Saltwater Aquarist

Yellow Boxfish

(Ostracion cubicus)

Yellow Boxfish

Species Description…

Scientific Name: Ostracion cubicus
Common Name: Yellow Boxfish
Species Group: Boxfish
Habitat: Reef Safe with Caution
Care Level: Advanced
Temperament: Semi-aggressive
Diet Type: Omnivore
Role in Aquarium: Showpiece Fish
Max Fish Length: 18 (inches)
Min Aquarium Size: 150 (gallons)
Native Range: Indo-Pacific, including the Red Sea and Great Barrier Reef

Overview

  • Found in the Indo-Pacific region.
  • Known for their box-like shape and distinctive coloration, which is often bright yellow with black spots in juveniles, turning to a more subdued color in adults.
  • They have a rigid, bony carapace that covers their body.
  • Smooth trunkfish are slow-moving and have a unique swimming style.

Feeding

  • They are omnivores.
  • Their diet includes algae, small invertebrates, and zooplankton.
  • Trunkfish use their small mouths to graze on algae and pick at small organisms.
  • They may also consume sponges and tunicates.

Habitat

  • Smooth trunkfish inhabit coral reefs and rocky areas.
  • They prefer areas with plenty of hiding places and surfaces to graze on.
  • These fish are commonly found in shallow waters.
  • They utilize crevices, caves, and other shelters for protection.

Fish Care

  • Maintaining stable water conditions is important for their health.
  • Providing a varied diet supports their nutritional needs.
  • Regular water quality checks are essential for preventing illness.
  • A well-established tank with ample swimming space and hiding places is beneficial.

Compatibility

  • Smooth trunkfish are generally peaceful but can be territorial, especially towards other trunkfish or similar species.
  • They are best kept with other non-aggressive fish that can coexist peacefully.
  • Care should be taken when introducing them to a community tank.
  • Observing their interactions with other tank inhabitants is advisable.

Aquarium Behavior

  • Smooth trunkfish are slow-moving and have a unique swimming style, often using their pectoral fins for propulsion.
  • Juveniles are particularly colorful and active.
  • They may release a toxin (ostracitoxin) into the water when stressed, which can be harmful to other tank inhabitants.
  • Providing a calm environment and minimizing stress is crucial for their well-being.