A Complete Keyhole Cichlid Overview

keyhole cichlid

Keyhole Cichlid – Tankmates, Care, Habitat and Details You Need!

This overview covers the Keyhole Cichlid, one of the most peaceful and reclusive cichlids.

Keyhole Cichlid: Short Profile

FeatureKeyhole Cichlid Profile
Synonyms:Acara maronii, Aequidens maronii
Aquarium size:160 l / 100cm 240 l / 120cm 360 l / 140cm 600 l / 160cm 1000 l / 200cm 2000 l / 250cm 5000 l / 350cm
Number:paired group of 3 or more animals
Socialization:Community with no tiny fish.
Temperature:22 ° C  – 28 ° C 
Origin:South America
Distribution:French Guiana, Guyana, Suriname, Venezuela, and possibly Trinidad & Tobago.
Final size:10-15cm
Aquarium region:center
Special:for beginners
Water hardness:soft medium hard
pH range:Will acclimatise to a wide range of conditions. pH: 5.5-7.5, dH: up to 18 degrees.
Feeding:Dry food, frozen food & live food carnivor omnivor (omnivores)
Gender differences:Males larger Males with extended (anal &) dorsal fin
Propagation:Substrate spawners
Lighting:Dim (can be brighter if diffused by plants).
Sexual DimorphismIn mature fish, the males are larger and develop extended anal and dorsal fins.

Keyhole Cichlid: Complete Profile

FeatureKeyhole Cichlid Profile
ClassificationActinopterygii (ray-finned fishes) > Perciformes (Perch-likes) > Cichlidae (Cichlids) > Cichlasomatinae
OriginKeyhole cichlids (Cleithracara maronii) originally come from northern South America . They live there in rivers near the coast, which are rich in animal plankton.
EtymologyCleithracara: Greek, kleithro = to close + tupí guaraní, Acará, the name of a fish in Amazonas river; maronii: Named for its type locality, the Maroni River.
EnvironmentFreshwater; brackish; benthopelagic; pH range: 6.0 – 8.0; dH range: 6 – 20. Tropical; 22°C – 25°C
DistributionSouth America: Trinidad (impersistent), Orinoco River basin (delta), rivers from Barima River (Guyana) to Ouanary River (French Guiana).
BiologyInhabits small creeks in the coastal zone, which have clear water and little current and is rich in decaying wood. Feeds on worms, crustaceans and insects. When faced with danger, this fearful species fix itself against a log adapting its color pattern to the substrate. Parents take care of the spawned eggs, numbering about 400, which are laid down on a flat stone.
Life cycle and mating behaviorSpawns on hard substrate; produces up to 600 eggs; both parents guard eggs and larvae.
Keyhole Cichlid aggressionThe peaceful cichlids are very peaceful, even rather scared. In the aquarium hobby it is often socialized with other peaceful fish and is also very suitable for community aquariums.
Cleithracara maronii can be kept in pairs or in a group.
Aquarium conditionsIn order to keep Cleithracara maronii (Keyhole cichlids) as species-appropriate as possible, we recommend creating the following conditions. Especially when specifying the minimum size, we ask you to note that the optimal conditions may only be possible in significantly larger aquariums.

Water temperature: 22 ° to 26 ° C
pH value: 6.0 to 7.5
Total hardness: 5 ° to 19 ° dGH
Minimum aquarium size: 250 liters
Cleithracara maronii grows up to 13 cm. Due to its size, it needs a small aquarium (from 112l). As a rule, Cleithracara maronii can be found in the lower area of the aquarium. The substrate should consist of sand and be provided with flat, smooth stones for spawning. Aquarium plants as a place to hide or retreat contribute to the well-being of the animals. Stone structures or roots should be offered as a facility.

Cleithracara maronii is an open breeder, where the mostly transparent spawn is deposited so that other animals can see it. It is possible to breed your own in the aquarium. Cleithracara maronii feeds in its natural environment carnivorous, ie mainly on animal food.
Ideal maintenance conditions• The aquarium should be mature and at least 3ft long (preferably larger) with a soft sand substrate.

• Make sure there are enough hiding places amongst tangles of driftwood, rocky caves, and robust planting, including some floating species to help diffuse the light.

