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
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.12
At a glance the quick version
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
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.21
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.12
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.21
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.21
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 Furry Diary remembers it for you
A typical home-care rhythm for a Common Pleco. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- Feedingevery day
- Water changeAbout 30 to 50% of the waterevery week
- Water testevery week
- Filter rinseevery 2 weeks
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- 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.