''Apogon erythrinus'', also called Hawaiian ruby cardinalfish, is a marine fish species endemic to Hawaii. It belongs to the family

Apogonidae Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably ''Glossamia'') are found in fresh water. A h ...

and the subfamily Apogoninae.

Description

The Hawaiian ruby cardinalfish is a relatively small red fish with a somewhat transparent appearance. They can grow up to 1.57" (4 cm). They have a second dorsal fin spine that reaches at least to the base of the third ray of their second dorsal fin when depressed, and they have 14 pectoral fin rays. They live for about four months.

Distribution and habitat

The Hawaiian ruby cardinalfish is endemic to the

Hawaiian islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...

. These fish are very shy, nocturnal, and prefer to hide in and patrol along holes and crevices.

References

Fish of Hawaii Apogon {{Kurtiformes-stub