Chaetodontidae: Butterflyfish Species, ID, Diet, Price

Chaetodontidae is the butterflyfish family: small, deep-bodied, very flat reef fish with bright patterns, including the bannerfish and coralfish. Species counts depend on who you ask, which few pages mention:

• FishBase: 136 species in 12 genera
• Wikipedia: about 129 species in 12 genera
• Animal Diversity Web (University of Michigan): 114 species in 10 genera

The differences come from taxonomy changing over time. Most species belong to the genus Chaetodon (Animal Diversity Web). Butterflyfish live only in salt or brackish water (FishBase), mainly on coral reefs shallower than about 18 to 20 metres, though some go down to 200 metres (Wikipedia; Animal Diversity Web).

Because of their colours and patterns. Wikipedia explains that the name comes from their bright, strikingly patterned bodies in black, white, blue, red, orange and yellow, often with eyespots on the flanks and dark bands across the eyes, much like the markings on butterfly wings.

Check these features in a photo:

• Body: deep and very thin from side to side, like a disc on edge (Wikipedia; FishBase)
• Mouth: small and at the tip of the snout, with brush-like teeth (FishBase); snout length varies with how each species feeds (Animal Diversity Web)
• Eye band: a dark bar running through the eye is typical (FishBase)
• Eyespot: a dark eyespot on the dorsal fin area is typical (FishBase), and many have eyespots on the flanks (Wikipedia). In the Atlantic foureye butterflyfish, a large dark spot ringed in white sits near the tail and acts as a false eye to confuse predators (Florida Museum)
• No cheek spine: this separates them from angelfish, which have a strong spine on the gill cover; butterflyfish lack it (Wikipedia)

The Moorish idol is often sold alongside butterflyfish, but it is in a different family. FishLens suggests a name from one photo.

Diets vary more than their similar shapes suggest. Most species eat coral polyps and sea anemones, some specialise in zooplankton, and others take small invertebrates, fish eggs, sponges or algae (Wikipedia; FishBase; Animal Diversity Web). The foureye butterflyfish, for example, picks worms, zoanthids, gorgonians and tunicates from reef crevices (Florida Museum).

They are active by day and usually seen in pairs. Animal Diversity Web notes that many pairs stay together for at least three years and some may pair for life; separated foureye partners actively search for each other (Florida Museum). Spawning happens in open water, and the larvae pass through a tholichthys stage covered in bony plates that they lose as they grow (Wikipedia).

Not towards people, but many are territorial towards other fish. Wikipedia describes coral-eating species forming pairs that defend particular coral heads, while plankton-feeding species gather in larger groups. In an aquarium this means two butterflyfish of the same or similar species may fight, and species that eat coral polyps and anemones will eat them in a reef tank too. Ask the seller whether the species you want is kept singly or in pairs.

Most common aquarium species cost $20 to $140. Starting prices at LiveAquaria when we checked on 25 September 2026:

• Vagabond butterflyfish from $21.99
• Orange butterflyfish from $31.99
• Pearlscale butterflyfish from $49.99
• Auriga butterflyfish from $53.99
• Raccoon butterflyfish from $59.99
• Yellow longnose butterflyfish from $69.99
• Heniochus (black and white bannerfish) from $79.99
• Copperband butterflyfish from $89.99
• Yellow pyramid butterflyfish from $139.99

The purchase price is the smaller cost. FishBase warns that most species are difficult to keep and obligate coral-eaters are nearly impossible, and LiveAquaria notes that some need live coral polyps to eat and a large tank with hiding places. Before buying, ask the seller to show the fish eating prepared food.

Butterflyfish are not described as food fish in FishBase, Wikipedia or Animal Diversity Web; their value to people is as reef and aquarium fish. They are also small, mostly 12 to 22 cm. If you are ever offered reef fish to eat, remember that ciguatoxin cannot be seen, smelled or tasted and is not destroyed by cooking or freezing (Clemson University Home and Garden Information Center). Check local advice, and see a doctor if you feel ill after eating reef fish.

Because many butterflyfish depend on live coral, they are closely tied to reef health. Animal Diversity Web notes that as of 1994 five butterflyfish species, all in the genus Chaetodon, were listed as vulnerable, mainly because of their small ranges.

Research and drafting for this page were assisted by AI and checked line by line against the sources listed below. Every number names the organisation it comes from, and where sources disagree we say so instead of picking one silently. Prices and rules are given with the date we checked them; they change, so confirm before you rely on them. If you find an error, tell us and we will correct it.