Pygmy corydoras with shrimp

By the Shrimp Tank Hub editorsUpdated Oct 25, 2026Research-based

The pygmy cory (Corydoras pygmaeus, now often listed as Gastrodermus pygmaeus) is one of the smallest catfish in the hobby, at about 2.5 to 3 cm (1 to 1.2 in). Unlike most corydoras, it spends much of its time hovering in midwater, often in loose schools (Seriously Fish, Aquarium Co-Op). It is peaceful enough that Seriously Fish suggests keeping it with other tiny species, including small freshwater shrimp, and Aquarium Co-Op says it won't bother adult dwarf shrimp.

Pygmy cory at a glance

Two similar dwarf corys are often confused with it. Aquarium Co-Op's quick ID: the pygmy has a thin black stripe along the body, C. hastatus has a big black spot at the base of the tail, and C. habrosus has an uneven stripe with darker blotches. All three are small enough for a shrimp tank.

Will pygmy corydoras eat shrimp?

• Adults: no. Aquarium Co-Op says pygmy corys won't bother snails or adult dwarf shrimp.
• Shrimplets: occasionally. Aquarium Co-Op notes they may accidentally slurp up a baby shrimp while foraging, and Practical Fishkeeping counts corys among fish whose losses you can reduce with plenty of plants, hiding places and well-fed fish.
• Behavior: Practical Fishkeeping says shrimp may hide more and breed less with any fish present, and that fish usually beat shrimp to food.

Because pygmy corys spend so much time in midwater and have tiny mouths, the trade-off is usually small. Moss and dense plants give shrimplets cover, and a cherry shrimp colony normally keeps growing. For rare shrimp or if you sell shrimp, Practical Fishkeeping's advice is that a shrimp-only tank is safest. See cherry shrimp tank mates for other options.

Matching the water

Pygmy corys come from soft, slightly acidic to neutral water, while cherry shrimp and other Neocaridina are usually kept neutral to slightly hard. The ranges overlap well:

The shared zone is our comparison of the published ranges, not a tested target. Seriously Fish says this species needs a steady pH and temperature, so stability matters more than hitting an exact number. Soft-water Caridina such as crystal red shrimp are often kept below pH 7 on active soil, which is close to the low end of the pygmy cory's range. See shrimp water parameters, shrimp tank pH and shrimp tank temperature.

Tank size and setup

• Size: Seriously Fish says a fairly large group fits in a tank of 45 × 30 × 30 cm (about 11 gallons). Aquarium Co-Op says a small group could technically fit in 5 gallons but recommends 10 gallons or more so you can keep a bigger, bolder school. See how many shrimp per gallon.
• Plants and cover: both sources suggest plenty of plants and hardscape. Aquarium Co-Op often finds pygmies perched on anubias leaves and driftwood, and Seriously Fish suggests floating plants to dim the light. The same cover protects shrimplets. See best plants for a shrimp tank and java moss.
• Substrate: corys sift the bottom with sensitive barbels, and Seriously Fish warns that dirty or poor conditions can lead to barbel infections. Keep the substrate clean and avoid sharp gravel; fine sand is the classic choice for corys. See best substrate for shrimp.
• Filter: a sponge filter or a pre-filter sponge keeps shrimplets out of the intake and suits these small fish. See shrimp-safe filters.
• Maturity: add fish to a fully cycled, established tank. See how to cycle a shrimp tank.

Feeding two bottom grazers

Pygmy corys and shrimp both pick food off the bottom and plant leaves, so plan feedings so neither misses out:

• Size matters. Seriously Fish says food must be small enough for their tiny mouths: small or crushed dried foods plus small live and frozen foods such as daphnia and baby brine shrimp. Aquarium Co-Op says frozen bloodworms are often too big, and lists nano pellets, freeze-dried tubifex, sinking wafers and gel food as favorites.
• Spread it out. Seriously Fish says pygmies won't compete well for food with larger tank mates, Aquarium Co-Op says they aren't fast eaters, and Practical Fishkeeping notes that fish usually beat shrimp to food. Drop food in two or three spots so both get a share.
• Don't rely on leftovers. Seriously Fish says corys won't thrive on scraps that fall past other fish; always feed sinking foods for them.
• Clear uneaten food. Extra food fouls the substrate the corys forage in. See best shrimp food and what shrimp eat.

