Fans of the movie Finding Nemo may recognize this particular species as Gill, a Moorish Idol and the leader of the Tank Gang. This beautiful fish has a flat, disc-shaped body marked by contrasting black, white and yellow vertical stripes similar to the butterfly fish. It is the presence of 6 to 7 elongated spines of the fish’s dorsal fin that sets it apart as well as the orange band at the beginning of their elongated, tubular snout.
They can reach a maximum length of 23 cm (about 9 inches) though most specimens divers encounter are just palm-sized (14-20 cm or 5-8 inches). Moorish Idols mate for life, and reproduce by releasing sperm and egg cells into the water. The larvae floats in the ocean for 10 days, the longest of any reef fish, and may reach up to 7.5 cm before fully becoming free-swimming juveniles.
This subtropical fish prefers reef environments though they can also be seen in coastal lagoons. They can be seen from shallow to deep waters, in cloudy or clear environments. The Moorish Idol can be found throughout the Indo- Pacific region, all the way up to the southern portion of Japan and in the Hawaiian Islands. They are also distributed in areas of East Africa and the southern portion of California. Divers in the Philippines may find Moorish Idols a common sight in dive sites throughout the Visayas region.
Divers may come across these fishes singly, in small groups composed of two to three individuals or occasionally, large schools composed of juvenile males. As the males become adults, they become more and more aggressive towards other males. These reef fishes feed on encrusting animals like sponges and other invertebrates found on the surface of corals and rocks within the reef. They are active during daytime and may be hard to see during night dives since they settle near the bottom.
Sometimes Bannerfish are mistaken as a Moorish Idol, just look for the typical “mask” of the later. They are often spotted around Rock Point at Apo Island.