Blue-eyed Cardinalfish shelter in daylight

Blue-eyed Cardinalfish shelter among branching corals during the day. They often gather in small groups close to the coral. At night, they leave their shelter to feed.

Identifying the Blue-eyed Cardinalfish

The Blue-eyed Cardinalfish gets its common name from the bright blue color around its eyes. Its scientific name is Ostorhinchus compressus. The body is pale, with several narrow red-brown stripes running along the sides. The tail also has dark markings near its base.

The body is slender and compressed from side to side. Like other cardinalfish, it has large eyes. The large eyes help the fish see in low light. Adults can reach about 12 centimeters in length, but most are smaller.

Sheltering in Gorontalo’s hard corals

Blue-eyed Cardinalfish are usually found close to branching corals. They may gather around coral colonies or hide among the branches. During daylight hours, they remain close to their shelter.

A group may hover quietly among the coral branches. They can be difficult to see because their pale bodies blend with the reef. A diver who moves slowly may see them before they disappear into the coral.

When approached, the group usually moves deeper into the coral for protection. The fish swim in headfirst, making themselves difficult to see. In our video, the Blue-eyed Cardinalfish stay in a depression between branching coral colonies. As a result, they are entirely visible. Watch the largest fish chase smaller ones. Blue-eyed Cardinalfish also have a distinctive stop-and-go swimming pattern, seen clearly in our video.

Behavior & Feeding

The Blue-eyed Cardinalfish is mainly active at night. After dark, individuals leave the coral and search for small food in the water. They feed mainly on tiny crustaceans and other small animals in the water.

Like other cardinalfish, this species is a mouth brooder. After spawning, the male carries the eggs in his mouth until they hatch. This is an unusual and interesting behavior among reef fishes.

The Blue-eyed Cardinalfish is found in the tropical Indo-West Pacific. It occurs from Southeast Asia eastward to Papua New Guinea and the Solomon Islands. It is usually found on or near coral reefs in relatively shallow water.

This species is common in Gorontalo’s rich coral reefs. However, divers who wish to see this beautiful fish that likes to hide, please let your dive master know. For bookings, please contact us.