Orange Kleini Butterflyfish (Chaetodon Kleini) saltwater aquarium fish portrait

Chaetodon kleinii, sold variously as Klein's, Orange, or Sunburst Butterflyfish, is a laterally compressed chaetodontid that reaches roughly 6 inches. Coloration runs from a creamy-white forward section into a golden-yellow posterior body, broken by a dusky-brown vertical band just behind the gill cover, a black band running through the eye, and distinctly black lips. The species is one of the most widely distributed butterflyfishes in the tropical Indo-Pacific, ranging from East Africa and the Red Sea east to the Galapagos, north to southern Japan, and south through Samoa, Noumea, and New South Wales in Australia.

Adults should be housed in an aquarium of at least 125 gallons, with additional volume required if a small same-species group is planned. The layout matters as much as the footprint: this fish wants an open swimming lane along the front of the tank paired with generous live rock to swim through and retreat into when startled. Mature, stable water chemistry with strong aeration and good dissolved oxygen suits it best. It performs well in fish-only-with-live-rock systems and is also kept in reef displays, where its interest in sessile invertebrates should be weighed before introduction.

On the reef, this butterflyfish grazes soft coral polyps, including Sarcophyton and Litophyton species, and supplements that with algae, zooplankton, small mollusks, crustaceans, and worms. It also takes Aiptasia, and some aquarists rely on it to help suppress light infestations of these pest anemones. That mixed omnivorous background translates into an adaptable captive feeder that is rarely fussy once settled.

In the aquarium, build a rotation of frozen mysis shrimp, chopped fresh seafood, other meaty preparations, small crustaceans, and algae-based omnivore formulations. Small meals spread through the day work far better than one or two large feedings; three or more offerings daily keeps condition up in this fast-metabolizing species. Newly imported individuals occasionally need encouragement, and live foods alongside a broadly varied menu usually bring them onto prepared items within a short acclimation period.

Frozen Mysis Shrimp Chopped Fresh Seafood Frozen Marine Preparations Small Crustaceans Algae-Based Omnivore Formulas Live Foods For Acclimation
Klein's Butterflyfish is an active, alert, and peaceful reef fish that spends most of the day cruising rockwork and open water. It mixes well with other peaceful to moderately assertive species and seldom causes trouble among its tankmates. Small conspecific groups are possible when every individual is added at the same time and the display offers enough volume to spread out. Despite its mild reputation, it is an opportunist at heart, and wild fish have been observed mobbing nesting damselfish in groups to raid their eggs.

Around invertebrates, judgment is required. Many aquarists keep this species successfully in reef systems, and observations of interference are often limited to occasional clam nibbling, but polyp-picking on leather corals, other soft corals, and LPS has been reported. Aquarists with valuable soft coral or LPS collections should watch a new arrival closely, while stony-dominant systems and Aiptasia-prone tanks tend to be the most comfortable fit.

FAQ

Frequently Asked Questions

About the Orange Kleini Butterflyfish

  • Can the Orange Kleini Butterflyfish be kept in a reef tank?
    It is generally reef compatible and many aquarists house it in reef displays, though it may sample leather corals, other soft corals, LPS polyps, and occasionally clams. Monitor a new fish closely if you keep prized soft corals or clams.
  • What size aquarium does an adult require?
    Plan on at least 125 gallons for a single adult, arranged with open swimming space in front of substantial live rock. Small same-species groups need considerably more volume and must be introduced together.
  • How often should this butterflyfish be fed?
    Offer several small meals per day, with three or more feedings being ideal. Rotate meaty items such as mysis shrimp and chopped seafood with algae-based omnivore preparations.