Keyhole Cichlid
Cleithracara maronii
An exceptionally peaceful, shy cichlid named for its keyhole marking.
| Difficulty | Beginner |
| Min. Tank Size | 110 L |
| Temperature | 22.0–28.0 °C |
| pH Range | 6.0–7.5 |
| Max Size | 10.0 cm |
| Lifespan | 7-10 years |
| Diet | Omnivore |
| Temperament | Peaceful |
Overview
The Keyhole Cichlid (Cleithracara maronii) is an exceptionally peaceful, shy cichlid named for its keyhole marking. It is one of the most recognisable members of the cichlids group kept by Australian aquarists, valued for its appearance, manageable adult size of around 10.0 cm and its peaceful nature.
This guide covers everything you need to keep the Keyhole Cichlid successfully - ideal tank size and setup, water parameters, diet, suitable tank mates, breeding, how to tell males from females, and the health problems to watch for. Rated Beginner to care for, it can live for roughly 7-10 years when its needs are met.
Natural Habitat & Origin
This cichlid comes from the warm rivers, streams and floodplains of South America (and, for some species, West Africa), where it forms pairs and defends a territory among roots, rocks and leaf litter. It is an intelligent fish that rewards a thoughtfully aquascaped, stable tank.
Understanding where a fish comes from is the shortcut to keeping it well: matching the temperature, water chemistry and amount of cover it evolved with is far more effective than fighting against its nature.
Tank Size & Aquarium Setup
Provide a minimum of 110 litres for the Keyhole Cichlid. A roomy, well-planted tank lets a pair settle and behave naturally.
Fit a lid to prevent jumping and to keep the tank warm and stable.
Live plants, driftwood and some shaded retreats give the fish security and show off its colours against a natural backdrop.
Mature, well-cycled biological filtration is essential before adding any fish. Match the filter's flow to the fish - moderate for most, stronger and more oxygenated for hillstream and riverine species.
Water Parameters
Keep the Keyhole Cichlid in stable water at 22-28 °C with a pH of 6.0-7.5. It is adaptable across a moderate range, so stability matters more than hitting an exact number.
Test your water regularly: ammonia and nitrite must always read zero, and nitrate should be kept low (ideally under 20-40 ppm) with routine partial water changes. Sudden swings in temperature or chemistry cause far more illness than water that is slightly 'wrong' but stable, so always dechlorinate and temperature-match new water.
Diet & Feeding
The Keyhole Cichlid is an omnivore and an easy feeder. A quality flake or micro-pellet forms a good staple, enriched several times a week with frozen and live foods such as bloodworm, daphnia and brine shrimp for colour and condition.
Feed small amounts once or twice a day - only as much as the fish clears in a minute or two - and consider one fasting day a week. Overfeeding is the single most common cause of pollution and disease in home aquariums.
Temperament & Tank Mates
The Keyhole Cichlid is an excellent peaceful community fish. It mixes happily with other calm species that share its temperature (22-28 °C) and pH (6.0-7.5) needs, are too large to be eaten, and are not large enough to eat it.
Breeding
The Keyhole Cichlid is an open substrate spawner that forms pairs and lays eggs on a cleaned flat rock or leaf. Both parents guard the eggs and shepherd the fry, showing impressive parental care.
Even if you do not plan to breed it, understanding this behaviour helps you recognise it in the tank and respond appropriately - for example by adding cover for fry or by giving a guarding pair some space.
How to Tell Males from Females
In many of these cichlids the male is larger with longer, more pointed fins and brighter colour, while the female is smaller and rounder; some species show clear breeding colours that make pairing easier.
Common Health Problems
Like most aquarium fish it is susceptible to white spot (ich), fin rot and fungal infections, almost always triggered by stress or poor water quality. It is sensitive to nitrate and bacterial infections, so frequent water changes and a mature tank are essential. Quarantine new arrivals for 2-4 weeks to keep your main tank disease-free.
Prevention is far easier than cure: keep water pristine, avoid overstocking and overfeeding, quarantine new arrivals for two to four weeks, and watch daily for early warning signs such as clamped fins, loss of appetite, flashing (rubbing on objects) or laboured breathing. Caught early, most problems are very treatable.
Is the Keyhole Cichlid Right for You?
The Keyhole Cichlid is a rewarding choice for beginners and experienced keepers alike, as long as you can provide at least 110 litres, water at 22-28 °C and pH 6.0-7.5, the right diet and suitable tank mates.
Get those basics right and you will enjoy a healthy, colourful Keyhole Cichlid for around 7-10 years. For tank planning, try our free aquarium tools, and browse our fish, plant and disease guides to build the perfect community.
