The beauty of reef diving is found in the colors of the coral and the vibrancy of the fishes that call it home. Some divers are content to just enjoy the sights. But as divers start filling up their dive logs, knowing the names of the marine life they encountered becomes more important. New divers may be able to identify a type of fish. More experienced divers start to distinguish between the various species within that group. Butterflyfishes help create that tropical experience divers can only find on coral reefs—and with Jupiter Dive Center, you can see them for yourself. Here's how to know what you’re looking at.
How to identify butterflyfishes
Well, the short answer is, it depends. There are at least 114 species of butterflyfish (also known as butterfly fish) across the globe, and depending on the species, they come in a wide variety of colors and patterns. Like angelfish, they have thin disc-like bodies and may have long, thin snouts. Unlike angelfish, butterflyfish have a concave forehead.
Florida species tend to be more subdued than the Indio Pacific species, and are often silver or white with yellow tints. Many have bands that run across the eye area, which helps camouflage the eye, and large dark spots (ocelli) near their tail fin—which may help confuse the larger fish, eels, and sharks that prey on them. When agitated, they are capable of making their colors brighter. Those same colors and their varied patterns make them popular aquarium fish.
Butterflyfish are most commonly found in pairs, but at times swim on their own and very occasionally, school. They rarely exceeding eight inches—and Florida species rarely exceed six. Reef dwellers, their swim style is best described as flitting and darting. They are most active during the day and can be territorial. At night, they sleep in reef crevices and hiding spots. Butterflyfish are omnivores and feed on plankton, plant matter, small crustaceans and coral polyps.
The lifespan of a butterflyfish is anywhere from five to ten years and their average clutch of eggs numbers two hundred. As with many marine animals, butterfly fish are considered endangered species, and the biggest threat to their existence is the destruction of coral reefs.
What Species Call Jupiter Home?
The banded, bank, foureye, reef, and spotfin butterflyfishes can all be found in Florida waters.
No description can compete with a photograph, and butterflyfishes are depicted on fish identification slates that divers can take on their reef dives. Topside, there’s no better resource than Paul Humann and Ned Deloach’s Reef Fish Identification for Florida, Caribbean, and Bahamas book. Serious divers will want to expand their collection to include the author’s corals and marine creatures books as well.
That said, sometimes it’s nice to have distinctions spelled out. Let’s start with the foureye butterflyfish. Adults typically range from three to four inches, and have two wide, black midbody bands in addition to the band on the head that runs across their eyes. A white-ringed spot decorates the base of the rear dorsal fin. Fins are fully or tinged in yellow. Young juveniles have a second, smaller white-ringed spot on rear dorsal above the larger spot. They tend to range from one and a half to two and a half inches. Both adults and juveniles are most commonly found at depth that ranges from 10 – 60 feet.
Banded butterflyfish adults are a bit larger and often hit five inches. They have the two bands, but no spots. The juveniles, do have a spot in the rear, but unlike the foureye, they don’t have any yellow fins.
Reef and spotfin butterflyfish have a dark band across their eyes, but not the body bands like earlier fish. An easy way to tell these two similar species apart is that the spotfin, has a small spot on the outer edge of the rear dorsal fin. The reef butterflyfish has a band over the rear of its dorsal and anal fins. Both have white bodies and yellow fins.
The bank and longsnout butterflyfish are uncommon in Florida and they differ from the more common species in that they have longer snouts and prefer deeper reefs. Banks have a white body, yellow fins, an eye band, and a dark body band that extends from the middorsal fin to the rear anal fin. The longsnout is white bellied, but yellow-bodied which turns rusty and dark on its dorsal fin. It also sports a dusky yellow eye band that depending on the hue of its body can be difficult to see.
Confused yet? Don’t worry. It takes time to distinguish species—especially small ones.
So if you prefer your marine life larger, you’re in luck! Goliath grouper aggregation begins in August, and is truly a bucket-list dive!
Big or small, there is always something to see. Book your dive with Jupiter Dive Center, now!