The polka-dot 'pajama' cardinal — a peaceful, patterned reef resident.
Pajama Cardinalfish (Sphaeramia nematoptera) are about 3 inches (8 cm), with a silvery front, a black spot near the tail, and yellow-and-brown striped hindquarters that look like pajamas. They are peaceful, hardy reef fish that school loosely and ignore corals.
They are easier than banggais for beginners and do well in a small group. They are mostly nocturnal and appreciate dimmer light and cave cover.
Pajama Cardinalfish live about 3-5 years with good marine care. Stable water and a calm group support that span.
What do Pajama Cardinalfish eat?
They take frozen/live foods like mysis and brine shrimp and usually accept pellets. The mistake is only flake; offer meaty foods for condition and color.
Tank size and water parameters
A 30-gallon (115 L) tank suits a small group. Target 74-80°F (23-27°C), pH 8.1-8.4, specific gravity 1.020-1.025, ammonia/nitrite zero, nitrate under ~20 ppm. Provide rock cover and gentle light.
Common mistakes with Pajama Cardinalfish
Key errors: aggressive tank mates that stress a peaceful fish; too-small group; bright constant light without caves; and poor marine water quality.
Beginner mistakes to avoid
Aggressive tank mates — they are peaceful and easily bullied.
Too small a group — keep a small shoal for confidence.
No caves/dim light — they are shy, mostly nocturnal.
Poor marine water quality — keep parameters stable.
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