Care Level: Advanced

Temperament: Peaceful

Reef Compatible: With Caution

General Description: The Cubicus Boxfish, also referred to as the Yellow Boxfish, Polka Dot Boxfish, or simply Cubicus, is native to the Indo-Pacific. Typically offered at smaller sizes, juvenile Cubicus are yellow with many brown to black spots. As they mature, this yellow color becomes duller. Sometimes confused with the Longhorn Cowfish (Lactoria cornuta), however the cowfish possesses a pair of “horns” that distinguishes it from the Cubicus boxfish. While these fish can grow to an impressive 15″ in the wild, they stay significantly smaller in the home aquarium. Boxfish are often admired for their “puppy-like” behavior, in which they may eventually associate the hobbyist as their caretaker and therefore, will beg for food at the front of the aquarium. Exercise caution to not overfeed; select a feeding schedule that works best for you, your boxfish and aquarium as a whole.

Diet Requirements: In the wild Cubicus are omnivorous, feeding upon benthic algae, tubeworms, and various microorganisms. In the aquarium, Cubicus should be offered a variety of high quality frozen meaty foods, enriched shrimps, and foods containing algae such as Spirulina, Chlorella, and pieces of marine sheet algae for variety. It is not uncommon for Cubicus to ignore food upon introduction and that they can be extremely stubborn with accepting frozen foods at first. Offering live adult brine shrimp or black worms can help bridge the transition to frozen foods. We highly encourage soaking frozen foods in vitamin and fatty acid supplements for the boxfish’s health and to maintain body mass. Cubicus are slow eaters, and should not be housed with aggressive feeders that may out compete them in food resources. Note: Our Cubicus boxfish for sale are eating a combination of live foods and frozen foods, or frozen foods only. It is not uncommon for this species to revert back to only accepting live foods, or ignore food altogether, for a period of time due to the stress of a new environment.

Care Requirements: An established minimum 90 gallon aquarium is ideal to house a single Cubicus. While this size aquarium may seem like overkill for its size, it allows the Cubicus room to grow and to dissipate in greater volume any toxin that could be omitted by this fish. We highly suggest having carbon filtration on the aquarium as well to extract toxin from the water volume. Boxfish cannot tolerate nitrite or ammonia spikes and absolutely need generous live rock for feeding and some crevices to take refuge. Water movement should be on the gentle side because boxfish are not extremely powerful swimmers, and can easily be blown around. Cubicus may be housed together if all individuals are added at once. Do not house them with aggressive and extremely active tank-mates; a Cubicus would thrive best in a very timid and laid back fish only with live rock aquarium as they may nip certain sessile invertebrates in a reef aquarium. Recommended water conditions, 72-78° F, KH 8-12, pH 8.1-8.4, salinity 1.020-1.025

Purchase Size: Small: 2-1/4″ or less; Medium: 2-1/2″ to 3-1/4″

Note: Your item may not look identical to the image provided due to variation within species. Purchase sizes are approximate.

Caution: This species secretes or releases toxins when stressed or injured that may kill fish in the aquarium. Aquatics Unlimited cannot accept responsibility for any loss that may occur should this animal poison the aquarium.