Keyhole cichlid

Settle the tank before this cichlid goes in

Cleithracara maronii comes from slow, shaded blackwater streams, but the trade fish are mostly commercially farmed and adapt to ordinary near-neutral water. The requirement that survives translation into a home aquarium is stability. Seriously Fish states it should never be introduced to a biologically immature aquarium and is susceptible to deteriorating water quality; where maintenance or diet falls short, individuals can develop head and lateral line erosion or stunted growth. Cycle and settle the tank first — our guide to cycling a tank covers what "mature" means — and keep conditions steady rather than chasing the acidic extremes of its habitat. Hold a regular partial water-change routine with conditioned replacement water matched to the tank — deteriorating water is where this species fails first.

Keep the published 21-28 C, pH 4.0-7.5 and 2-15 dGH ranges as compatible-care boundaries, not targets to bounce between. Avoid high flow: position filter returns so the fish has calm areas. For structure, wood roots, branches, leaf litter and flowerpot-style caves all work; this species rarely digs, so a planted layout is safe, and a flat stone or broad leaf may later serve as a spawning site. Regular water testing matters more with this fish than an elaborate aquascape.

Peaceful means it loses the arguments

A gentle temperament is a liability in the wrong company. The species account warns this cichlid is naturally shy: when it detects danger it darkens noticeably and takes cover among plants, wood or leaf litter. Boisterous, aggressive or strongly territorial fish — and species needing harder water — are the ones to avoid, because a fish that spends its days hidden is also a fish that may not be feeding.

Useful company is the opposite: small, calm schooling fish of similar water needs act as a visible all-clear cue that encourages it out into the open. A small group of a species such as the neon tetra is a classic example to research; check adult size, water range and feeding speed for any candidate rather than trusting a "community" label.

Juveniles are gregarious, but adults form monogamous pairs and each pair claims a territory a couple of feet across when breeding, laying eggs on a flat stone, wood, a broad leaf or the glass. Do not buy a group of youngsters for a modest tank assuming they will stay a peaceful crowd: be ready to separate pairs as they form, and decide in advance what happens to eggs or fry if a pair spawns in a community.

Feed the slow picker, not the fastest mouth

This is an unfussy but deliberate feeder that picks food carefully rather than snatching it. Seriously Fish recommends quality dried foods as the staple, varied with live or frozen bloodworm, brine shrimp and daphnia for condition; FishBase records worms, crustaceans and insects as natural prey. Offer some food that sinks or reaches the lower water where it feeds.

Follow the food's directions, watch what the keyhole cichlid itself swallows, and remove what is left. In a shared tank, food disappearing quickly may mean faster fish ate all of it; if so, change where food is delivered or reconsider the companions rather than simply increasing the ration. A sustained drop in intake is information to investigate, not a cue to pile in extra meals.