Most people are aware of the Hawaiian state fish, the humuhumunuknukuapua‘a, but they don’t realize we have several different types of trigger-fish that all begin with the Hawaiian name humuhumu. These fish all have a sharp spine on their back that becomes erect when they become threatened. They all can dart into a hole or crack in the lava reef then “trigger” their spine to lock into place so they are impossible to pull backwards out of the hole! Most of the trigger=fish sleep by themselves in holes in the reef where they are safe from being eaten by sharks and moray eels.
The black trigger-fish is often found during the day mid water in schools of 10 or more, and they use their soft dorsal and anal fins in a wave-like motion to undulate through the water, feeding on floating algae. They will also eat green peas, and some of the snorkel tour boats dump frozen peas into the water around the boat to attract hundreds of these fish up close to the snorkelers. When you see them in the blue water they look pitch black, but if you get close to them they have beautiful blue, green and yellow lines between the black scales. They become more colorful when breeding or chasing each other around to protect their territory.
Due to the lack of letters in the Hawaiian alphabet, many Hawaiian names are repeated, but each name has a different meaning. “Humu” means “stitched pattern,” as the trigger-fish have a pattern that looks like the stitching on a dress. The second “humu” means “passageway,” because the fish knows all the passageways through the reef. The name “humu” comes from an ancient star called the humu star that had its own passageway through the galaxy. The name “ele” means “black” because the fish looks black, but this fish has “ele” repeated twice, so there must also be a second meaning of “ele.” As of yet I have not been able to find what this second “ele” means, so if anyone out there who is an expert with the Hawaiian language and knows the meaning, please let me know.
The skin of the black trigger-fish is so abrasive it can be dried and used as sandpaper! The trigger-fish are closely related to the file-fish that were used in old Hawai‘i to file down wood for canoe-building. If you were to catch one of the humuhumu ‘ele‘ele and grab it you would think you had a hard lava rock in your hands and not a fish!
You can see the black trigger-fish in action in the movie “The World’s Guide To Hawaiian Reef Fish” on the web, and follow my weekly marine-life Instagram posts at terry.lilley.
Terry Lilley is a marine biologist living in Hanalei. He is co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawai‘i go to reefguardianshawaii.org.