Cubicus Boxfish (Ostracion cubicus)

Max Size: 1 foot 6 inches
Diet: Omnivore
Temperament: Semi-Aggressive
Reef Compatible: With Caution. May eat tubeworms
Minimum Tank Size: 200 gallons

The Cubicus Boxfish, also known as the Yellow Boxfish, Polka Dot Boxfish, or Cube Boxfish, displays distinct appearances in its juvenile and adult stages. Juvenile Cubicus Boxfish feature a vibrant yellow, box-shaped body adorned with brown spots. As they mature into adults, the yellow hue gradually gives way to a brown coloration. It is worth noting that the Cubicus Boxfish can sometimes be mistaken for the Longhorn Cowfish, which is also occasionally referred to as the Yellow Boxfish.

Keeping the Cubicus Boxfish in an aquarium setting is a challenging endeavor, suitable only for experienced aquarists. Providing a tank with a minimum capacity of 125 gallons is essential for their well-being. If placed in a reef tank, caution should be exercised as they have a tendency to nibble at tubeworms. When stressed, the Cubicus Boxfish secretes a toxic substance called ostracitoxin from its mucous glands, which can swiftly prove fatal to other tank inhabitants.

Breeding the Cubicus Boxfish in an aquarium setting has been met with very limited success.

When introducing the Cubicus Boxfish to the aquarium, their diet should primarily consist of live brine shrimp or bloodworms. Once acclimated, their diet can be diversified to include chopped squid, clams, mussels, and herbivore preparations.

Due to their unique and intricate nature, the Cubicus Boxfish serves as a captivating addition to the aquarium. However, their care demands extensive knowledge and careful consideration of tank mates to ensure a successful and harmonious aquatic environment.