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
A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.
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
Owner questions the things everyone asks
How often should I feed my Pajama Cardinalfish?
Feed small amounts once or twice a day. Furry Diary's starting plan is to offer food daily, and it is best to give only what they can eat in a couple of minutes.3 Furry Diary plan
What does a Pajama Cardinalfish eat, and what should it never eat?
They are carnivores and enjoy meaty foods like mysis shrimp, chopped seafood, bloodworms, and quality pellets or flakes. Never feed them anything that is not meant for marine fish, and avoid overfeeding.3
How much space does a Pajama Cardinalfish need?
A minimum of 20 US gallons (76 L) is needed for one, and 30 US gallons (114 L) or more is recommended for a small group. They also need plenty of hiding places among rockwork or branching shelter.3
What temperature, light or water does a Pajama Cardinalfish need?
They need saltwater at 22 to 26 °C (72 to 78 °F), with a pH of 8.1 to 8.4, dKH of 8 to 12, and specific gravity of 1.020 to 1.025. Furry Diary's plan includes daily temperature checks and weekly salinity checks.3 Furry Diary plan
How often should I clean a Pajama Cardinalfish's home?
Furry Diary's starting plan suggests cleaning the glass weekly and doing a 10 to 20% water change every two weeks. Regular water testing each week helps keep conditions stable. Furry Diary plan
Can a Pajama Cardinalfish live with others?
Yes, they are social and do well in small groups with peaceful tankmates. Pairs often stay together over several breeding cycles, and they settle into a pecking order without fighting.123
How long does a Pajama Cardinalfish live?
Their lifespan varies depending on care and environment. For specific details, it is best to ask a good breeder or an exotic-pet vet.
Can I handle a Pajama Cardinalfish?
It is not recommended to handle them, as they are delicate fish that can be stressed by physical contact. Enjoy watching them hover among the shelter and become active at dusk.13
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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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
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.