Bristlenose plecos with shrimp

By the Shrimp Tank Hub editorsUpdated Oct 26, 2026Research-based

The bristlenose pleco, or bristlenose catfish (Ancistrus), is the small armored suckermouth catfish sold in almost every store as an algae eater. The common aquarium form is bred commercially, its exact species is unknown, and it may be a hybrid (Seriously Fish, Practical Fishkeeping, The Shrimp Farm). Adult males grow the fleshy "bristles" on the head that give it its name (Seriously Fish). Unlike the true common pleco, which Aquarium Co-Op says can grow to nearly 2 feet, the bristlenose usually stays around 4 to 5 inches.

Bristlenose plecos at a glance

Will a bristlenose eat shrimp?

• Adults: no. The Shrimp Farm's tankmates guide rates the bristlenose "does not eat adult shrimp" and calls it an ideal community fish.
• Shrimplets: mostly safe, but no promises. Practical Fishkeeping says many aquarists keep bristlenoses with shrimp colonies, with some baby shrimp surviving in well-established, densely planted tanks. Aquarium Co-Op says plecos are scavengers that generally don't eat other animals unless they have already died, and adds that some bristlenose breeders put cherry shrimp in their breeding tanks to clean up leftover food, because the shrimp don't prey on the eggs or fry.
• Dead shrimp: a bristlenose will scavenge a shrimp that has already died. That is clean-up, not hunting; if you find shrimp dying, see why are my shrimp dying.

Our reading: among bottom-dwelling fish, the bristlenose is one of the gentler choices for shrimp. Its downside is not predation but size, waste and appetite. Compare otocinclus with shrimp, a much smaller algae-grazing catfish, and the full list in cherry shrimp tank mates.

For a smaller, group-living bottom dweller that eats sinking food rather than algae, see corydoras with shrimp.

The real issue: competition for algae and biofilm

Practical Fishkeeping says bristlenoses mainly graze algae, aufwuchs and biofilm, and rasp at surfaces such as driftwood. That is the same film shrimp spend their day picking at; see algae in a shrimp tank. A hungry 5-inch pleco can clean a small tank's surfaces faster than shrimp can, and Practical Fishkeeping warns that relying on naturally occurring algae can leave a bristlenose underfed, especially in a clean or new tank. Aquarium Co-Op says plecos are not algae-only fish and need proper meals, and that a common failure is a single algae wafer a night.

• Feed the pleco on purpose: fresh vegetables such as cucumber and courgette (zucchini), algae-based wafers and sinking herbivore foods, with only small amounts of protein (Practical Fishkeeping). Shrimp will share blanched vegetables too.
• Feed after lights out: Aquarium Co-Op suggests feeding nocturnal plecos when the lights are off, which also leaves daytime biofilm for the shrimp.
• Check the belly: Aquarium Co-Op suggests aiming for a slightly rounded belly and adjusting portions from there.
• Remove leftovers: uneaten vegetables foul shrimp water. See best shrimp food and how long shrimp can go without food.

Matching the water

The shared zone is our comparison of the published ranges, not a tested target. Practical Fishkeeping says stability matters more than chasing exact numbers and that bristlenoses are tropical fish that need a heater. Seriously Fish and Practical Fishkeeping both say they prefer well-oxygenated water with some flow and surface agitation. See shrimp tank temperature, shrimp tank pH and nano shrimp tank heaters.

Tank size and setup

• Size: Seriously Fish and Practical Fishkeeping give a 24 × 12 in footprint as the minimum for one fish or a breeding pair, with more needed for a group. Aquarium Co-Op says 20 to 29 gallons or more, and The Shrimp Farm lists 30 gallons and up. A bristlenose is not a nano-tank fish; skip it in tanks under about 20 gallons. Practical Fishkeeping says footprint matters more than height.
• Caves and wood: Practical Fishkeeping recommends wood and rocks arranged into shaded overhangs or caves, with more caves than catfish. Driftwood also grows biofilm both animals graze; see driftwood and botanicals for shrimp.
• Plants: Practical Fishkeeping says bristlenoses can uproot delicate or newly added plants and may rasp holes in broad leaves such as Amazon swords, and Aquarium Co-Op also notes they sometimes snack on swords. Let plants and moss establish before adding the pleco; see java moss and best plants for a shrimp tank.
• Filtration and flow: pick a filter with good surface agitation, and use a sponge or pre-filter on the intake so shrimplets aren't pulled in; see shrimp-safe filters.

Waste and water quality

A 5-inch fish adds far more waste than a school of nano fish. Aquarium Co-Op advises regular maintenance to keep nitrate at 40 ppm or below for plecos, and says lots of long, stringy pleco waste is a sign to vacuum and change water. Shrimp keepers usually aim lower than that; see nitrate in a shrimp tank and shrimp tank water changes.

One pleco or several?

For most shrimp tanks, one bristlenose is enough. Seriously Fish and Practical Fishkeeping say males are territorial with each other and with similar cave-dwelling fish, and Aquarium Co-Op says multiples work only with more females than males and plenty of caves. A male and female will breed readily (Practical Fishkeeping, Aquarium Co-Op), and Practical Fishkeeping suggests thinking about what you will do with the offspring before you start. Every extra pleco is more competition for the shrimp's food.

