Brightly colored butterflyfish are a typical coral reef fish, and they are often seen dashing along the ocean's gardens. They have disk shaped bodies, which is advantageous when navigating through narrow spaces. They can quickly move out of reach for predators, and most species have a dark bar through the eye, which successfully disguises it. Some species of butterflyfish have a false eyespot near their tail. The travel in pairs and mate for life. Despite these long term partners, these fish do not offer parental care for their young. They release their eggs into the water, and after hatching the larvae drifts with plankton for weeks or months. Butterflyfish are distinguished by small, brush like teeth. The family name, Chaetodontidae, is a combination of chaeto ("hair") and dentis ("tooth"). 24 species of butterflyfish are found in the Hawaiian Islands. In ancient Hawai'i, one general name for butterflyfish is kīkākapu meaning "strongly prohibited," and are described in several oli or chants as sacred. Other names are lau-hau, which means "leaf of the hau tree," or lau-wiliwili meaning "leaf of the wiliwili tree."
The Threadfin Butterflyfish is characterized by its whitish body that shades to gold in back. It is also marked with sets of fine right-angled diagonal lines. It gets its name because one of the soft dorsal spines is prolonged into a thread-like filament. Juveniles do not have the filament and have a larger black spot. Pairs of Threadfin Butterflyfish hold home territories where they roam freely. While other species of butterflyfishes are tolerated, those of the same species are driven away. Their species name means "charioteer," which could be due to the whiplike dorsal filament. They grow up to 8 inches.