Yellow Boxfish

The Yellow Boxfish is iconic in the hobby, especially in its juvenile stage where it is a bright, neon yellow cube with perfectly circular black spots. As they mature, the yellow fades into a more mustard-to-greyish tone, and the spots become smaller or white-centered, while the body becomes more elongated. They are slow swimmers that prefer calm areas of the tank. While they are peaceful and full of personality, they can grow quite large and become a major bio-load on the system. They are inquisitive and will investigate everything in the tank with their puckered mouths, often nipping at tube worms and small invertebrates.