Cardinal tetras with shrimp

By the Shrimp Tank Hub editorsUpdated Oct 27, 2026Research-based

The cardinal tetra (Paracheirodon axelrodi) is the neon tetra's bigger, redder cousin. Maidenhead Aquatics says its German name, Red Neon, sums up the main difference: a red belly that the neon lacks. It comes from forest streams of the rio Negro and Orinoco basins in Brazil, Colombia and Venezuela (Seriously Fish). Seriously Fish says it is now bred commercially on a large scale, but a large share of the fish sold are still wild-caught, some through community projects such as Project Piaba. Maidenhead Aquatics says most cardinals in shops are captive-bred, and notes that buying wild fish can support conservation of their rainforest habitat.

Cardinal tetra at a glance

Will cardinal tetras eat shrimp?

• Adult shrimp: no, in practice. Aquarium Co-Op's cherry shrimp tank-mate guide pictures cardinal tetras living with red cherry shrimp, and says nano fish with tiny mouths pose little threat to full-grown cherry shrimp. In Practical Fishkeeping, Neale Monks answers a reader with eight cardinals that mixing small tetras with cherry shrimp can work up to a point if there are plenty of hiding places.
• Shrimplets: expect losses. Aquarium Co-Op calls cardinals micropredators that eat tiny crustaceans in the wild, and Neale Monks warns that pretty much any active fish, even a small tetra, sees hatchling shrimp as food. He adds that male cherry shrimp, being smaller and shyer, fare worse than the bolder females.
• Eggs and berried females: safe. Shrimp carry their eggs under the tail.

Because cardinals are a little bigger than neons, our reading is that the shrimplet risk is at least as high. For smaller options, compare neon tetras with shrimp, green neon tetras with shrimp and ember tetras with shrimp, or see the full cherry shrimp tank mates list.

Matching the water

Seriously Fish lists 73–84 °F, pH 3.5–7.5 and 1–12 dGH for cardinals, with wild fish doing best in more acidic, softer water. Cherry-type shrimp tolerate 65–85 °F, pH 6.2–8.0 and GH 4–8 (The Shrimp Farm). By our comparison:

• With cherry shrimp: about 75–80 °F, pH 6.5–7.2 and GH 4–8 overlaps both ranges. Ask whether the fish are tank-bred or wild; wild fish do best at the soft, acidic end and are less tolerant of worsening water (Seriously Fish). See shrimp tank pH and GH and KH explained.
• With crystal and other Caridina: the soft, acidic water suits cardinals, but crystal reds do best at about 68–74 °F (see crystal red shrimp care), mostly below the cardinal's 73 °F minimum, so it's a tight compromise at best.

Keep conditions steady at water changes. See shrimp tank water changes and shrimp water parameters.

Tank size and setup

• Size: a base of at least 24 × 12 in (Seriously Fish); Aquarium Co-Op suggests 15 to 20 gallons or larger for 8 to 10 cardinals.
• Mature, stable tank: wild cardinals handle deteriorating water poorly (Seriously Fish), so add them to an established tank. See how to cycle a shrimp tank.
• Dim light and plants: Seriously Fish suggests fairly dim light with Java fern, moss, Cryptocoryne and floating plants, plus sand, driftwood and leaf litter. Dense moss also gives shrimplets cover (Aquarium Co-Op). See java moss for shrimp and driftwood and botanicals for shrimp.
• Shrimp-safe intake: a sponge filter or pre-filter keeps shrimplets out of the filter (our suggestion). See shrimp-safe filters.

Keep a real school

Seriously Fish recommends a mixed-sex group of at least 8–10. Aquarium Co-Op says six is the common minimum for schooling fish but recommends 8–10 cardinals. Maidenhead Aquatics notes that wild cardinals often forage in groups of 5–15 before joining larger shoals. Females are rounder and a little larger than males (Seriously Fish). Cardinals live only about a year in the wild but much longer in aquariums (Seriously Fish, Maidenhead Aquatics).

Other good tankmates

Seriously Fish suggests similar-sized characins, hatchetfish, pencilfish, small catfish and small, non-predatory cichlids. Aquarium Co-Op adds corydoras, kuhli loaches, otocinclus and snails. Its cherry shrimp guide warns that dwarf cichlids do go after shrimp, so skip those in a shrimp tank (our reading). See pygmy corydoras with shrimp, otocinclus with shrimp, marbled hatchetfish with shrimp and dwarf pencilfish with shrimp.

