SpinyheadPlay freeFoureye butterflyfish Chaetodon capistratus
The foureye butterflyfish is a small, disc-shaped reef fish of the western Atlantic, named for the large black spot ringed in white on each side of its rear body. This false eye spot, combined with a dark stripe through the true eye, is thought to confuse predators about which end is the head and which way the fish will flee. It is a common, conspicuous species that is often seen alone, in pairs, or in small groups browsing over the reef. The body is pale gray to yellowish with fine diagonal lines that form a chevron pattern.
How to recognize it
- large black spot ringed in white near tail
- dark vertical bar through the true eye
- laterally flattened, round body
- pale gray-yellow body with diagonal dark lines
- yellow edge on the pelvic and anal fins
- small pointed snout
- often seen in pairs
| Size | Typically about 8 to 13 cm long; maximum about 15 cm. |
|---|---|
| Range | Western Atlantic, from Nova Scotia and Massachusetts south through Florida, the Gulf of Mexico, Bahamas and Caribbean to the northern coast of South America. It is most common in the Caribbean and Florida, and northern records are mostly juveniles that drift north. |
| Habitat | Found on coral reefs, rocky areas and seagrass-adjacent reef edges, from very shallow water to roughly 20 m or a bit deeper. It is most often seen over shallow to mid-depth reef flats and patch reefs where there are plenty of crevices for shelter. |
| Diet | Omnivorous, picking at small prey with its pointed snout and fine teeth. It eats small invertebrates such as polychaete worms, small crustaceans, and anemones, along with coral polyps, algae and fish eggs. It often probes into crevices and among corals and gorgonians to pick off food. |
| Conservation | The foureye butterflyfish is listed as Least Concern by the IUCN. It is widespread and common, though it can be affected by reef degradation and coral loss, and it is collected for the aquarium trade. |
Life and behavior
Adults commonly form pairs that may stay together for long periods and defend a feeding area. Spawning takes place near dusk, when pairs rise into the water column and release eggs and sperm. The eggs are pelagic and the larvae drift in the plankton before settling on the reef. The young have a distinctive bony-plated larval stage known as the tholichthys stage, which is characteristic of butterflyfishes. At night the fish hide in the reef and often become paler or show darker blotches.
Its family: Butterflyfishes (Chaetodontidae)
Butterflyfishes are small, deep-bodied, strongly flattened fishes of tropical reefs, often brightly patterned. They have small mouths with brush-like teeth suited to picking at small prey or coral polyps. Many species form long-lasting pairs. Their larvae pass through a bony-headed tholichthys stage.
Similar species
- Spotfin butterflyfish Chaetodon ocellatus Mostly white to pale yellow with a black bar through the eye and a dark spot only on the soft dorsal fin, not a large ringed spot on the rear body; it grows larger.
- Banded butterflyfish Chaetodon striatus Has two broad dark vertical bands on a white body, and lacks the ringed eyespot.
- Reef butterflyfish Chaetodon sedentarius Has a yellowish body and a dark band through the eye, with a dark mark near the rear dorsal fin but no large white-ringed spot; it is more often seen on deeper reefs.
