Reef Cornetfish: Long, Thin, and Nearly Invisible

The reef cornetfish takes 'long and skinny' to an extreme — a see-through, ruler-thin fish with a trailing whip-like filament off its tail. It glides over sand and reef, often almost invisible until it moves. Here's how to spot one snorkeling near Jacó, plus five fun facts.

Reef Cornetfish · Fistularia commersonii

How to spot the reef cornetfish near Jacó

Scan open water just above sand flats and reef edges for a faint, pencil-thin shape that seems to appear out of nowhere. The cornetfish is often silvery and semi-transparent, so it's easy to miss until it turns and catches the light. Look for the extra-long thread trailing from its tail.

5 fun facts about the reef cornetfish

• A tail with a whip. Its tail ends in a long, thin filament that trails behind it — a feature that instantly sets it apart from the similar trumpetfish.
• Built for near-invisibility. Its slim, often semi-transparent body makes it very hard to see, which helps it drift close to unsuspecting prey.
• A long-snouted hunter. Like its trumpetfish cousin, it sucks up small fish and shrimp through a long, tubular snout.
• A world traveler. This cornetfish is one of the most widespread reef fish on earth, found across the Indian and Pacific Oceans — including our coast.
• Surprisingly long. Despite its needle-thin body, a cornetfish can stretch over five feet from snout to tail-whip.

The reef cornetfish is just one of many characters down there. See the whole cast in our Snorkel Jaco fish directory, or read real guest photos and reviews on the Snorkel Jaco reviews.