Bluespotted Cornetfish

Fistularia commersonii

Type: saltwater, reef fish

Bluespotted Cornetfish

Physical Characteristics

Extremely elongated, depressed body with a long, tubular snout terminating in a small mouth. Features two distinct blue stripes or rows of spots along the back. Dorsal and anal fins are set far back. It has a very long, whip-like filament extending from the center of the forked caudal fin.

Habitat & Distribution

Found in tropical and subtropical waters of the Indo-Pacific; has also migrated to the Mediterranean as a Lessepsian migrant. Typically inhabits coral and rocky reefs, seagrass beds, and sandy flats at depths from 1 to 130 meters.

Size & Weight

Commonly grows to 100 cm (3.3 feet), but can reach a maximum length of 160 cm (5.2 feet) including the tail filament. Weight is relatively light due to its slender profile.

Similar Looking Species

Red Cornetfish (Fistularia petimba), which is usually found in deeper water and lacks blue spots. Trumpetfish (Aulostomus chinensis), which has a thicker body, different fin placement, and lacks the long tail filament.

Ecological Role

An efficient mid-water and benthic predator that helps control populations of small fish and crustaceans. It often uses larger, herbivorous fish as mobile cover to sneak up on prey.

Diet

Carnivorous; feeds primarily on small fish, squids, and crustaceans. It uses its elongated snout like a vacuum to suck up prey with a rapid strike.

Behavior

Often solitary but can be found in small groups. They are known for 'shadowing' larger fish like groupers or parrotfish to hide from prey. They are primarily diurnal hunters.

Reproduction

Oviparous. They produce pelagic eggs that float in the open water. Larvae are also planktonic before settling into reef environments.

Conservation Status

Least Concern (IUCN). Populations are stable and they are widespread across their range.

Identification Tips

Look for a very long, thin, silver-grey body with a distinct whip-tail. While swimming, they appear stiff and stick-like. Note the blue spots or lines along the back which distinguish it from others in its genus.

Interesting Facts

The Bluespotted Cornetfish is a highly successful invasive species in the Mediterranean Sea. Its skeletal structure includes specialized vertebrae that allow for its incredibly long, rigid body shape.

Identified on: 6/7/2026

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