Not furry, but we like them anyway.
Pajama Cardinalfish
Sphaeramia nematoptera
Also called Pyjama cardinalfish, Spotted cardinalfish, Coral cardinalfish, Polkadot cardinalfish
From Indo-Pacific, from Java east to Fiji, north to the Ryukyu Islands and south to the Great Barrier Reef1
At a glance the quick version
Looks how to spot one
Chunky, big-eyed cardinalfish
A rounded fish dressed like it is ready for bed: a greenish-yellow face, big orange-red eyes, a broad dark band across the middle and a silvery rear half covered in orange-red polka dots.23
Personality what they are like
Gentle and easygoing. Groups settle into a pecking order without fighting, which makes them a relaxed addition to a community reef.32
Daily activity how busy a day looks
Fairly quiet by day, hovering among branches and shelter, and more active around dusk and at night when it heads out to feed.13
Grooming and care the hands-on bits
Offer rockwork or branching shelter to hover in and feed meaty foods once or twice a day.3
Home where they are happiest
Minimum about 20 US gallons (76 L), with 30 US gallons (114 L) or more for a small group, and plenty of hiding places. Saltwater at about 22 to 26 °C (72 to 78 °F), pH 8.1 to 8.4, dKH 8 to 12, specific gravity 1.020 to 1.025.3
Food basics what goes in the bowl
Carnivore. Offer meaty foods such as mysis and other frozen shrimp, chopped seafood, bloodworms and quality pellets or flakes.3
Company who they like around
Social: wild fish gather in groups among coral branches, and in the aquarium they do well in small groups with peaceful tankmates. Pairs often stay together over several breeding cycles.123
The story where it all began
Pieter Bleeker described the species in 1856. Its common name comes from its colour pattern, which looks a lot like a set of spotted pyjamas.2
Fun facts for the dinner table
- 1
Fathers carry the fertilised eggs in their mouths for roughly 8 to 31 days.2
- 2
Pairs are socially monogamous and often stay together for several rounds of breeding.2
- 3
By day it rests among coral branches and by night it spreads out to feed near the bottom.1
- 4
It has been bred successfully in captivity.1
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 2021)1
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Pajama Cardinalfish. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Salinity checkevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water testevery week
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Glass cleanevery week
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- FishBase: Sphaeramia nematoptera summary fishbase.seused for origin, size, habitat, behaviour, IUCN
- Wikipedia: Sphaeramia nematoptera en.wikipedia.orgused for history, other names, colour, reproduction, temperament
- LiveAquaria: Pajama Cardinalfish liveaquaria.comused for care, water parameters, tank size, diet, colour
Checked 2026-09-30. Text is written in our own words from these sources.