Bigeye Trevally: The Reef's Shimmering Silver Schools

A shimmering wall of silver fish wheeling together in the blue is one of snorkeling's most hypnotic sights — and the bigeye trevally is often the fish making it. Here's how to spot them near Jacó, plus five fun facts.

Bigeye Trevally · Caranx sexfasciatus

How to spot the bigeye trevally near Jacó

Look out toward open water, not just the rocks. Bigeye trevally gather in tight, slow-circling schools of dozens or more, their big eyes and deep silver bodies catching the light. They often hold in the same area by day, so once you find the school you can hover and watch it wheel.

5 fun facts about the bigeye trevally

• Named for those big eyes. The oversized eyes help them hunt in low light, which is when they do most of their feeding.
• They school by day, hunt by dusk. During the day they drift in lazy, tightly-packed schools; at dawn and dusk they break up to chase smaller fish.
• Found around the world. Bigeye trevally live across the Indo-Pacific and into the Eastern Pacific, making them one of the most widespread jacks.
• Those spinning schools have a purpose. Massing together confuses predators and makes it hard to single out any one fish.
• Fast and powerful. Like all jacks, they're built for speed, with a streamlined body and a stiff, crescent-shaped tail made for quick bursts.

The bigeye trevally 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.