Large-eyed fish that spend the day under a ledge, inside a sponge or among urchin spines, and feed in open water at night. Males brood the eggs in the mouth and do not feed while they are doing it.
The mouth-brooding is the reason to look at a cardinalfish's head. A male carrying eggs has a visibly distended jaw, and he airs the ball by spitting it out and taking it back, which is the moment worth waiting for. The eggs are large enough for the eyes to show through in the later stages.
The Banggai cardinalfish is the exception in almost every way. It has no larval stage that drifts, so the young settle where they hatch, and its natural range is a few islands. Populations elsewhere are from the aquarium trade.
Many live with something else: among the spines of a long-spined urchin, inside a barrel sponge, or over one coral head that a group returns to every day. Several of the isopods on the site are found on a cardinalfish's flank.
Every one has a page. They are shown as a list rather than as pictures because nothing has been photographed or logged for them yet, and a species with nothing behind it should not sit in front of one that has.
How many of the 13 carry a record at each destination. A species usually carries several, so these do not add up to 13.
All 1316 species in one index, with filters for destination, rarity and hazard.
