Raccoon Butterflyfish
Chaetodon lunula
Also known as Crescent-masked Butterflyfish, Halfmoon Butterflyfish, Lunule Butterflyfish
Care at a glance
- Temperature
- 75–81°F (24–27°C)
- pH
- 8.1–8.4
- Adult size
- 7.9 in (20 cm)
- Minimum tank
- 106 gal (400 L)
- Temperament
- Mostly peaceful
- Social behavior
- Solitary
- Swim level
- Middle
- Difficulty
- Medium
- Breeding
- No record
- Rarity
- Common
- Reef safe
- Not reef safe
- Origin
- Indo-Pacific and Red Sea reefs, from East Africa to Hawaii and the Marquesas, south to Lord Howe Island
- Family
- Chaetodontidae
Overview
Not reef safe: it is one of the more food-driven butterflyfish and will pick at soft corals, large-polyp stony corals, anemones, tubeworms, and clam mantles, so it belongs in a fish-only or fish-only-with-live-rock system rather than a reef tank. It can be a bit more assertive at feeding time than other butterflyfish and may squabble with its own kind unless a pair is introduced together, but it otherwise mixes well with similarly sized tankmates. It is a strong eater once settled, taking mysis, chopped seafood, marine pellets, and algae-based foods, though newly imported fish sometimes need a few quiet, dimly lit days before they start feeding on their normal nocturnal schedule.
In the wild
Found across the Indo-Pacific and Red Sea from East Africa to Hawaii and the Marquesas, north to Japan and south to Lord Howe Island, on lagoon and seaward reefs where it shelters under coral ledges and in caves by day. It is mostly nocturnal in the wild, becoming most active around dusk, so it should be given plenty of rockwork with caves and overhangs to retreat into during the day. It also needs a well-established tank, since it is sensitive to copper-based medications and poor water quality. A tank of at least 400 litres (106 US gal) suits a single fish.
Good to know
Named for the black bandit-mask marking across its eyes, which resembles a raccoon's face, paired with a black crescent edged in white just behind it, the marking that gives the species its name lunula, or little moon. It reaches about 20 cm and, like many nocturnal reef fish, can shift into a duller, blotchy night pattern that helps it blend into the reef while it rests.
Did you know
Its nocturnal habits are strong enough that new arrivals often hide through the first several days in a tank and only come out to feed as the lights dim, which can look like a sick or stressed fish when it is really just running on a reef-appropriate schedule.
Where to buy
Some links may not be the exact species or variety.
- LiveAquaria Freshwater and saltwater fish, inverts and corals
- Saltwaterfish.com Marine fish, corals and inverts shipped overnight
- Biota Captive-bred marine fish, corals and clams shipped direct
…or ask your local fish store.
Appears in
Keeping Raccoon Butterflyfish?
Track water tests, reminders and stocking fit.
Related species

Collare Butterflyfish
Chaetodon collare7.1 in (18 cm)90 gal (340 L)73–81°F (23–27°C)
Threadfin Butterflyfish
Chaetodon auriga9.1 in (23 cm)79 gal (300 L)75–81°F (24–27°C)
Golden Butterflyfish
Chaetodon semilarvatus9.1 in (23 cm)151 gal (570 L)75–82°F (24–28°C)
Klein's Butterflyfish
Chaetodon kleinii5.9 in (15 cm)79 gal (300 L)75–81°F (24–27°C)
Pearlscale Butterflyfish
Chaetodon xanthurus5.5 in (14 cm)75 gal (285 L)73–81°F (23–27°C)
Milletseed Butterflyfish
Chaetodon miliaris5.1 in (13 cm)75 gal (285 L)72–79°F (22–26°C)
