The Yellow Cubicus, Ostracion cubicus, also known as the Cubicus Boxfish, Yellow Boxfish, Polka Dot Boxfish, or Cube Boxfish, This fish is one of the most unique marine fish species available. At the juvenile stage, they are easily identifiable as they have a yellow box-shaped body with brown spots. But in the  adult stage, the yellow will fade and become brown.  Their incredibly unique box-shaped body makes them a fun and entertaining fish to watch in your tank. However, the Yellow Cubicus is fickle and should only be cared for by expert and  experienced aquarists. They can reach a size of 15 inches, and should be kept in a tank no less than 100 gallons, with plenty of live rock and a sand substrate. It is a great reef fish as long as it is not kept with larger, more aggressive or speedy fish. Be sure not to house the Yellow Cubicus with cleaner type fish as well,  as it has sensitive skin, and they do secrete poison from skin glands when stressed or in danger. This poison may kill fish in the aquarium very quickly.  Also be sure to keep the lid on your tank tightly sealed to prevent jumping. The Yellow Cubicus can pick on smaller inverts and tubeworms once it gets larger so plan accordingly. The Yellow Cubicus should be fed an omnivore diet. When first introduced to the tank, the Yellow Cubicus prefers a diet of live Brine shrimp or Bloodworms. And when acclimated, their diet should include chopped Squid, Clams, Mussels, and herbivore preparations for variety. They will thrive in a temperature range of  72-78° F and a pH of 8.1-8.4.