Yellow Boxfish Identification Guide

Key identification features

• Rigid, cube-shaped body encased in a bony, hexagonal-plated carapace
• Juveniles are bright yellow covered in evenly spaced black polka dots, making them highly recognizable
• Adults become duller olive, tan, or brownish with faint, less distinct spotting
• Adult fins often show a subtle blue tint
• Small mouth and tiny, independently fluttering fins producing a slow, hovering swim
• Reaches up to about 45 cm (18 in)

Common look-alikes

• Spotted boxfish (Ostracion meleagris) adult male: distinctly blue with orange-yellow spots, unlike the Yellow Boxfish's tan or olive adult tone.
• Other juvenile boxfish: generally show different spot density or a more orange base color rather than the Yellow Boxfish's clean bright yellow.

Where you'll see one

Widespread across the Indo-Pacific on coral reefs. Juveniles hide in sheltered lagoons and coral crevices where their bright color and spots break up their outline, while adults range more openly over reef slopes, rubble areas, and sandy patches, feeding on sponges, algae, and small invertebrates.