Cichlids · Cleithracara maronii

Keyhole cichlid care guide

Also called: Keyhole, Aequidens maronii

The keyhole cichlid is a small, shy South American cichlid named for the dark keyhole-shaped spot on its side. It's one of the few cichlids that suits a calm community tank. Keep a pair in at least 29 gallons (110 L) with plants and plenty of cover.

Keyhole cichlids need a tank of at least 29 gallons (110 L), a group of 2 or more, and water at 22–26°C (72–79°F) with a pH of 6–7.5. They grow to about 10 cm (3.9 in) and are peaceful.

Plan a tank with keyhole cichlidsSee all tank mates

Keyhole cichlid quick facts

Scientific nameCleithracara maronii
FamilyCichlidae
OriginCoastal creeks of the Guianas and the lower Orinoco delta, northern South America (most sold are farm-bred)
Adult size10 cm (3.9 in)
Minimum tank29 gallons (110 L), at least 75 cm (30 in) long
Temperature22–26°C (72–79°F)
pH6–7.5
Hardness (GH)3–12 dGH
Group size2 or more (pair)
TemperamentPeaceful
Swims atMiddle
DietOmnivore
Care levelEasy
Lifespan8–10 years
Safe with shrimp?No, eats shrimp
Safe with plants?Yes

Tank setup

A pair needs at least a 29-gallon (110 L) tank, about 30 in (76 cm) long, and a 3 ft (90 cm) tank is better. Give it lots of cover: driftwood, leaf litter, caves and live plants. Dim light or floating plants help this shy fish feel safe. It rarely digs, so it suits a planted tank.

How many keyhole cichlids in a tank?

The smallest common tank that suits keyhole cichlids is a 29 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.

TankKeyhole cichlids (alone)
3 gallonToo small
5 gallonToo small
10 gallonToo small
15 gallonToo small
20 gallonToo small
20 gallon longToo small
29 gallon2–7
40 gallon2–10
55 gallon2–14
75 gallon2–19
125 gallon2–33

What you need for keyhole cichlids

Sized for a 29 gallon tank, the smallest common size that suits a group of 2 keyhole cichlids. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.

Tank and equipment

Food and extras for keyhole cichlids

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Water parameters

Keep it at 22–26°C (72–79°F), pH 6.0–7.5 and soft to moderately hard water. Wild fish come from soft, tea-stained creeks, but farm-bred fish adapt to most tap water. Only add it to a fully cycled tank, and change 25–30% of the water every week to keep nitrate low.

Best tank mates for keyhole cichlids

These popular species share keyhole cichlids' water needs and temperament. See the full list of 97 good matches.

Avoid keeping keyhole cichlids with

  • Cherry shrimp: Keyhole cichlid eats small shrimp like cherry shrimp.
  • Oscar: Oscar can eat keyhole cichlids: they're small enough to fit in its mouth once it's grown.
  • Chili rasbora: Keyhole cichlid can eat chili rasboras: they're small enough to fit in its mouth once it's grown.
  • Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful keyhole cichlids.
  • Convict cichlid: Convict cichlid is aggressive and will bully or injure peaceful keyhole cichlids.
  • Discus: They need different temperatures: Keyhole cichlid 22–26°C (72–79°F), discus 28–30°C (82–86°F).

Feeding

An easy-going omnivore that takes most foods. Use a quality small cichlid pellet or flake as the base. Add frozen or live bloodworms, brine shrimp and daphnia a few times a week, plus some vegetable-based food for variety.

Behavior

Peaceful and timid, and only feisty when guarding eggs or fry. A school of small, calm fish swimming in the open helps it feel safe and come out more. Avoid pushy or territorial cichlids, which will bully it. Very small fish and dwarf shrimp can end up as food.

Breeding

Easy to breed. Young fish pair off on their own, and a pair lays up to about 300 eggs on a flat stone, a piece of wood or a broad leaf. The female mostly tends the eggs while the male guards the area, and both look after the fry, sometimes for months. Young pairs often eat their first few batches but usually improve with practice.

Tips from experienced keepers

  • Keep a pair, or raise a few young fish and let them pair off. A single keyhole tends to hide more.
  • Add a school of peaceful tetras or rasboras as dither fish. Seeing them out in the open makes keyholes bolder.
  • When scared, keyholes turn dark and blotchy to blend in. If yours stay that way, add more cover or remove pushy tankmates.
  • Don't house keyholes with convicts, Jack Dempseys or other aggressive cichlids.
  • Skip dwarf shrimp and nano fish. Even this gentle cichlid will eat what fits in its mouth.

Frequently asked questions

Are keyhole cichlids good for community tanks?

Yes. They are among the most peaceful cichlids and live well with calm fish like tetras, rasboras, corydoras and small plecos. Avoid aggressive tankmates, very tiny fish and dwarf shrimp.

How big do keyhole cichlids get?

Most reach about 4 inches (10 cm) in a home aquarium, and they grow slowly. Males are usually a little larger than females.

What size tank do keyhole cichlids need?

A pair needs at least 29 gallons (110 L), and a 3 ft (90 cm) tank is better. Go bigger if you want to keep them with other fish or let them raise fry.

Sources

We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.