Thornback Cowfish

The Thornback Cowfish is a uniquely shaped member of the Ostraciidae (boxfish) family, found on deep coastal slopes with muddy or silty substrates and sometimes in shallower seagrass beds. It feeds on benthic invertebrates and various algae, grows to a substantial size, and requires a very spacious fish-only aquarium. Generally solitary, it can become quite tame, and its unusual swimming style adds to its appeal. Juveniles display bright colors that become more subdued as they mature.

Like other boxfish, the Thornback Cowfish can release a toxin when stressedpotentially harmful to all tank inhabitantsso it must be handled with great care and housed with peaceful tankmates that will not harass or outcompete it for food. Fortunately, it is less prone to toxin release than many of its relatives. Once comfortable in its environment, it may spit water at the surface when expecting a meal. Keep only one per aquarium and avoid mixing it with similar species. It is also known by a variety of other names, including hovercraft boxfish, camel cowfish, helmet cowfish, and thornback boxfish.

An omnivore, the Thornback Cowfish should be offered small meaty foods like Mysis shrimp, Spirulina-enriched brine shrimp, and chopped prawns, krill, mussels, cockles, or squid, alongside herbivore fare such as marine algae. Avoid floating foods to prevent accidental air ingestion, which can lead to buoyancy problems. Feed small amounts three times per day.

Currently feeding on EMA Mega Mix