TankBud

Pajama cardinalfish

Sphaeramia nematoptera

Also known as Pyjama Cardinalfish, Spotted Cardinalfish, Coral Cardinalfish

SaltwaterFish

Pajama cardinalfish (Sphaeramia nematoptera)
Brian Gratwicke · CC BY 2.0

Care at a glance

Temperature
72–81°F
22–27°C
pH
8.1–8.4
Adult size
3.1 in
8 cm
Minimum tank
29 gal
110 L
Temperament
Peaceful
Social behavior
Social
Swim level
Middle
Difficulty
Easy
Breeding
Medium
Rarity
Very common
Reef safe
Reef safe
Family
Apogonidae
Origin
Indo-West Pacific (Java to Fiji, north to Ryukyu Islands)

Overview

Pajama cardinalfish are reef safe and leave corals and clams alone, but they are not fully invertebrate safe since they will eat very small ornamental shrimp that fit in their mouths. They are among the more peaceful marine fish and do well as a pair or a small group, though individuals can bicker or pair off and get pushy toward each other when breeding, so give a group room to spread out. Offer frequent small meaty feedings of mysis and enriched brine.

In the wild

Pajama cardinalfish live over sheltered lagoon reefs and among branching corals across the Indo-Pacific, where they hover in loose groups by day and become more active at dusk. In the aquarium they like a tank of at least 110 liters with rockwork or coral branches to hang beneath and open water in front of it. They are largely nocturnal feeders in the wild, so they appreciate cover during bright daylight and settle quickly into a calm community.

Good to know

The striking pattern (a green face, a bright orange band, and red polka dots on a pale rear body) breaks up the fish's outline against a busy reef backdrop. Like other cardinalfish it is a paternal mouthbrooder, the male incubating the fertilized eggs in his mouth for roughly one to four weeks before releasing well developed fry. Those fry still need tiny live foods such as rotifers and copepods, which is what makes rearing them harder than spawning them.

Did you know

A group of pajama cardinals will often stack up almost motionless under the same coral branch during the day, drifting together like they are all wearing matching pajamas, then spread out to hunt once the lights dim.

Weekly picks

Tank mates

Pajama cardinalfish is a peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a Pajama cardinalfish need?

A Pajama cardinalfish needs at least 29 gal (110 L). It spends most of its time in the middle.

What temperature and pH does a Pajama cardinalfish need?

A Pajama cardinalfish is comfortable at 72–81°F (22–27°C) with a pH of 8.1–8.4.

How big does a Pajama cardinalfish get?

An adult Pajama cardinalfish reaches about 3.1 in (8 cm).

Related species