Spotted Boxfish Identification Guide
Tell males from females of this reef boxfish by their strikingly different blue-and-orange versus dark-and-white patterns.
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Key identification features
- Rigid, box-shaped body encased in a bony carapace, typical of boxfish
- Males: dark blue body with a network of orange-yellow spots concentrated on the upper back and sides
- Females: dark brown to black body covered in small, evenly spaced white spots
- Small mouth and independently fluttering fins producing a slow, hovering swim
- Angular, hexagonal cross-section visible when viewed head-on
- Reaches up to about 25 cm (10 in)
Common look-alikes
- Yellow boxfish (Ostracion cubicus) adult: tan to olive with faint spotting, lacking the Spotted Boxfish male's vivid blue coloration or the female's crisp white spots on black.
- Whitespotted pufferfish species: soft-bodied and inflatable, easily distinguished from the Spotted Boxfish's rigid, angular carapace and boxy outline.
Where you'll see one
Found throughout the Indo-Pacific on coral reefs, favoring exposed reef faces, rubble zones, and areas with mixed coral and rock. Males and females are often seen separately, and their strong color difference can make them look like two entirely different species to inexperienced divers.
Frequently asked questions
How do I tell a male from a female Spotted Boxfish?
Males are dark blue with orange-yellow spots on the back, while females are dark brown to black with small, even white spots covering the body.
How do I distinguish this species from a Yellow Boxfish?
The Spotted Boxfish shows strong blue or black-and-white coloring depending on sex, while the Yellow Boxfish is tan to olive without that bold contrast.