Latin name

Monocentris japonica

Other name

Japanese pineapplefish

Identification

The body of the pineconefish has distinctly large, coarse scales. In appearance, it looks exactly like a pinecone. Its scales are very hard and provide good protection against predators. Vertebrae: 25–26. The eyes are large. The mouth is large, almost semi-inferior; the snout is rounded and noticeably protrudes forward in large specimens. In larger fish, the upper jaw extends well beyond the posterior margin of the eye; in smaller ones, it reaches the posterior edge of the orbit. The strong dorsal spines, when erected, point in different directions; the second spine is the longest; the sixth spine, if present, is very small.

These fish have light organs on each side of the lower jaw, filled with luminescent bacteria, the purpose of which is unknown—they may help the fish see at night or attract prey.

Features of fish fins

The dorsal fin has 5–6 rigid spines and 11–12 soft rays. The dorsal fin spines are rigid and not connected by membranes. The anal fin has 9–11 soft rays. The pelvic fins are large, with a locking mechanism.

Fish coloring

The body of the pineconefish is yellow, with black scale edges; the lower jaw is black.

Distribution

Widely distributed in the Indo-Pacific region, from the Red Sea and southern Africa to Indonesia, and from southern Japan to Australia and New Zealand.

Habitat

A marine tropical reef species. It inhabits depths from 10 to 200 meters (33 to 656 feet), both in rocky bottom areas and on coral reefs.

Behavior

Active at night, hiding during the day in caves and under ledges. Forms schools.

Size

Body length of these fish reaches up to 17 cm (6.7 inches), but they are more commonly found at 12 cm (4.7 inches).

Food and feeding habits

A carnivorous fish species.

Reproduction

They are livebearers and can reproduce year-round.

Fishing

This species is not commercially important.

Relationship with a person

Harmless. These fish are often kept in aquariums because they are not aggressive and are easy to care for.