Ocean Watch
By Susan Scott
Monday, September 13, 1999
Trumpetfish have been nudging me to write about them lately. While snorkeling in a secluded spot on the Big Island recently, my partner gestured to an underwater cave. When I dove down to check it out, I found myself face to face with the biggest trumpetfish I have ever seen. Trumpetfish often
surprise people or preyThis fish seemed between 3 and 4 feet long and as big around as my leg. The fish and I watched one another for a few seconds, then with a flutter of fins, it was gone.
When I got home, I learned that Hawaii's largest trumpetfish grow to a maximum of 30 inches long, making my nearly 4-foot-long estimate a typical fish story.
Then last week, while snorkeling with my family near Chun's Reef, I swam off on my own. "See anything interesting?" I asked my sister when we reunited.
"Yes," she said. "A trumpetfish."
Even though they are quite common, trumpetfish are indeed interesting. These long, narrow carnivores often hang vertically and motionless in the water like so many sticks. When an unsuspecting fish or shrimp swims close, the "stick" comes alive and sucks up its prey like a vacuum cleaner.
This suction method of eating is so powerful that divers can sometimes hear a whooshing sound when it happens. Once, a photographer friend, David Schrichte, not only heard it but also got a picture of an unlucky squirrel fish getting hoovered into a trumpetfish's mouth.
Trumpetfish have other unique hunting methods. Sometimes, a trumpetfish will use a school of surgeonfish as a blind. The trumpetfish drifts in the middle of a moving, grazing school, thus maneuvering close to an unsuspecting prey. When it gets close enough, the trumpetfish sucks it up.
I saw this happen recently while snorkeling at Shark's Cove. In the center of a larger school of whitebar surgeonfish and convict tangs hung a large trumpetfish, looking like a piece of driftwood. Its vacuum strike was so fast I didn't even see what the fish swallowed.
In yet another ploy to get close to prey, a trumpetfish will cruise alongside a butterflyfish or pufferfish. This may not seem effective except that trumpetfish blend into their backgrounds amazingly well.
Besides their sticklike shape, many trumpetfish are a gray-brown color, matching dark reef bottoms and other dark fish nearly perfectly. Other trumpetfish are the same vivid yellow as the butterflyfish and yellow tangs they swim with.
Researchers don't know if trumpetfish can change from one color to another or if they are born one color and stay that way. Schrichte, however, a reliable observer with years of experience, swears that the trumpetfish he photographed eating the squirrelfish was bright yellow at first, then slowly changed to gray.
A close relative of the trumpetfish is the cornetfish. These fish are easy to distinguish from trumpetfish because they have much thinner bodies, grow to 5 feet long and have a filament trailing from the tail.
You don't have to get wet to see trumpetfish. They are easy to see, hanging vertically like sticks, while strolling among the boats of the Ala Wai Boat Harbor.
Marine science writer Susan Scott's Ocean Watch column
appears Mondays in the Star-Bulletin. Contact her at honu@aloha.net.
