Saltwater Fish
Pajama Cardinalfish.
A charming, slow-moving cardinalfish in mismatched 'pajama' patterns — yellow face, dark band, and polka-dot tail. Peaceful, reef-safe, and beginner-friendly; it's happiest in a small group hovering among the rockwork of a 30-gallon-plus reef.
We keep this species at our Erie store. Come and see it in the tanks, or call (814) 456-9445 and ask what we have in right now.
Sea Cave keeps this species. You will find these in the tanks at 660 East 14th Street in Erie. We never ship live animals.
- Condition
- new
- Fulfillment
- Local pickup — Erie, PA
We never ship fish, coral, or invertebrates — every animal here is one you meet in person. Each one is acclimated and health-checked in-house before it goes out into the display tanks. This is a species we keep, and what is swimming on any given day changes with the deliveries, so please call (814) 456-9445 before you drive in.
Care at a glance
What to know before you take one home.
- Care level
- Beginner
- Temperament
- Peaceful
- Community
- Community safe
- Adult size
- 3.5"
- Min tank size
- 30 gallons
- Diet
- Carnivore
- Scientific name
- Sphaeramia nematoptera
Good tank mates
The pajama cardinalfish is peaceful, reef-safe, and community-friendly, making it a calm pick alongside clownfish, firefish, gobies, and other non-aggressive reef fish. It is happiest kept in a small group and won't bother corals or most invertebrates, though it may eat very tiny ornamental shrimp; avoid housing it with aggressive or fast fish that will stress this slow-moving species. It schools loosely and adds quiet movement to a peaceful tank.
Good to know
Like other cardinalfish, the pajama cardinal is a paternal mouthbrooder, with the male holding and protecting the fertilized eggs inside his mouth until they hatch.
What is in the tanks and each animal's temperament vary — call (814) 456-9445 for pairing advice.
Good tankmates
Plays well with.
Species we’d keep in the same tank, with why each pairing works. What is in the tanks and each animal’s temperament vary — call (814) 456-9445 for advice on pairing.
New to stocking a tank? Read our guide on which fish live together.
Ultra Black Ice
Well-documented, high-confidence pairing. Both species are small (Cardinal ~3 in, Clownfish up to ~4.3 in), peaceful, reef-safe, and mid-water community fish with no predation risk in either direction. A marine compatibility guide gives them a perfect compatibility score. Neither species is fast or aggressive enough to outcompete the other at feeding.
Royal Gramma
Fully compatible with proper setup. The Royal Gramma defends a cave territory on the rockwork and rarely wanders into the open water the Pajama Cardinal occupies. One documented anecdote describes brief initial chasing of cardinals that resolved once the gramma recognized they were not competing for its cave. Compatible in tanks 30+ gallons with adequate rockwork. Multiple sources list cardinalfish as recommended Royal Gramma tankmates.
Firefish Goby
Peaceful, non-competing pairing. Firefish occupy a lower vertical zone near rockwork burrow entrances while Pajama Cardinals hover mid-water; the two species ignore each other. Pajama Cardinals are not fin-nippers or chasers, so they will not trigger the Firefish's well-known stress-jumping behavior. Both species are commonly cited together as ideal peaceful community reef fish.
Yellow Watchman Goby
Zero territorial overlap. The Yellow Watchman spends virtually all its time at the substrate level in or near its burrow, while the Pajama Cardinal is a mid-water swimmer. The goby's documented aggression is limited to conspecifics competing for the same burrow. Multiple sources list gobies and blennies alongside cardinalfish as ideal community reef tank companions.
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Neon Goby
Directly endorsed pairing from multiple sources, including one that explicitly names neon gobies as among the best tankmates for Pajama Cardinalfish. Although the size difference is notable (Neon Goby ~0.8 in vs. Cardinal ~3 in), cardinalfish are not ambush predators of free-swimming fish, and neon gobies are universally kept successfully alongside them. Both are peaceful, reef-safe, and occupy different micro-zones.
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Tailspot Blenny
A well-matched, peaceful pairing. The Tailspot Blenny grazes algae from rockwork surfaces and stays low in the tank, never competing with the cardinalfish's mid-water territory. Compatibility lists for both species overlap without conflict, and cardinalfish are explicitly named as compatible tankmates for Ecsenius blennies. The only documented caveat for the Tailspot Blenny is occasional individual-level SPS (small-polyp stony) coral nipping, which is irrelevant to fish-to-fish compatibility.
Visit the store
660 East 14th Street,
Erie, PA.
Mon–Fri 12–6 · Sat 11–4 · Sun closed. Call ahead on livestock — what's on the floor rotates.