Raccoon Butterflyfish (Chaetodon lunula)

The Raccoon Butterflyfish, also known as the Crescent-masked Butterflyfish, is one of the most recognizable and hardy species in the Chaetodon family. In Indonesia, they are a common sight on shallow reef flats and seaward reefs. While they are stunningly beautiful with their "masked" appearance, they are "double-edged swords" in the hobby: they are legendary for eating aquarium pests like Aiptasia, but they are equally famous for eating prized corals.

Key Information

• Common Names: Raccoon Butterfly, Crescent-masked Butterfly, Moon Butterfly

• Scientific Name: Chaetodon lunula

• Origin: Indo-Pacific (Red Sea to Hawaii, very common in Indonesia)

• Max Size: 18–20 cm (approx. 7–8 inches)

• Lifespan: 7–10 years

• Temperament: Peaceful; can be shy or social

• Diet: Omnivore – Specialist in invertebrates and coral polyps

• Care Level: Easy to Moderate

Appearance & Identification

The Raccoon Butterfly is named for its distinct facial markings that resemble a raccoon's mask:

• The Mask: A bold black band runs through the eye, followed by a wide white band, and then another dark crescent-shaped patch behind the head.

• The Body: A base of glowing golden-yellow with several reddish-brown diagonal stripes running upward toward the back.

• The Tail: Features a black spot on the tail base (caudal peduncle) and a black band on the tail fin itself.

• Nocturnal Shift: Interestingly, this species is somewhat nocturnal in the wild. When the lights go out, their colors may dull, and they become more active hunters of small invertebrates.

Behaviour & Tank Compatibility

• The Aiptasia Terminator: If you have an infestation of Aiptasia (glass anemones) or Majano anemones, the Raccoon Butterfly is one of the most effective biological controls available. They will hunt them down with surgical precision.

• Reef Safe (No): This fish is not reef safe. It will eagerly eat Zoanthids, meaty LPS corals (like Brain corals or Acans), and Feather Dusters. It is generally only kept in "Fish Only With Live Rock" (FOWLR) systems or very specific "Pest Control" scenarios.

• Social Structure: Can be kept singly or in pairs. They are peaceful toward most other fish but can be territorial toward other butterflyfish of similar shape.

• Tank Mates: Excellent with Tangs, Angelfish, and larger Wrasses. Avoid very small, timid fish that might be intimidated by its size.

Ideal Tank Setup

• Tank Size: A minimum of 285L (75 Gallons) is required for a single adult.

• Rockwork: Provide a complex reef structure with large caves. Since they are naturally active at dawn and dusk, they appreciate shaded areas to "hang out" during the brightest part of the day.

• Water Quality: They are hardier than many other butterflies but still require stable parameters and high oxygenation.

• Lid: Like most thin-bodied reef fish, they can jump if startled. A secure lid is recommended.

Dietary Needs

They have broad appetites and are usually very easy to feed:

• Diet: Offer a variety of meaty frozen foods (mysis, brine shrimp, chopped clam, and squid).

• Grazing: They appreciate algae-based foods and will spend time picking at the rocks.

• Specialty: If they are being used for pest control, they will naturally forage on the Aiptasia in the tank.

Why Choose the Raccoon Butterfly?

The Raccoon Butterfly is for the hobbyist who wants a hardy, iconic centerpiece for a non-coral tank. Its bold mask and golden body make it a standout in any display. For those in Wonosobo looking for a locally available fish that is easy to transition to aquarium life, the Raccoon is a fantastic choice—just keep it far away from your favorite corals!