Feeding both

Cardinals eat small invertebrates, crustaceans and algae in the wild (Seriously Fish). Aquarium Co-Op feeds crushed flakes, nano pellets, freeze-dried worms, Daphnia, frozen cyclops and baby brine shrimp; Seriously Fish adds bloodworm and mosquito larvae. Well-fed fish hunt less, so feed the tetras first, then drop sinking shrimp food in a planted corner (our suggestion). See best shrimp food.

How to add cardinal tetras to a shrimp tank

• Shrimp first. Practical Fishkeeping suggests letting the shrimp colony build up before adding fish.
• Ask if they are wild or tank-bred and acclimate slowly to your water. See how to drip acclimate.
• Watch shrimplet numbers for the first few weeks.
• 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

• Running the tank cool for shrimp, below the cardinal's 73 °F minimum.
• Expecting a shrimp colony to grow fast with a school of tetras hunting shrimplets.
• Adding wild fish to a new or unstable tank.
• Keeping only a few, which makes them shy.

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

Will cardinal tetras eat cherry shrimp?

Not adults. Aquarium Co-Op shows cardinals living with red cherry shrimp, but like most small tetras they will eat shrimplets (Practical Fishkeeping).

What is the difference between cardinal and neon tetras?

The cardinal has a red belly that the neon lacks, which Maidenhead Aquatics calls the main difference. Cardinals are also a little larger (Aquarium Co-Op).

What water do cardinal tetras need?

Seriously Fish lists 73 to 84 °F, pH 3.5 to 7.5 and 1 to 12 dGH. With cherry shrimp, aim for about 75 to 80 °F and pH 6.5 to 7.2.

How many cardinal tetras should I keep?

At least 8 to 10 (Seriously Fish, Aquarium Co-Op), in about 15 to 20 gallons or more (Aquarium Co-Op).

How big do cardinal tetras get?

About 1.4 inches (35 mm standard length) according to Seriously Fish, and up to 1.75 inches in aquariums according to Aquarium Co-Op.

Can cardinal tetras live with crystal shrimp?

The soft, acidic water suits both, but crystal reds prefer about 68 to 74 °F, mostly below the cardinal's 73 °F minimum, so it is a tight compromise.

Sources: Seriously Fish, Paracheirodon axelrodi (cardinal tetra) (rio Negro and Orinoco; commercially bred at scale, many still wild-caught, Project Piaba; wild fish less tolerant of deteriorating water; 35 mm SL; base 60 × 30 cm; dim light, Microsorum, Taxiphyllum, Cryptocoryne, floating plants, leaf litter; 23–29 °C, pH 3.5–7.5, 1–12 dGH; omnivore, small invertebrates and crustacea, bloodworm, mosquito larvae, Daphnia; generally peaceful, similar-sized characins, hatchetfish, pencilfish, small catfish, non-predatory cichlids; 8–10 mixed-sex; females rounder; virtually annual in the wild, longer in aquaria); Aquarium Co-Op, Care guide for cardinal tetras (up to 1.75 in, larger than neon and green neon; pH 4.0–7.5, soft to moderate hardness, 73–84 °F; 8–10 in 15–20 gallons or more; tankmates pencilfish, hatchetfish, corydoras, kuhli loaches, otocinclus, snails; micropredators of tiny crustaceans; crushed flakes, nano pellets, Daphnia, cyclops, baby brine shrimp); Maidenhead Aquatics (fishkeeper.co.uk), Cardinal tetra (3.5 cm; 23–27 °C; pH 4.0–7.0, dH 5–12; red belly the neon lacks; mostly captive-bred in shops, wild exports support conservation; forage in groups of 5–15; longer-lived in aquaria; flake, micropellets, small frozen foods); Aquarium Co-Op, Cherry shrimp tank mates (cardinal tetras pictured with red cherry shrimp; tiny-mouthed nano fish pose little threat to adult cherry shrimp; dense foliage hides babies; dwarf cichlids go after shrimp); Practical Fishkeeping, Can I safely add some shrimp? (cardinals with cherry shrimp can work up to a point with plenty of hiding places; smaller males shyer; any active fish, even a small tetra, sees hatchling shrimp as food); Practical Fishkeeping, What can I keep with shrimp? (build the colony first; 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 zones, shrimp-risk reading and stocking suggestions are our own.