Chaetodon kleinii – Klein’s Butterflyfish

Klein’s Butterflyfish (Chaetodon kleinii) is a hardy and active butterflyfish originating from the Indo-Pacific region. It is one of the more adaptable butterflyfish species for aquarium life and usually accepts a wide variety of foods, making it a suitable option for aquarists interested in keeping butterflyfish.

The species is easily recognized by its yellowish body coloration, a dark band running through the eye, and a distinctive black spot near the rear of the dorsal fin. In the aquarium it spends most of its time swimming in open water and adds movement and character to larger marine setups.

While relatively robust, Klein’s Butterflyfish is not considered fully reef-safe, as it may nip at coral polyps and certain invertebrates. It is therefore better suited for fish-only systems or aquariums where occasional coral nipping is acceptable.

Key Features

• Hardy butterflyfish species compared to many others in the group
• Active swimmer that thrives in spacious aquariums
• Distinct yellow coloration with black eye band and dorsal spot
• Generally adapts well to frozen and prepared foods

Care Requirements

• Minimum aquarium size: ~300 L
• Temperament: Peaceful, but may be territorial toward other butterflyfish
• Diet: Omnivore – accepts frozen foods (mysis, artemia), marine pellets, flakes, and algae-based foods
• Reef compatibility: Not fully reef safe; may nip at corals

Additional Notes

Provide ample swimming space together with rock structures for shelter. Once acclimated, Chaetodon kleinii is typically an active and long-lived addition to marine aquariums.

Approximate adult size: up to 12–15 cm.