---
title: Bigeyes (Priacanthidae)
scientific_name: Priacanthidae
common_name: Bigeyes
rank: Family
published: 2024-11-19T18:41:51.573Z
updated: 2026-08-23T21:43:03.756Z
tags: Bigeyes, Priacanthidae, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/bigeyes
---

# Bigeyes (*Priacanthidae*)

## Quick facts

- **Rank:** Family
- **Scientific name:** Priacanthidae
- **Body shape:** Oval - Egg-shaped body, deeper than it is thick - damselfishes, surgeonfishes.
- **Species listed here:** 2

## How to recognise this group

- oval, deep, and compressed body
- conspicuously large eyes
- large, upward-angled mouth
- resting in caves or shaded ledges during the day

Put a torch into an overhang at night and two coals look back at you. A bigeye's eye takes up much of its head, and behind the retina sits a reflecting layer that sends back whatever light missed on the way in and gives it a second pass, the same device that makes a cat's eyes burn in headlights. It is an instrument for an animal that does its living in almost no light.

The mouth points up. It is hinged to open skyward, and that is where the hunting is done: a bigeye hangs beneath its prey and takes it against the last gray light coming down from the surface, because a fish looking up can still make out silhouettes long after a fish looking down sees nothing but black. Small crustaceans, small fish, anything that rises through the water column after dark.

By day it does nothing, and it does it alone. That is the difference between a bigeye and the sweepers that often share the same cave. Sweepers pack in by the hundred; bigeyes hang singly or a few scattered under a ledge, deep red and motionless, letting a diver come closer than seems reasonable before drifting a body length further back. The color is not fixed either. The pattern can run from solid red through blotched to pale silver while you are watching it.

The rest of the fish is armor. The scales are rough enough to feel like a file, and a spine sits on the rear edge of the cheek, which is what the name refers to: the genus means saw spine.

Two species are listed here. The crescent-tail bigeye is the one divers meet, and the two are told apart mainly by the shape of the tail, which is exactly as useful as it sounds on a fish sitting still in a hole.


## Species (2)

- [Crescent-tail Bigeye (Priacanthus hamrur)](https://redseacreatures.com/taxon/fishes/bony-fishes/bigeyes/crescent-tail-bigeye)
- [Peony Bigeye (Priacanthus blochii)](https://redseacreatures.com/taxon/fishes/bony-fishes/bigeyes/peony-bigeye)

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/bigeyes)*
*Updated: August 23, 2026*