As the name suggests, the boxfish is box-shaped, growing to a maximum length of 45 cms (18 in). It dwells on coral reefs throughout the Pacific Ocean, southeastern Atlantic Ocean, and Indian Ocean, feeding mostly on a diet of algae, sponges, worms, molluscs and crustacea. Whilst a juvenile the boxfish is bright yellow, with the colour fading to blue-grey when older. The colouration warns a potential predator to keep its distance, as the boxfish excretes a potentially lethal poison from its skin when injured or stressed. Although awkward in shape, the boxfish moves with incredible agility, aerodynamically bobbing in all directions thanks to tiny specialised fins. Because of its unique look, the boxfish is a favoured aquarium pet. It is regularly removed from the wild and shipped worldwide for the pet-shop trade.