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
A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.
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
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 Furry Diary 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.21
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.21
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.12
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 Furry Diary 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 Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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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 support@furrydiary.app 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
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.