Blue Spot Boxfish - Male (South Pacific)

Boxfish are typically available in a very small size, however their growth potential is spectacular. They require suitably large aquariums to give them enough room to swim comfortably. We recommend boxfish only be kept by very experienced aquarists. Because of the boxfish's lack of mobility they are prone to being nipped on by other fish, which could prove disastrous. Boxfish contain a toxin, pahutoxin, which may be released into the water when the fish is stressed. When concentrated, pahutoxin may cause a frothing effect in the water. Within the confines of the aquarium this toxin, which is invisible, may become concentrated enough to damage the gills of every other fish in the aquarium, potentially causing death. If not corrected in time it may also cause the death of every other animal in the aquarium. For this reason boxfish should never be kept with any fish who may bother them, including groupers, angelfish, damsels, and any fish who may chase or bite them.

If it is suspected the water is poisoned a large water change should be conducted immediately and fresh carbon added. Other fish should be removed to a separate aquarium with new water. Boxfish have some resistance to their own toxin, however it can still injure them and it is possible for microfauna in the aquarium to die, creating an ammonia spike. Sudden lighting changes or other surprises may also stress the fish enough to cause toxin release.

Boxfish are typically peaceful towards all other fish. They are very personable and can learn to feed from their owner’s fingers. They are omnivores which may feed on many types of sponges, tunicates, worms, bivalves, and corals. They feel most secure when they have a cave or two to hide in, as well as plenty of open space for swimming. Caves should be large enough that so the boxfish can swim in and out comfortably. Diet should include plenty of high quality meaty items, marine algae, Spirulina, half shell clams, krill and Mysis shrimp. Boxfish should be fed at least 3 times a day. Never feed floating food or the boxfish may ingest air and develop buoyancy issues.

A stunning beauty, the Blue Spot boxfish has incredible patterning and coloration. Males are deep yellow with white polka dots on their backs, and bright blue with yellow polka dots on their sides. Females are a rich dark coffee color with striking white polka dots. The Blue Spot is the most prone of all the boxfish to releasing its toxin, so should never be kept with aggressive tank mates. They may be kept singly or in pairs. It grows to 6.5 inches; we recommend an aquarium of at least 50 gallons for a single fish, larger for a pair.