Butterflyfish: Bold and Beautiful
Endemic Milletseed Butterflyfish, shot by Valerie Hartman
The delicate and brightly colored Butterflyfish stand out as some of the most beautiful reef fish you will encounter while SCUBA diving or snorkeling. More characteristic of coral reefs than any other family of fishes, these brightly colored and intricately patterned fish are an underwater delight!
Recognizing Butterflyfish is easy. Look for yellow coloration and bold patterns that conceal certain body features. There is often a dark bar near the eye as well as the tail. These dark markings, called a "blind eye", confuse predators as to which part of the fish is the Butterfly's head or tail. The disc-shaped body is designed to move quickly, especially into and out of tight places in the lava rock and corals. The family name, "Chaetodontidae", refers to the long snouts with highly modified brush-like teeth, designed to feed in small places.
Most of the Butterflyfish species (24 in Hawaii) feed during the day on a diet consisting of either plankton, small bottom-dwelling invertebrates, or coral. The major benefit these fishes get from their bright and distinctive colorations is the ability to recognize their own kind for mating. The coral feeding types of Butterflies will be seen in pairs and are considered monogamous, remaining with the same mate year after year. This strong mating bond is unique to this family of fishes.
Longnose Butterflyfish, shot by Jessie at Explore Kaua'i SCUBA
The bold Butterflyfish can be easily observed because they are territorial and not normally scared by divers. The Racoon Butterfly or "Ki kakapu" were mentioned in spiritual chants and were "strictly forbidden" in old Hawaii. It is unknown whether this was due to their strong fin spines which would give fishermen a prickly mouthful or because they were sacred.
Marine Biologists who study coral reefs in tropical waters use population studies of Butterflyfish as an indicator of coral health. A visual census of these coral feeders can help monitor small changes, due for example to a chronic low level of pollution that would be difficult to detect by a human observer.
Feeding these fish is not recommended as it upsets the natural balance and chemistry of the water in an area. We do know, however, that the Butterflyfish have existed on Hawaiian reefs for millions of years. Several common species like the milletseed butterflyfish are endemic, that is, unique to the islands. These "local" representatives tend to be the most successful and abundant members of their family.
You are almost certain to encounter this delightful class of fish when you don a mask and enter the water here in the Hawaiian Islands.
