Pajama Cardinal Fish Care Guide

Scientific Names: Sphaeramia nematoptera
Origin: Indo-Pacific
Adult Size: 31/2”
Difficulty Level: Easy
Diet: Carnivorous
Min. Tank Size: 20 gallons
Compatibility: Peaceful with other species
Reef Safe: Yes

Pajama Cardinals are colorful, peaceful and affordable, making them perfect for beginners and advanced aquarists alike. They usually live in groups in nature but can be kept individually in the aquarium. Dominance hierarchies can develop in groups, so a larger aquarium with plenty of cover is best if you decide to go that route. They are peaceful towards other tank mates but frequently are not fully grown when offered for sale, so expect some growth over time. They are paternal mouthbrooders, meaning the male incubates the eggs in his mouth, and have been known to breed in captivity. They are sometimes reluctant to eat dry foods at first, so you may have to coax them with brine shrimp or other frozen foods, weaning them to pellet and flake foods later. They are nocturnal in the wild, so if you have one that won’t eat, try feeding them at night. As carnivores they do best on a varied meat-based diet.


Temperature: 74°- 80° F
Specific Gravity: 1.020 – 1.025
pH: 8.0 – 8.4
KH: 8° - 12°
Nitrate: < 10 ppm
Regardless of your experience level, always research any animal before purchasing.