Not a common pleco

Aquarium Co-Op says the common pleco (Hypostomus plecostomus) is often sold small as a cleaner fish but grows to nearly 2 feet, needs a very large tank, and must never be released into the wild because it is invasive. Make sure you are buying a bristlenose (Ancistrus); adult males show the head bristles (Seriously Fish). Albino, piebald and long-finned forms are bristlenoses too (Seriously Fish).

How to add a bristlenose to a shrimp tank

• Shrimp first. Practical Fishkeeping suggests letting the colony build up before adding fish.
• Mature tank: a pleco needs established algae and biofilm plus extra food; see how to cycle a shrimp tank.
• Quarantine the fish separately. Practical Fishkeeping says many fish medications are not safe for invertebrates. If fish get sick, ask a fish veterinarian or an experienced store about treatment that won't harm the shrimp. See how to quarantine and is copper toxic to shrimp.

Common mistakes

• Buying a "pleco" that turns out to be a common pleco.
• Putting a bristlenose in a 10-gallon or smaller shrimp tank.
• Expecting it to live on algae alone, or starving the shrimp of biofilm.
• No caves or wood.
• Adding it before plants are rooted.
• Letting nitrate creep up from pleco waste and leftover vegetables.
• Medicating fish in the shrimp tank.

Track it

Log temperature, pH, GH and TDS on the free Water Parameter Log printable so you can keep the tank in the range both species share.

Frequently asked questions

Do bristlenose plecos eat shrimp?

Not live adult shrimp. The Shrimp Farm rates the bristlenose as not eating adult shrimp, and Aquarium Co-Op says plecos are scavengers that do not eat other animals unless they have already died.

Will a bristlenose eat baby shrimp?

It is not considered a shrimplet hunter. Practical Fishkeeping says many aquarists keep bristlenoses with shrimp colonies, with some baby shrimp surviving in established, densely planted tanks.

What size tank does a bristlenose pleco need with shrimp?

References vary: a 24 by 12 inch footprint for one fish or a pair (Seriously Fish, Practical Fishkeeping), 20 to 29 gallons or more (Aquarium Co-Op), or 30 gallons and up (The Shrimp Farm). It is not a nano-tank fish.

Will a bristlenose steal food from my shrimp?

It competes for algae and biofilm. Practical Fishkeeping says algae alone is not enough for a bristlenose, so feed vegetables and algae wafers, ideally after lights out as Aquarium Co-Op suggests.

Is a bristlenose the same as a common pleco?

No. Aquarium Co-Op says the common pleco can grow to nearly 2 feet, while bristlenoses stay around 4 to 6 inches.

What water do bristlenose plecos and cherry shrimp share?

By our comparison of the published ranges, about 72 to 79 °F, pH 6.5 to 7.5 and GH 4 to 8.

Sources: The Shrimp Farm, Shrimp tankmates and compatibility (bristlenose pleco: Ancistrus cf. cirrhosus, up to 5 in, 30+ gallons, beginner-proof, does not eat adult shrimp; bushymouth catfish, likely a hybrid, friendly, sturdy, ideal community fish); Seriously Fish, Ancistrus sp. '3' (common bristlenose) (common bristlenose Ancistrus sp. '3', commercially bred, unknown origin, possibly a hybrid; 125 mm SL; 60 × 30 cm base for one fish or a breeding pair, larger for a group; prefers well-oxygenated water; plenty of cover; 21–26 °C, pH 5.5–7.5, 1–15 dGH; varied diet with sinking foods and vegetables; territorial with conspecifics and similarly shaped species; males have head tentacles; cave spawner, male guards; juveniles may appear in mature tanks; piebald, albino, xanthic and long-finned forms); Practical Fishkeeping, Bristlenose catfish: the hardworking Ancistrus (common plecos over 50 cm; bristlenoses typically about 12 cm, 15 cm cited maximum, usually 10–12 cm; captive-bred, possibly hybrids; 60 × 30 × 30 cm for one fish or a pair, larger for a group, footprint over volume; wood, rocks, caves, more caves than catfish; can uproot delicate or new plants and rasp Amazon swords; pH 6–7.5, up to 8 usually acceptable, under 18 °dH; 22–26 °C, needs a heater; likes flow and surface agitation; peaceful, territorial with conspecifics over caves; many aquarists keep them with shrimp colonies, some baby shrimp surviving in well-established, densely planted tanks; graze algae, aufwuchs and biofilm; algae alone can leave them underfed; cucumber, courgette, algae wafers, sinking herbivore foods, little protein; breed readily, plan for offspring); Aquarium Co-Op, Care guide for plecostomus (common pleco Hypostomus plecostomus nearly 2 ft, large waste load, invasive, do not release; bristlenose 4–6 in, 20–29 gallons or more; 74–80 °F, pH 6.5–7.8; nitrate 40 ppm or below; mostly nocturnal, provide hides, feed with lights off; need real meals, not only algae wafers; slightly rotund belly; long stringy waste means vacuum and change water; scavengers that won't eat other animals unless already dead; bristlenoses sometimes snack on sword plants; multiples with more females and plenty of caves; breeders add pest snails or cherry shrimp to bristlenose breeding tanks since they don't prey on eggs or fry); Practical Fishkeeping, What can I keep with shrimp? (let the colony build first; plants and hiding places; many fish medications unsafe for invertebrates); The Shrimp Farm, Red rili shrimp tank set-up and care (cherry-type Neocaridina: 65–85 °F, pH 6.2–8.0, GH 4–8). The shared water zone is our own comparison of these ranges.