Koh Tao underwater: Butterfly fishes (Family Chaetodontidae)

Butterflyfishes are thin, tall, and plate-like. They are opposite shape of a shark’s mouth, which illustrates how important a role predation has played in their evolution. To further avoid predation, the tail of most butterflyfish looks just like the head, and often they have a line over their eye for disguise. Together this confuses predators, who don’t know which way the fish is going to swim away.

Butterflyfish are the easiest fish to spot on our dive sites and usually occur in pairs but sometimes can be found in schools.

The most common for Koh Tao is the Lined Butterflyfish, which is one of the biggest butterflyfishes and can reach 30 cm in length,
Copperband Butterflyfish (also known as Beaked Coralfish) with a long narrow nose and beautiful copper and orange bands on white body,

Weibels Butterflyfish with bright yellow-orange body, they can be seen in large groups at Shark Island and is favorite amongst photographers.
Longfin Bannerfish which is often mistaken for a Moorish Idol (which belongs to the family of Zanclidae). The fish colored in black and white, with an elongated dorsal fin, sometimes reaching a length of 20 cm. The caudal, anal and pectoral fins are often bright yellow.

Butterflyfish feed on coral polyps, macro-invertebrates, and algae, so live only in healthy reef areas. In many areas they are a prized fish for the aquarium trade due to their bright colors, but on Koh Tao are mostly threatened by fishing activities or habitat destruction.