Pajama Cardinalfish

Updated August 6, 2019
Author: Mike - FishLore Admin
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The Pajama Cardinalfish is one of the most unique looking of all fish species. Why exactly do Pajama Cardinalfish have a solid vertical black bar mid-body with the red polka dots on a white body that looks like pajama bottoms?

Sphaeramia nematoptera Sphaeramia nematoptera

It's surely their way of adapting to their environment, but what in the world... A study of their pattern/coloration would be interesting to read.

The Pajama Cardinalfish is favorite with nano reef tank hobbyists due to their small size and temperament. They should get along with most other species (don't keep them with tank mates large enough to scarf them) and will leave the saltwater invertebrates in the tank alone.

Pajama Cardinal Fish get to be about 3 inches (8 cm) in size and should do well in at least a 30 gallon tank or larger. You can keep them in groups but watch for aggression amongst them as they grow and start to pair off for breeding. For the intrepid aquarists they are candidates for breeding in the home aquarium because they are a mouth brooder. The males get the mouth brooding duties.

Sphaeramia nematoptera Sphaeramia nematoptera

Feeding them can be slightly challenging at first. They may not go after flake foods and if that is the case try giving them defrosted or live brine shrimp or mysis shrimp. Try to get them on a good high quality flake food and feed them frequent small amounts of various foods to maintain health and vigor.

Overall, this is a fascinating little cardinalfish species that really grows on you. Check them out and if you get them to breed send us some pictures or post in the forum and tell others about it. The more Pajama Cardinal Fish tank raised specimens out there for hobbyists to purchase the better!

Sphaeramia nematoptera Sphaeramia nematoptera


Pajama Cardinalfish Care

Scientific Name : Sphaeramia nematoptera

Common Names : Pajama Cardinal Fish, Spotted Cardinalfish

Care Level : Easy to Moderate

Size : Up to 3 inches (8 cm)

Life span : 5 years, perhaps longer

pH : 8.1 - 8.4

Temperature : 72°F - 80°F

Specific Gravity : 1.023 - 1.025

Carbonate Hardness (dKH) : 8 - 12°

Origin / Habitat : Found throughout the Western Pacific, South to the Great Barrier Reef

Temperament / Behavior : You should be able to keep multiples in the same tank but watch them closely as they pair off and be ready to separate or remove the pairs because they can get somewhat aggressive with others when breeding. But, generally peaceful and will not bother tank mates.

Breeding : The Pajama Cardinal fish doesn't seem to be as popular for breeding as the Banggai Cardinal but they should be just as "easy". They are mouthbrooders like the Banggais. Getting a pair can be achieved by purchasing 4 to 6 pajamas and then letting them pair off as they grow into adulthood. It can take several months of feeding them high quality foods to get them ready to spawn. If you do get a successful spawn you'll want to be ready with enriched rotifers and after a week or so, live brine shrimp. These could be a good first fish to try and breed for those ambitious marine hobbyists out there.

Aquarium Size : 30 gallon (114 liters) minimum

Tank Mates : A favorite fish for reef tank setups because they are mostly peaceful with tank mates. You may see some bickering with conspecifics at times.

Reef Tank Compatible? : Yes, they should leave the invertabrates in the tank alone.

Fish Disease : Saltwater Fish Disease - Diagnose, Symptoms and Treatment - These cardinalfish are usually fairly rugged. Watch them closely at the fish store and skip any that are in a tank with other infected fish. Ask to see them eating before you buy them. Ask how long they've been in the tank and if it's been a couple of weeks and they look good, they should be fine for selection.

Diet / Foods : Mostly carnivorous, Pajama Cardinal Fish need frequent small feedings of meaty marine foods. Like other species a varied high quality diet will go a long way toward keeping them healthy and vibrant.

Tank Region : Seems to like to congregate in the middle levels near overhangs or crevices in the live rock.

Gender : It can be difficult to determine gender at the store. It should become easier as they mature to tell them apart. Males should become slightly larger and females should swell with eggs. The tell tale sign is when the males is mouthbrooding the fry.

Forum : Cardinalfish Forum

Photo Credit : Photos copyright

Site References :

Similar Species : Cardinalfish - Banggai Cardinalfish

Forum Avatar :
Pajama Cardinalfish

Pajama Cardinalfish Comments

From: Tim
I'm trying to breed Pajama Cardinal Fish right now. I bought 4 of them because that is all the store had. Hopefully they will pair off eventually... I do have another tank ready if I need to separate any of them. My plan is to get my hands wet breeding these pajama cardinals and if all goes well I'd like to start breeding the Banggai Cardinals too. I've already checked with the local shop and they'll give me about $5 a piece for any that reach about 1.5 inches in size. The breeding tank is a 29 gallon and I have about seven 10 gallon tanks available if I get a successful spawn and I'll get more tanks if I have to. Wish me luck!
This sounds awesome and we wish you the best in your efforts! Start practicing now on getting the foods ready for when you do eventually get some babies.