Cardinalfish are relatively small yet quite stunning tropical fish ideal for the marine aquarium. Distinguished from other small and fancy fish by their large eyes, Cardinalfish tend to be nocturnal. A semi-schooling fish, it is best not to have more than one male in a tank as schools are best formed when all the fish are female. Males will become aggressive with one another and the dominant male will harass the other males to death. Cardinalfish are quite hardy and easy to care for, making them popular and ideal for novice aquarists. Somewhat shy, Cardinalfish may take a while to adapt to tank life, and during this time may need a little extra care to ensure that they are not being bullied away from the food. One trick to getting them quickly acclimated is to feed them live brine shrimp.

Sub-Species for Aquariums:

Pyjama – A stunning specimen, the Pyjama Cardinalfish can be divided into three unique portions of the body. The head is a yellow color, with a bright orange eye and yellow pectoral and dorsal fins. The middle has a dark black band wrapping around it, and the tail is white with brown spots, clear anal fins and tail. One of the more peaceful varieties, it is possible to have a school of up to 8 in a 150 gallon tank.

Banggai – A more formal variety, the Banggai seems to be dressed for a black-tie ball with its shimmering silver body, graceful black stripes, and pearlescent spots shimmering on fins and body. This fish is active during the day, unlike other Cardinalfish, and can be kept in slightly larger schools as long as they are all female.

Flamefish – Somewhat plain when placed in comparison to the Banggai or Pyjama, the Atlantic born Flamefish is a solid peach or coral bodied fish with big, dark eyes and two spots: one on its back and one at the base of the tail.


Cardinalfish are quite easy to care for. They have no special water requirements beyond those of a healthy reef tank, so water temperatures between 78-82˚F and pH around 8.3 are the norm. They are somewhat shy and will require some special attention to get them acclimated to an already inhabited tank. Because they are nocturnal, owners may want to consider getting special nighttime lighting. It is important that owners realize that a common Cardinalfish defense is to “play dead”. Be sure your fish is dead before you dispose of it as it may simply be frightened.


Cardinalfish are omnivores and require equal amounts of vegetation and protein to survive. Brine shrimp are a favorite and an ideal way to encourage your new Cardinalfish to eat while adapting to a new tank. Algae pellets, fresh or frozen crab and shrimp meat, and shredded lettuce or spinach are excellent foods to feed your Cardinalfish.

Size: 5 Inches
Freshwater/ Saltwater: Saltwater
Diet: Omnivore
Reef Compatibility: 7
Tank Mate Compatibility: 5
Lifespan: Up to 10 Years

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