Conversely they should be watch for signs of injury if placed into a tank with aggressive fishes. These fish should be either solitary, or placed into a tank in groups of three or more. If two fish are placed together one will usually pick on the other. This family includes only two species of Pinecone fish. These exotic expensive specimen fish are in the realm of the specialists fish.
Pinecone fish have a bioluminescent organ under their eye that they use to signal one another.
To thrive they need a tall aquarium with subdued lighting and tranquil tankmates. They eat live fishes and shrimp at first and can be trained to eat prepared foods. Rarely seen, but non the less very impressive, they are well worth the effort. Their care is similar to Pinecone Fish and tend to be a little more tolerant of light and tankmates. Cardinal fishes are in many respects the damsel fishes of the night.