How to add pygmy corys to a shrimp tank

• Shrimp first. Practical Fishkeeping suggests letting a shrimp colony build up before adding fish.
• Quarantine the fish elsewhere. Practical Fishkeeping warns that many fish medications aren't safe for invertebrates, so treat fish in a separate tank. See how to quarantine and copper and shrimp.
• Add a full group at once, slowly acclimated, so they school and settle instead of hiding.
• Net gently. Seriously Fish notes corys have sharp fin spines that snag in nets; a cup or a fine, soft net works better.
• Keep water changes shrimp-sized. Practical Fishkeeping says big fish-style water changes can upset shrimp. See shrimp tank water changes.

Breeding: fish and shrimp in the same tank

Pygmy corys can breed in a home aquarium. Aquarium Co-Op says females lay single sticky eggs about 1 mm across on moss or floating-plant roots, and the eggs hatch in about 2 to 5 days; Seriously Fish says the adults will eat eggs given the chance. An interesting overlap: Seriously Fish notes that some breeders add cherry shrimp to egg-hatching containers, because the shrimp eat fungused eggs and leave healthy ones alone. Your shrimp will keep breeding in the display tank too, just with fewer survivors than in a shrimp-only tank. See baby shrimp care.

Common mistakes

• Keeping only two or three, which leaves them shy and hiding.
• Mixing them with larger fish that bully them or eat them.
• Relying on shrimp food or scraps to feed the corys.
• Letting the substrate get dirty, which risks barbel damage.
• 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

Can pygmy corydoras live with cherry shrimp?

Yes. They are peaceful, tiny and spend much of their time in midwater. Aquarium Co-Op says they won't bother adult dwarf shrimp, though they may accidentally eat a baby shrimp while foraging.

Will pygmy corydoras eat baby shrimp?

Occasionally. Losses are usually small in a planted tank with moss, where shrimplets can hide, and a cherry shrimp colony normally keeps growing.

How many pygmy corydoras should I keep?

At least 6, preferably 10 or more (Seriously Fish); Aquarium Co-Op suggests 8 to 12. Bigger groups are bolder and school more.

What size tank do pygmy corys and shrimp need?

About 10 gallons or larger. Seriously Fish says a large group fits in an 18 × 12 × 12 in tank (about 11 gallons).

What water works for both?

Pygmy corys like 72 to 79 °F and pH 6.4 to 7.4 with soft to moderately soft water. Cherry shrimp overlap at about 72 to 78 °F, pH 6.4 to 7.4 and GH 4 to 8. Keep it stable.

Do pygmy corys compete with shrimp for food?

They can, since both feed on the bottom. Use small sinking foods and drop them in a few places so both get a share.

Should I add pygmy corys or shrimp first?

Shrimp first. Practical Fishkeeping suggests letting the shrimp colony build up before adding fish, and the tank should be fully cycled and mature.

Sources: Seriously Fish, Gastrodermus pygmaeus (pygmy cory) (Gastrodermus pygmaeus, long known as Corydoras pygmaeus; Rio Madeira basin, Brazil; small tributaries, creeks, pools, flooded forest among marginal vegetation and roots; 30 mm SL; 45 × 30 × 30 cm, about 41 L/11 US gal for a large group; 22–26 °C, pH 6.4–7.4, hardness 2–15 but preferably below 8; needs steady pH and temperature; dim light, heavily planted, driftwood, floating plants; small dried foods plus sifted daphnia and Artemia nauplii; very peaceful, easily intimidated, won't compete for food with larger fish; keep with tiny species including small freshwater shrimp; midwater swimmer; group of at least 6, preferably 10+; adults eat eggs; cherry shrimp used to clean fungused eggs in hatching containers; barbel infections in dirty conditions; won't thrive on scraps, feed sinking foods; sharp fin spines catch in nets; confused with G. hastatus); Aquarium Co-Op, Care guide for pygmy corydoras (about 1 in; hovers midwater; pH 6.4–7.5, 72–78 °F, moderately soft; plants and hardscape for cover, perched on anubias and driftwood; 10 gallons or larger for a school of 8–12; peaceful with nano fish; won't bother snails or adult dwarf shrimp, may accidentally eat a baby shrimp while foraging; small sinking foods, bloodworms often too big, nano pellets, freeze-dried tubifex, sinking wafers, gel food; single sticky eggs about 1 mm on java moss or water sprite roots, hatch in 2–5 days; habrosus/hastatus/pygmaeus ID); Practical Fishkeeping, What can I keep with shrimp? (corys among fish whose shrimp losses can be reduced with plants, hiding places and well-fed fish; shrimp may hide and breed less with fish; fish beat shrimp to food; let the colony build before adding fish; large fish-style water changes upset shrimp; medications often not invertebrate-safe; shrimp-only best for breeding); The Shrimp Farm, Red rili shrimp tank set-up and care (Neocaridina range used for comparison: pH 6.2–8.0, 65–85 °F, GH 4–8).