The yellow boxfish is an interesting but challenging fish to keep in the marine aquarium. While cute as juveniles, the yellow boxfish can grow up to 18 inches so a very large aquarium is required to house this species. The yellow boxfish is not aggressive toward non-related species but can be aggressive toward like species. If you are going to keep two, consider two females. The yellow boxfish should be kept with other passive fish. This will reduce the level of stress in the boxfish and limit the chance that it emits the ostracitoxin that can kill everything in the tank, including itself. Consider a species tank for the yellow boxfish if you are concerned about your current collection of fish, and especially if you keep expensive specimens.
Fish to avoid housing the boxfish with include moray eels, big dottybacks, snappers, aggressive angelfish, big damsels, surgeonfish, triggerfish and puffers.
Yellow boxfish eat a variety of fish foods. Feed it meaty foods such as krill, table shrimp, squid, clams, and other shellfish as well as algae-based foods. They are not aggressive eaters, and if the tank in which it is housed has aggressive feeding fish, it won't get enough to eat. If your boxfish is finicky about eating, add some live rock that has invertebrates and algae attached to it. If this is not available, you can smash frozen prepared foods onto a piece of dead stony coral and the yellow boxfish should be able to find and eat the food.
Click here to watch a video of the yellow boxfish.