• Install efficient filtration that generates gentle water movement

• Carry out frequent partial water changes to keep nitrate at a minimum

• Keep juvenile Keyhole Cichlids in good-sized groups. However, as they mature, pairs will form naturally, and they may become much more territorial if they intend to spawn. This should not cause too much of an issue in spacious aquaria.

• Make sure you add peaceful and small-medium size tank mates (large enough not to be eaten, yet small enough not to harass these peaceable cichlids). Ideal companions could include Corydoras catfish, hatchetfish, pencilfish, tetras, and suckermouth catfish. The presence of such ‘dither fish’ should help encourage these shy cichlids to venture out into the open a little more. When Keyhole Cichlids sense danger, they are capable of dramatic colour change, quickly taking on a dark cryptic pattern, blending into the substrate and immediate surroundings. Take care when carrying out maintenance on the aquarium, as these fish are so easily startled.

FeedingKeyhole Cichlids are omnivorous. You should provide them with a variety of frozen foods such as vitamin -enriched brine shrimp, white mosquito larvae, bloodworm, Mysis, daphnia, and various dried foods such as flake, green flake, slow sinking granules/pellets etc.
Keyhole Cichlid BreedingKeyhole Cichlids are substrate spawners. A typical spawning site will be a pre-cleaned flat piece of rock/wood/broad leaf, or even the aquarium glass. When ready, the female will swim over the spawning site in a series of ‘dry runs’, after which she will begin depositing eggs in small batches.

The male immediately follows behind her and fertilises them, and this is repeated until several hundred eggs are laid/fertilised. The female then guards the eggs whilst the male patrols the perimeter. The eggs should hatch within 3 days, and the wrigglers will be free-swimming just a few days later.

At this point, the fry can be offered newly hatched baby brineshrimp (Artemia nauplii) and moved on to larger foodstuffs as they grow. It is not unusual for a young, inexperienced pair to eat their first batch of eggs; however, they should quickly get the hang of things on subsequent breeding attempts.

Keyhole Cichlid: Videos

Keyhole Cichlid: Diseases and Infections

Ichthyophthirius multifiliis


The pathogen is a ciliat (ciliate) called Ichthyophthirius multifiliis.

The so-called hawker looks for a host fish and penetrates the fish skin. Sitting under the mucous membrane, it feeds on cell debris and lymph. Depending on the temperature, it stays there for 18 hours to 80 days.

When it has grown to around 1 mm, it breaks away from its host and falls to the ground. There a solid capsule forms around the parasite, in which it multiplies up to 1000 times through cell division. Break open the shell the swarmers are released and have to find a host fish within 48 hours. Treatment with appropriate preparations is possible during this time. The cycle starts again.


  • The fish infected with Ichthyo have white spots on their bodies, fins and gills.
  • The fish rub against objects and have irregular breathing.
  • The fins are “pinched together” and the fish lose weight more and more.

The Ichthyo is contagious and can affect all fish in the aquarium in a short time. Secondary infections caused by bacteria and fungi often occur along with Ichthyo.


Treatment against Ichthyo is possible with good results. For this purpose, agents containing malachite green are mostly used. Malachite green is an effective product for external parasite and fungal diseases.

When used together with formaldehyde, its activity is increased, so less malachite is needed.

Some drugs also contain methylene blue. Methylene blue is a strongly coloring, crystalline substance with an antiseptic and disinfectant effect.

In the early phases of skin and gill infections, but also in the case of mild bacterial and fungal skin problems, methylene blue is a tried and tested drug that is widely used due to its favorable tolerance.

Treatment must be carried out as quickly as possible, as the kidneys fail as a result of the disease, resulting in the death of the fish.

Treat the entire tank as it can be assumed that the other fish are also infected. The filter must run along with the treatment, as there are swarmers in the filter. Medicines can be obtained from specialist shops.



Flagellates are unicellular, eukaryotic organisms that move with whip-like cell extensions, flagella.

Flagellates are microorganisms that move through one or more flagella. Flagellates of the genera Hexamita and Spironucleus are normally found in small numbers in the intestines of fish without damaging them. Only when they can spread en masse in the intestines of the fish can one speak of a pathological infestation.

The cause of the disease is not the presence of flagellates, but the factors that lead to mass spread and weaken the fish.

