Pajama Cardinal

Pajama Cardinal Overview

• Common Name: Pajama Cardinalfish

• Scientific Name: Sphaeramia nematoptera

• Family: Apogonidae (Cardinalfishes)

• Origin: Western Pacific – including Indonesia, Papua New Guinea, and the Great Barrier Reef

• Size: Up to 3 inches (7.5 cm)

• Lifespan: 5–6 years (in a well-maintained aquarium)

🌈 Appearance

• Body: Oval-shaped, tall and compressed

• Color Pattern:

  • Greenish-yellow face and front half

  • Bright red eyes

  • Distinct black vertical band mid-body (like a "belt")

  • Rear half is silver with red/orange polka dots (hence the “pajama” look)

• Sex Differences: Not easily distinguishable; females may be rounder when breeding

🏝️ Natural Habitat

• Found in calm lagoons and reef edges

• Often hide among branching corals, seagrass, or under ledges during the day

• Nocturnal tendencies – more active at dusk and night

🐠 Aquarium Care

Tank Requirements:

• Minimum Tank Size: 30 gallons (114 liters) for a small group

• Best Setup:

  • Plenty of live rock for hiding

  • Open swimming space

  • Dim or moderate lighting (bright lights can stress them)

• Reef Safe: Yes – won't bother corals or inverts

Water Parameters:

• Temperature: 72–78°F (22–26°C)

• pH: 8.1–8.4

• Salinity: 1.020–1.025 SG

• Ammonia/Nitrites: 0 ppm

• Nitrates: <20 ppm preferred

🤝 Behavior & Compatibility

• Temperament: Very peaceful and calm

• Schooling: Best kept in small groups (3–6). Single individuals may become shy or stressed. Avoid odd numbers in small tanks due to pecking order aggression.

• Tankmates: Ideal for community reef tanks. Avoid large, aggressive fish like lionfish or triggers.

🍽️ Diet

• Feeding Type: Carnivore

• Diet:

  • Frozen mysis and brine shrimp

  • Finely chopped seafood

  • Enriched live foods (occasional)

  • High-quality marine pellets/flakes

• Feed 1–2 times daily. They are slow eaters, so ensure they aren’t outcompeted.

✅ Pros

• Reef safe

• Peaceful community fish

• Easy to care for

• Adaptable to a wide range of setups

• Can be tank-bred, making them hardier and more sustainable

❌ Cons

• Can be bullied by aggressive tankmates

• May show minor aggression in small groups (hierarchy)

• Easily stressed by sudden lighting or loud movement

💡 Breeding

• Known to mouthbrood – males carry eggs in their mouth

• Breeding possible in captivity, especially with stable pairs

• Requires a separate rearing tank for fry due to predation

Summary