Crown Squirrelfish
Sargocentron diadema
Longspine Squirrelfish
Holocentrus rufus
About
Wedged into a dark crevice by day, the longspine squirrelfish waits for nightfall before it truly comes to life. Its huge eyes, built for low light, mark it out as one of the reef's most obvious nocturnal residents.
Also known as: wrenchman
How to tell it apart
About 150 species of squirrelfish share this same large-eyed, reef-dwelling look. This one is told apart by the long third spine of its anal fin, noticeably longer than the fin's other spines, which is also where its common name comes from.
Appearance
This fish has a silvery red body marked with orange-gold stripes, and, like all squirrelfish, unusually large eyes for its size. The rear part of the dorsal fin stands up prominently.
Habitat
It lives on coral reefs from the southeastern United States south to northern South America and Brazil, including Bermuda and the West Indies. It hides in and near dark crevices by day, and is uncommon on shallow reefs, becoming more common as depth increases. Juveniles are thin, silvery, and live out in open water, so they are rarely seen.
Did you know?
This squirrelfish makes two different sounds: a grunt to defend its territory, and a sharp staccato burst to warn of danger. When several fish staccato together in a behaviour called mobbing, they can drive off a predator as large as a moray eel.
Log it in Into the Blue
Describe what you saw and we name it, then keep every species you find in your Oceandex.