These can be:

  • other diseases
  • unsuitable low-fiber food
  • incorrect water values

Therefore, in addition to the drug treatment of the disease, the causes must be found and eliminated, which led to a weakening of the fish and thus enabled the parasites to multiply.


  • The sick fish change their usual behavior, become shy and sluggish
  • The cichlids change their color to dark
  • They eat poorly or not at all.
  • Their stomach is initially – not in all cases – inflated and then emaciated.
  • Their droppings are white and transparent and form long threads.
  • The cause is an inflamed intestine and a withdrawal of nutrients by the parasites that appear in large numbers.
  • Often whitish, hole-like appearances can be observed in the head region of the animals at the same time. One then speaks of the hole sickness.


Adequate treatment is possible with preparations that contain the active ingredients metronidazole or nitroimidazole and are available from specialist aquarists.

Metronidazole has a killing effect on pathogens that do not need oxygen to live (anaerobes). The active ingredient inhibits the cell metabolism of the bacteria and thus prevents their further reproduction.

In addition to the medical treatment of the disease, the cause must also be found and eliminated, which led to a weakening of the fish and thus enabled the parasites to multiply.

Fin rot


Bacterial fin rot is a disease in which the fine tissue of the fin membranes is attacked by bacteria of the genera Aeromonas, Pseudomonas and Vibrio.

This disease occurs more frequently in tanks with poor water values.

This could be a bracket that is too cool, an incorrect pH value or insufficient water change.

In addition, fish can show symptoms of fin rot even in an intact aquarium.

This is often the case when an oppressed animal is under constant stress.

In most cases, sick animals do not die directly from the disease, but are downright chased to death by their conspecifics.


  • At first, milky opacities appear on the fin edges.
  • As the disease progresses, the fins fray more and more. #
  • They dissolve more and more until finally only rotting fin stumps are left.
  • The fish are lethargic and attacked by aggressive, healthy conspecifics.
  • Often there is also mold formation (Saprolegnia, Achlya) and the rotting of the fins is accelerated.


First, the sick animal should be caught and transferred to a separate tank. This protects the healthy animals from infection and the sick animal from attacks by the healthy animals.

Moving the sick animal into a pool with a higher water temperature (approx. 26-29 ° C) often brings success.

Salt can also be added. If the disease has progressed too far or if there is also mold formation, there are good remedies for fin rot in specialist shops.

For treatment, the infected fish are quarantined and treated with drugs that kill bacteria. We strongly advise against using it in the aquarium because antibiotics kill the filter bacteria and some fish and invertebrates can be sensitive.

In addition to drug treatment of the disease, the cause of the disease must also be sought and eliminated.

Other Diseases

You will find an overview of other diseases HERE

Keyhole Cichlid: People Also Ask

Are Keyhole cichlids aggressive?

Keyhole cichlids are generally quite non-aggressive, shy, and peaceful. However, you should not keep them with other aggressive fish species.

How do you breed Keyhole cichlids?

Keyhole cichlids often lay their eggs on a flat surface that they have cleaned in advance. Each breeding can result in upwards to 300 eggs. After the eggs have hatched, both the male and the female Keyhole Cichlids will then work together to protect the young. The female usually watches the eggs while the male guard a larger territory around the eggs.

How fast do Keyhole cichlids grow?

Keyhole cichlids tend to grow slower than other cichlids. In 3 months they might grow from 3/4 to 1 inch.

How long do Keyhole cichlids live?

With proper aquarium maintenance, the average lifespan of the Keyhole cichlid is expected to be at least 7 years but some specimens may reach an older age.

Should Keyhole cichlids be kept in groups?

Keyhole cichlids tend to be a bit aggressive. They are generally not community fish and only do best in species tanks. Keeping cichlids from the same region together is also recommended.

What temperature is best for Keyhole cichlids?

Try and maintain the water temperature between 78 and 82 degrees Fahrenheit.
Tropical fish need warm water that’s between 78 and 82 degrees Fahrenheit (23-28 Celsius). Choose an aquarium heater with 5 watts of power for each gallon of water in the aquarium.

How many times a day should I feed my Keyhole cichlids?

You should feed your Keyhole cichlids 2 to 3 times a day. The rule is to feed them as much as they can eat in about 2 minutes without leaving anything behind. It’s still very important not to overfeed them. Your cichlids should always appear to be hungry when it’s time to eat.

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