Dive for the Key West Four-eyed Butterflyfish

Going on a Key West scuba diving tour is the highlight of many tourists' trip to Florida's southernmost key. Though there is a plethora of underwater life to be seen on one of these diving trips, the Foureyed Butterflyfish, much like its close cousin the Banded Butterflyfish, is one of the most common reef fish and a staple of many dives.

Otherwise known by its scientific name of Chaetodon capistratus, the Foureyed Butterflyfish got its name from the two false eyes painted onto its back. These large black spots have white rings around them and are in fact larger than the fish's real eyes. They are designed to fool predators into thinking their tail is actually their head. The real eye has a vertical stripe covering it, further hiding it. They are usually a light gray with hints of yellow throughout their body, and adults are covered with forward pointing v-shaped stripes. Juveniles lack these stripes. They also have a yellow ventral fin, contributing to their cheerful appearance.

The Foureyed Butterflyfish, also known as the butter bun or the school mistress, has a round, flat body and a long snout-like face. It also has a concave forehead and bristly teeth and spines, making it an unattractive meal. That fact coupled with its ability to dart between reefs, swimming horizontally or even upside down in order to navigate narrow passageways, helps to protect it from many predators. When threatened its first impulse is to run away rather than fight back, which is why it might also hide when it sees a diver coming towards it.

They eat mainly invertebrates, including soft coral and sea worms. Mostly active during the day, this fish likes to find seagrass beds or reef to hide in when sleeping at night. It is found mainly in the warm tropical and subtropical waters of the western Atlantic Ocean and the Gulf of Mexico, including the Florida Key area, and can live up to 10 years.

Sentimental visitors or divers on a honeymoon trip might enjoy knowing that the Foureyed Butterflyfish mate for life and are monogamous. They become sexually mature at just under four inches, and generally are seen swimming around in pairs with their mate. If they lose sight of that mate, they will make an effort to find him or her. Spawning season is between February and May and involves the fish circling each other before playfully chasing each other around the reef. When they are ready they release their sperm and eggs into the water, generally at dusk. The females can release up to 4000 eggs at once, which hatch after a day. One additional day results in the newly hatched gray armored larvae turning into juvenile fish.

While these aren't the only reef fish a diver is going to see, they are a common addition to any diving trip. Though a bit shy of close contact and sometimes difficult to properly feed, their peaceful demeanor and bright pattern make them popular aquarium fish. Divers don't need to worry about that though, and can simply enjoy watching these fascinating creatures in their natural habitat.