---
title: Yellow Boxfish (Ostracion cubicum)
scientific_name: Ostracion cubicum
common_name: Yellow Boxfish
taxon: Boxfishes
conservation_status: LC - Least Concern
published: 2023-12-28T19:54:26.943Z
updated: 2026-08-12T09:10:55.080Z
tags: Yellow Boxfish, Ostracion cubicum, Boxfishes, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/boxfishes/yellow-boxfish
---

# Yellow Boxfish (*Ostracion cubicum*)

## Quick facts

- **Group:** Boxfishes (*Ostraciidae*)
- **Size:** up to 45 cm
- **Depth:** 1-50 m
- **Diet:** Omnivore
- **Activity:** Diurnal
- **Rarity:** Common
- **Habitat:** Sheltered reef and rubble, often around coral heads
- **Reproduction:** Broadcast spawner, Gonochoric
- **Hazard:** Poisonous
- **Conservation status:** LC - Least Concern

## How to recognise it

- rigid box-shaped body with a squared cross-section, fins working like propellers
- juveniles bright yellow with black dots, adults duller with pale-centered spots
- no scales - a shell of fused plates with holes for the eyes, mouth and fins
- length up to 45 cm

A swimming cube. The body is a rigid shell of fused hexagonal plates with holes cut for the eyes, mouth, fins and tail, so nothing about the fish bends: it moves by sculling with small fins while the body stays perfectly still. Juveniles are bright yellow dice with black spots; adults grow to 45 cm (18 in) and fade to olive with pale-centered spots.

The armor is the trade. It cannot flex, cannot accelerate and cannot hide, and in exchange it is very hard to bite and nearly impossible to swallow. Boxfish spend their days hovering in the open where other fish of their size would not last an hour.

The backup is chemical. Stressed or dying, the skin releases ostracitoxin, a soapy compound that damages the gills of other fish and can kill everything in a confined volume - a well-known way to lose an entire aquarium overnight. In open water it does nothing to a diver.

Feeding is done by blowing. The fish directs a jet of water at the sand to uncover worms and small crustaceans, then picks them off - the same trick the cowfishes use, in a shape even less suited to chasing anything.

## Also known as

- **English:** Yellow Boxfish, Black-spotted Boxfish, bluespotted boxfish
- **Arabic:** Sandook Al-Bahar, Sunduq Al-Bahr
- **French:** Poisson-coffre jaune
- **Japanese:** ミナミハコフグ, Minamihakofugu
- **Russian:** Кузовок-кубик

## Scientific synonyms

- *Ostacion cubicus* Linnaeus, 1758
- *Ostracion argus* Rüppell, 1828
- *Ostracion cubicua* Linnaeus, 1758
- *Ostracion cubicus* Linnaeus, 1758
- *Ostracion tuberculatus* Linnaeus, 1758

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/boxfishes/yellow-boxfish)*
*Updated: August 12, 2026*