Keeping Keyhole Cichlids: Your Quick Care Guide

The keyhole cichlid (Cleithracara maronii) is a very nice, but not very popular freshwater tank fish. Most of pet shops and breeders ignore it because of its timidity and not very bright coloring and this is a big mistake. Since this is a peaceful, clever, good-tempered fish unlike the majority of other cichlid species, which are brighter, but much more aggressive.

Habitat in the wild

The keyhole cichlid (Cleithracara maronii) belongs to the family Cichlidae. The family Cichlidae is a diverse group of freshwater fish found in various regions around the world, with a majority of species residing in Africa, Central and South America, and a few in Asia.

Cichlids are known for their unique and often colorful appearances, as well as their intriguing behaviors, which include parental care for their offspring and territoriality. They come in various sizes, from small species suitable for home aquariums to larger ones found in natural habitats.

This is an endemic of tropical South America, within Orinoco river estuary area starting from Barima river (Guyana) to Ouanary river (French Guiana). This species is the only one from Cleithracara kind.

The keyhole cichlid inhabits numerous slow rivers and streams flowing in tropical forests. Bottom of these waters as a rule is covered with fallen leaves, branches, various fruit from trees. Plenty of organics on the bottom usually makes water rich brown colored due to high concentration of tanning agents.

Wild keyhole cichlid species are hardly ever seen on sale, most of cichlids you see in pet shops were grown in fish hatcheries and private farms.



How big do keyhole cichlids get? The keyhole cichlid is a relatively small fish compared to some other cichlid species. Males can be up to 7-10 cm (4 inches) long, they are a bit larger than females and they have longer rays of dorsal and anal fins; these of adult species reach the end of their tail fin. Their relatively small size makes them suitable for medium-sized aquariums, and they can be kept with a variety of peaceful fish in a community setup.


In captivity, keyhole cichlids have a typical lifespan of about 5 to 10 years. However, the lifespan can vary depending on several factors, including the quality of care, water conditions, diet, genetics, and overall health of the fish.


A dark stripe that starts at the dorsal base goes through the fish eye up to the bottom of its gill cover. In the center of the body closer to its tail there is a group of dark spots that resemble a keyhole. Due to this the fish got its name.

Scientific NameCleithracara maronii
Common NameKeyhole Cichlid, maroni cichlid
OriginSouth America (Amazon River basin and tributaries)
SizeUp to 4-5 inches (10-13 cm)
Lifespan5-10 years (in captivity)
TemperamentPeaceful, relatively non-aggressive
Difficulty LevelEasy to moderate
Aquarium Size30 gallons (113 liters) or larger
Water Conditions– Temperature: 75-82°F (24-28°C)
– pH: 6.5 – 7.5
– Water hardness: 5-12 dGH
DietOmnivorous – High-quality pellets, flakes,
and live/frozen foods (brine shrimp, bloodworms,
daphnia, etc.)
Tank Setup– Plenty of live plants
– Hiding spots (driftwood, rocks, caves)
– Substrate: Soft sand or fine gravel
CompatibilityPeaceful community fish (avoid aggressive species)
Breeding BehaviorSubstrate spawners, exhibit parental care

Difficulties in keeping

The keyhole cichlid is neither large nor aggressive. It is quite undemanding and has very interesting behavior. It can be recommended even for the beginners, but still you have to keep in mind that this is a cichlid species and it is hardly suitable for community tanks with small sized fishes.

Care and keeping in a tank

Tank size

The recommended tank size for keyhole cichlids depends on how many individuals you plan to keep and whether you want to include other tank mates. Keyhole cichlids are relatively small fish, but they still need enough space to swim comfortably and establish territories. Recommended tank volume for one couple starts from 30 gallons (113 liters). Keyhole cichlid is a monogamic fish, it forms couples. When keeping the fish in a school you should bear in mind that the fish is a territory dependent one and there has to be a sufficient number of shelters in the tank, that will divide it into some areas.

If you plan to keep more keyhole cichlids or add other peaceful community fish as tank mates, you’ll need a larger tank to accommodate the increased bioload and ensure harmony among the fish. For a community setup with keyhole cichlids, you should consider a tank size of 50 gallons (189 liters) or more, depending on the number and size of the fish you intend to keep.

Tank decor

The keyhole cichlid requires large number of shelters: stones, snags, flower pots, ceramic tubes, coconut shells. The fish is fearful and timid and if there are a lot of shelters in the tank it’ll help to decrease the stress.

