it produces a lot of waste.2 1

How much space does a Common Pleco need?

It grows big, so plan for a very large tank from the start to fit an adult. A long tank with caves or driftwood is ideal for its daytime resting.2 1

What temperature, light or water does a Common Pleco need?

Keep tropical water around 20 to 30 C, with pH about 6.2 to 8.2, and it tolerates soft to quite hard water. Provide driftwood and caves, and keep lighting moderate since it rests by day.1 2

How often should I clean a Common Pleco's home?

Clean weekly with a water change of about 30 to 50%, and rinse the filter every two weeks, per Furry Diary's plan. It produces a lot of waste, so strong filtration and regular changes are key.2 Pet Wiki plan

Can a Common Pleco live with others?

It is usually kept as a single specimen, as it is solitary and can be territorial toward other plecos. It generally leaves other fish alone thanks to its armour, but adults may be pushy with bottom-dwellers.2

How long does a Common Pleco live?

It typically lives 10 to 15 years, so be ready for a long-term commitment. Its lifespan depends on good care, including a proper tank and diet.2

Can I handle a Common Pleco?

Handling is not recommended, as it is a delicate fish with a suction-cup mouth and armour. It is best to leave it in the water and use a net only when necessary, and ask a vet or good breeder for advice.2

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

Sailfin Pleco

Leopard Sailfin Pleco

Bristlenose Pleco

Where this comes from

Every fact on this page has a numbered source. Spotted an error? [email protected].

FishBase: Hypostomus plecostomus fishbase.seused for distribution, habitat, size, water parameters, IUCN, breeding, air breathing
Wikipedia: Hypostomus plecostomus en.wikipedia.orgused for names, size, lifespan, appearance, behaviour, diet, etymology, trade confusion

Checked 2026-09-30. Text is written in our own words from these sources.