Cowfish & Boxfish

Curious and Colorful Marine Characters

Cowfish and Boxfish are among the ocean’s most fascinating saltwater aquarium species, easily recognized by their box-shaped bodies and charming, curious personalities. Their slow swimming style and bright coloration make them standout additions to large, peaceful marine aquariums.

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At AquariumFish.com, we offer a variety of Cowfish and Boxfish for sale, including popular species such as the Longhorn Cowfish, Yellow Boxfish, and Spotted Boxfish. Known for their intelligent, interactive behavior, these fish often learn to recognize their keepers and can be seen exploring every corner of their aquarium.

Despite their playful appearance, Cowfish and Boxfish require special care. They produce a mild toxin (ostracitoxin) when severely stressed, so they are best housed in large, calm aquariums with peaceful tankmates. With proper tank size, good water quality, and a stress-free environment, these fish thrive and live long, healthy lives.

Why Choose Cowfish and Boxfish?

  • Unusual body shape and vibrant patterns that attract attention
  • Curious, intelligent behavior — great for interactive aquariums
  • Peaceful temperament when housed with non-aggressive species
  • Great centerpiece fish for large marine tanks

Care Tips for Cowfish and Boxfish

  • Provide a tank of 100 gallons or more with plenty of swimming space
  • Maintain stable water parameters and excellent filtration
  • Feed a varied diet including marine pellets, frozen mysis, and algae-based foods
  • Avoid aggressive or nipping tankmates such as Triggers or Puffers
  • Minimize stress — avoid sudden movements or chasing during feeding and cleaning

Popular Species We Offer

  • Longhorn Cowfish (Lactoria cornuta) – iconic yellow body with long horns and a gentle nature
  • Yellow Boxfish (Ostracion cubicus) – bright yellow with black spots; one of the most recognizable marine fish
  • Spotted Boxfish (Ostracion meleagris) – black body with white spots and unique male/female coloration
  • Blue Boxfish (Ostracion cyanurus) – small, colorful species suitable for peaceful reef-style tanks

Cowfish and Boxfish are truly one-of-a-kind marine species that bring character, color, and charm to any aquarium. With gentle care and the right setup, these slow-moving, personable fish will become the stars of your tank.

Explore related collections: Saltwater Oddballs · Pufferfish · Triggerfish · Tangs · Saltwater Fish

Cowfish & Boxfish FAQs

Are Cowfish and Boxfish reef-safe?
Not entirely. While they generally ignore corals, they may nip at small invertebrates or coralline algae. They are best kept in fish-only or FOWLR aquariums.
Do Cowfish and Boxfish release toxins?
Yes — when severely stressed or injured, they can release a mild toxin called ostracitoxin. This is rare in calm, well-maintained aquariums with proper tankmates.
What fish can live with Cowfish and Boxfish?
Peaceful, slow-moving tankmates such as Gobies, Wrasses, and smaller Tangs make good companions. Avoid aggressive species that might chase or nip at them.

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