Kihikihi: The Moorish Idol of Hawaiian Reefs
Meet the Kihikihi
With bold black and yellow bands and a long, trailing white dorsal fin, the kihikihi is a striking sight on a Hawaiian reef. Known in English as the Moorish idol (Zanclus cornutus), this fish is common in Hawaiʻi, where reef watchers may see it swimming alone or in small groups.
Its appearance makes it memorable, but can also lead to mistaken identity. The Moorish idol resembles certain butterflyfishes, yet belongs to a different family. Knowing which markings to look for makes this fish easier to recognize.
What Does Kihikihi Mean?
The Waikīkī Aquarium explains that the Hawaiian name kihikihi can refer to curves, corners, angular shapes, and zigzags. The name may describe the fish’s shape as well as its dramatic pattern. Its high body, contrasting bands, and extended dorsal fin give it an unmistakably angular outline.
How to Identify a Moorish Idol
Rather than relying on the long fin alone, look for a combination of features:
- Body: A high, oval profile with alternating black and yellow bands.
- Upper jaw: A distinctive orange saddle marking.
- Dorsal fin: An elongated white extension that trails above the body.
- Tail: Black, an especially useful detail when comparing similar-looking fish.
When watching from above the water, the contrasting colors may be easier to notice than the smaller markings. If you can see the head and tail clearly, those details help confirm the identification.
Moorish Idol or Banner Butterflyfish?
A banner butterflyfish can have a similar shape and long dorsal fin. According to the Waikīkī Aquarium, the Moorish idol’s orange jaw marking and black tail distinguish it from the banner butterflyfish’s white jaw and yellow tail.
Behavior offers another clue: Moorish idols commonly forage near the reef and seafloor, while banner butterflyfish feed on plankton higher in the water column. Use these clues together rather than identifying a fish from its silhouette alone.
Where Kihikihi Live
Kihikihi occur in Hawaiian waters from shallow areas to depths of about 600 feet. Snorkelers and divers may encounter them around reefs, while people watching from shore can sometimes see them foraging in rocky shallows and boat harbors.
They may swim alone or in groups of four to six. Although associated with Hawaiian reef scenes, Moorish idols are not found only in Hawaiʻi: their distribution extends across the Indo-Pacific and into the tropical eastern Pacific.
What Do Moorish Idols Eat?
Moorish idols are omnivores, with a diet that includes substantial animal material such as sponges. Their slightly elongated jaws help them extract food from reef crevices.
This feeding behavior is a useful reason to watch patiently. Instead of only following the trailing fin, notice where the fish directs its mouth and how it searches the reef’s uneven surfaces.
A Reef Fish in a Family of Its Own
The Moorish idol is the only species in the family Zanclidae. Despite its resemblance to butterflyfishes, it is more closely related to surgeonfishes. Unlike those relatives, it lacks their characteristic scalpel-like structure near the tail.
For a comparison with Hawaiian surgeonfishes, explore our guides to Manini, the convict tang and Kole, the yelloweye tang.
Explore More Hawaiian Reef Life
Our Hawaiian Reef Fish Playing Cards bring reef fish to the table through watercolor illustrations and Hawaiian and English names. Explore the deck as a way to keep learning about the fish of Hawaiʻi between visits to the ocean.
Source
Waikīkī Aquarium: Moorish Idol, used for identification, Hawaiian name interpretation, habitat, distribution, diet, and classification.