How to Identify Bluespotted Cornetfish

To identify Bluespotted Cornetfish (Fistularia commersonii), look at these key features.

Physical Characteristics

Body shape

eel-like

Coloration

Typically greenish-brown to reddish-brown dorsally, fading to silvery-white ventrally. Distinctive bright blue spots or lines are often present along the back and sides, particularly when excited or during courtship. Can rapidly change coloration to blend with its surroundings.

Scale type

none

Mouth position

terminal

Distinctive features

Extremely elongated, cylindrical body, often reaching up to 160 cm (63 inches) in total length, though more commonly 60-100 cm., Very long, tubular snout with a small, terminal mouth., A prominent, whip-like filamentous caudal fin ray, which can be as long as the rest of the body., Absence of scales on the body, giving it a smooth appearance., Lateral line is well-developed and runs along the side of the body.

Dorsal fin

Single dorsal fin, located far back on the body, opposite and similar in shape to the anal fin. Typically has 14-17 soft rays.

Tail fin

Forked caudal fin with a greatly elongated, filamentous central ray.

Pectoral fin

Small, fan-like pectoral fins located just behind the operculum, with 15-17 rays.

Distinctive fins

Pelvic fins are small and abdominal, located well behind the pectoral fins. Anal fin is similar to the dorsal fin in size and ray count (14-17 soft rays).

Identification Tips

1. 1

   Body Shape and Snout

   Look for the extremely long, slender, and cylindrical body combined with a very long, tubular snout. This is a key characteristic of all cornetfish.

2. 2

   Caudal Fin Filament

   The most distinctive feature is the whip-like, elongated central ray of the caudal fin. This filament can be as long as the rest of the fish's body.

3. 3

   Coloration and Spots

   Observe for the presence of bright blue spots or lines along the back and sides, especially when the fish is active or displaying. While not always prominent, these spots are a good indicator for F. commersonii.

4. 4

   Absence of Scales

   Note the smooth, scaleless body, which differentiates it from some other elongated fish species.

5. 5

   Behavior

   Its characteristic hunting style of hovering motionless, often head-down, or slowly drifting among cover, is a strong behavioral identifier.

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