How big does Pajama Cardinalfish get?

Pajama Cardinalfish reaches an adult standard length of 7–9 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.

What water does Pajama Cardinalfish need?

24–27 °C, pH 8.1–8.4, 7–12 dGH, 7–9 dKH, specific gravity 1.023–1.026. That is only 3 °C wide, so stability matters more than hitting a particular number.

What is the smallest tank for Pajama Cardinalfish?

At least 100 L, and no shorter than 80 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is not a schooling fish, so a single specimen or a pair is fine.

What is Pajama Cardinalfish like to keep?

Temperament: peaceful. Difficulty: beginner. It occupies the middle and is carnivore. Reef safety is "Reef safe".

Can Pajama Cardinalfish be kept with its most common tank mate?

The checker returns "Can be kept together". Pajama Cardinalfish and Ocellaris Clownfish is a well-established pairing. Individual fish still differ; the record says "usually fine", not "guaranteed".

G-01 / 64Marine

Pajama Cardinalfish睡衣天竺鲷

Sphaeramia nematoptera · Apogonidae

Yellow front, spotted rear; a hardy nocturnal cardinalfish that hovers in groups.

Illustration to come

G-01 / 64 · Pajama Cardinalfish Sphaeramia nematoptera

SpecificationsFish atlas

Name: 睡衣天竺鲷
Scientific name: Sphaeramia nematoptera
Family: Apogonidae
Origin: Western Pacific coral reefs
Adult size: 7–9 cm
Temperament: Peaceful
Diet: Carnivore
Water level: Middle
Level: Beginner
Min. tank: 100 L
Min. length: 80 cm
Reef safe: Reef safe

Water requirementsMarine

Temp.24–27 °C

pH8.1–8.4

Salinity1.023–1.026 SG

Alkalinity7–9 dKH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Keeping notes

1Shelters by day and becomes active at dusk; feed around lights-out.
2Does better in groups of five or more with stable spacing.
3Carnivore taking frozen mysis, brine and pellets.
4Reef safe and harmless to tankmates; a good filler fish for a reef tank.
5Swallowed whole by large predators; avoid lionfish and morays.

Check a tank mate

Jump straight to the verdict for Pajama Cardinalfish against this one — no need to pick it again.

Frequently asked questions

How big does Pajama Cardinalfish get?: Pajama Cardinalfish reaches an adult standard length of 7–9 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.
What water does Pajama Cardinalfish need?: 24–27 °C, pH 8.1–8.4, 7–12 dGH, 7–9 dKH, specific gravity 1.023–1.026. That is only 3 °C wide, so stability matters more than hitting a particular number.
What is the smallest tank for Pajama Cardinalfish?: At least 100 L, and no shorter than 80 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is not a schooling fish, so a single specimen or a pair is fine.
What is Pajama Cardinalfish like to keep?: Temperament: peaceful. Difficulty: beginner. It occupies the middle and is carnivore. Reef safety is "Reef safe".
Can Pajama Cardinalfish be kept with its most common tank mate?: The checker returns "Can be kept together". Pajama Cardinalfish and Ocellaris Clownfish is a well-established pairing. Individual fish still differ; the record says "usually fine", not "guaranteed".