Description

Scientific Name: Chaetodon mertensii

Common Names: Merten’s Butterflyfish, Merten’s Butterfly, Black-tipped Butterflyfish

Maximum Length: 6 inches (15 cm)

Minimum Aquarium Size: 75 gallons (284 liters)

Aquarium Suitability: The Chaetodon mertensii is well-suited for larger reef or fish-only aquariums with peaceful tank mates. This species is best kept in tanks with a minimum size of 75 gallons to provide enough swimming space. It thrives in established tanks with plenty of live rock for hiding and grazing. It is best housed with other non-aggressive species, as it can sometimes display territorial behavior towards similar-looking butterflyfish.

Foods & Feeding: The Merten’s Butterflyfish is primarily a carnivore, feeding on small invertebrates, zooplankton, and coral polyps. In captivity, it will accept a variety of foods, including high-quality frozen preparations like mysis shrimp, brine shrimp, and other meaty foods. Providing a varied diet, including occasional live foods like copepods, will ensure that the butterflyfish remains healthy and active. It may also nibble on soft corals or invertebrates in a reef tank, so be mindful of its feeding habits.

Reef Compatibility: While the Chaetodon mertensii is generally reef-safe, it can be a bit of a challenge in reef tanks with delicate or small invertebrates, as it may occasionally nip at corals, especially softer varieties. It is best suited for aquariums with more robust corals that can withstand occasional grazing. The fish’s peaceful nature towards other tank inhabitants makes it a suitable addition to a well-maintained reef tank with plenty of hiding spaces.

Captive Care: This species is relatively hardy but requires stable water parameters and a well-established aquarium environment. It’s important to offer plenty of live rock and hiding places in the aquarium to reduce stress and encourage natural behavior. The Merten’s Butterflyfish is known to be a bit shy, especially when first introduced to a new tank, so it may take some time to acclimate.

A beautiful and colorful addition to a larger reef aquarium, the Chaetodon mertensii provides both visual appeal and beneficial pest control. Its peaceful demeanor, combined with its striking appearance, makes it a captivating choice for aquarists seeking a vibrant butterflyfish for their setup.

Fun Facts

• The Mertens’ Butterflyfish’s black chevron patterns resemble delicate brushstrokes, enhancing its artistic appeal in aquariums.
• In the wild, it often pairs with a mate, swimming closely together in a synchronized dance over atoll reefs.
• Its vivid yellow coloration can intensify with a nutrient-rich diet, making it a standout under bright tank lighting.