Since the keyhole fish doesn’t dig the tank bottom substrate, it can be kept in most of amateur planted tanks.

The keyhole cichlid looks best in a tank simulating its natural biotope – small grained sand on the bottom, tree leaves, roots and snags. Several large flat stones you put may become future spawning substrate for the fish.

Water parameters

It has quite high requirements in terms of the tank water quality and composition – it should be soft and acidic. The fish originates from the tropical areas, so the tank water temperature has to be within 22-26 °C (71,6-78,8°F), soft or of average hardness, pH 6,5-7,2.


Presence of efficient filtration system and regular renew of some portion of tank water with fresh one as well as timely cleaning of the tank bottom substrate is a must. However, keep in mind that powerful filters quite often create excessive water flow, which fishes that used to dwell in slow waters don’t like.


Keyhole cichlids are omnivorous fish, meaning they eat a variety of foods, including both plant matter and animal-based foods. The keyhole cichlid feeds on worms, crustaceans, larvae and insects. In a tank you can successfully feed it with live, dry and frozen food.

Here are some key components of a suitable keyhole cichlid diet:

  1. High-quality pellets: Commercial cichlid pellets designed for omnivorous species are a good staple food. Look for pellets that contain a mix of plant-based and protein-rich ingredients.
  2. Flakes: High-quality flake foods formulated for cichlids can also be offered as part of their regular diet. These can contain a variety of nutrients to support their dietary needs.
  3. Live and frozen foods: Keyhole cichlids enjoy live and frozen foods, which mimic their natural diet. Offer them treats such as brine shrimp, bloodworms, daphnia, and mosquito larvae. These foods are rich in protein and can enhance their coloration and overall health.

It’s essential to feed keyhole cichlids in small portions multiple times a day, as they have small stomachs and benefit from more frequent meals.

Tank mates

This is a small, timid fish that prefers hiding if it feels danger. It’s better to keep it in a school of 6-8 species without large and aggressive tank mates. But the tank should be roomy enough and have enough of shelters.

It’d be perfect to keep the keyhole fish in biotope with the species that dwell together with it in the wild (angelfish, for example). But it can be another species, like bolivian ram, dwarf gourami, betta, kribensis, neon tetra . The fish doesn’t demonstrate aggression towards its tank mates if they are at least several centimeters long.

It becomes aggressive only during the spawning process while protecting the offspring. Therefore, maximum of the aggression the keyhole cichlid demonstrates is to ward off other fishes from their territory.

Gender differences: male vs female

It is impossible to tell between the juveniles and young species, but as for the adult males – they are sufficiently larger than the females and they have larger dorsal and anal fins.

Keyhole cichlids exhibit sexual dimorphism, which means there are visible differences between males and females. While these differences may not be apparent when the fish are very young, they become more pronounced as they mature.

Here are the main differences between male and female keyhole cichlids:

  1. Size: In general, male keyhole cichlids tend to be slightly larger than females. Fully grown males can have more elongated bodies and are often more robust.
  2. Coloration: The coloration of male and female keyhole cichlids can differ significantly. Males usually display more intense and vibrant colors, especially during breeding periods or when they are trying to attract a mate. They may have brighter yellow, blue, and black markings on their bodies, fins, and operculums (gill covers). Females, on the other hand, may have less intense coloration and may appear duller.
  3. Keyhole Marking: The prominent keyhole-shaped marking on the sides of keyhole cichlids is more pronounced in males. In some cases, the keyhole marking on females may be less distinct.
  4. Behavior: During the breeding season, male keyhole cichlids can become more territorial and may exhibit courtship behaviors, such as digging and defending a spawning site. Females may also show increased aggression during this time, particularly when protecting their eggs or fry.

If you are planning to keep keyhole cichlids and want to ensure a harmonious community, it’s best to keep a group of several individuals rather than just one pair. This way, any aggression or territorial behavior can be dispersed among the fish, and they are more likely to form a balanced social structure.


Adult keyhole cichlid male and female species create a constant couple that they keep even after the spawning is over. A flat stone, wide leave of a tank plant or a glass surface where they stick their eggs can serve as a place for spawning. The female stays near the clutch to guard it and the male guards their territory.

The parents take care of their offspring after the juveniles hatch and it can last for several months. We should mention that inexperienced couples quite often eat their fist offspring, especially if they feel threatened by other fishes.

In an overcrowded tank the chances are high that the offspring dies even when guarded by both the male and female species, therefore it’s desirable to put the fish into a separate tank for spawning.