- Species name: Sphaeramia Nematoptera
- Common names: Pajama, coral or Spotted Cardinalfish
- Family: Apogonidae
- Subfamily: Apogoninae
- Order: Perciformes (perch-likes)
- Class: Actinopterygii (ray-finned fishes)
- Maximum Length: 3.3 in.
- Minimum tank size: 30 gallons. Its size makes it perfect for large and for small aquariums.
- Hardiness: Easy. They handle transportation well.
- Aggressiveness: Peaceful. will not bother tankmates or each other.
- Reef Compatibility: Excellent
- Diet: Carnivore. Wild pajama cardinals feed on small crustaceans at night.
In the wild, the Pajama Cardinal lives on the reefs of the Western Pacific region (northeastern Australia, Papua New Guinea, and the Philippines) at depth of 3 – 45 m and is commonly found in small schools in amongst the branches of various types of branching Corals.
It has a silver coloration with a black vertical line in the middle and brown dots covering the rear portion of the body.
They can be feed with feeder shrimp, marine flesh, frozen meaty food, mysis and brine shrimp. Small ornamental shrimp may be looked on as food by larger cardinals. They prefer to feed at night and are not always willing to accept food during the daytime.
These nocturnal fish prefer to hide under ledges or in crevices during the day. With appropriate hiding places and absence of predators, it will become more active during daytime. It tends to hide in sea grass or other plants or may use long spine urchins for camouflage.
They do well in groups of at least five. As a group, they will establish a strict hierarchy without aggressiveness. The tank should be larger than 30 gallons to keep Pajama Cardinalfish in groups.
The ideal aquarium has a specific gravity ranging between 1.020 and 1.025. pH between 8.1 and 8.4 and temperature ranging between 72 and 78° F. with live rock, caves, and peaceful tank mates.