Flame Cardinalfish (Apogon maculatus)

The Flame Cardinalfish (Apogon maculatus) brings glowing red color, bold dark markings and a little night-shift personality to the aquarium. Hardy and beginner friendly in an established marine tank, it spends much of the day near a favorite cave and becomes more active around dusk. Usually calm with suitably sized unrelated fish, it can be territorial with other cardinals.

Browse our saltwater fish and supplies to plan a comfortable home. Each purchase is for one fish.

Care Guide

• Tank size: 30 gallons or larger, with established filtration and room for separate territories.
• Aquascape: Include several caves, overhangs and shaded areas. A secure retreat helps this naturally dusk-active fish settle in.
• Feeding: Offer small portions of mysis shrimp, finely chopped marine seafood and other meaty foods two or three times daily. Try PE Saltwater Pellets for variety once it accepts pellets. Feed near its shelter if shy, and make sure faster fish do not take everything.
• Water parameters: 72 to 78°F, pH 8.1 to 8.4 and specific gravity 1.023 to 1.026. Keep ammonia and nitrite at zero and salinity stable.
• Lighting and flow: Provide shaded retreats and gentle to moderate circulation, with quiet areas away from direct pump outlets.
• Social needs: Keep one unless you have an established compatible pair and sufficient space. Avoid casually mixing cardinalfish species.
• Lid: A secure cover is recommended, especially while the fish settles in.

Specifications

Compatibility

Choose calm to moderately assertive marine fish too large to swallow, with enough space for each fish to claim shelter. Corals generally remain undisturbed, making this a possible choice for a thoughtfully stocked reef.

Small ornamental shrimp, tiny fish and some small worms can become prey. Avoid aggressive fish that keep it hidden or outcompete it at feeding time. Other cardinals may provoke territorial disputes. Our Pajama Cardinalfish is another option to consider for a different setup, rather than an automatic tank mate.

Recommended Foods & Supplies

• Marine fish foods, including frozen mysis and varied meaty blends.
• PE Saltwater Pellets 1 mm, 4 oz for variety once accepted.
• Water testing supplies to keep track of your marine aquarium.

FAQ

Is a Flame Cardinalfish reef safe?
It generally leaves corals alone, but may eat small shrimp, tiny fish and small worms. Choose its tank mates with that appetite in mind.

Can I keep two or mix different cardinals?
A single fish is the simplest choice. Unbonded Flame Cardinals and other cardinal species may fight. An established compatible pair needs adequate space and separate retreats.

Why does it hide during the day?
It is naturally most active around dusk and after dark. Daytime sheltering is normal, but persistent hiding can also indicate bullying. Make sure it has cover and gets enough food.

What size tank does it need?
Plan for at least 30 gallons with caves and shaded rockwork. Adults reach about 4 inches.

What does medium mean?
Medium is the supplier's size grade, not a guaranteed measurement or its adult size. Sold individually.