Tag Archives: trumpetfish

Hungry trumpetfish sticks close to turtle at dinnertime

Published May 16, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
A huge trumpetfish rests near the ocean floor, under a turtle that it uses in a kind of symbiosis called commensalism. ©2016Susan Scott

A huge trumpetfish rests near the ocean floor, under a turtle that it uses in a kind of symbiosis called commensalism. ©2016 Susan Scott

While snorkeling last week I thought I saw a remora stuck to the belly of a big turtle.

Remoras are like the family dog standing under the kitchen table waiting for a dropped tidbit, except remoras are lazier. Using the suction cup on top of their heads, remoras, or suckerfish, stick to sharks, dolphins, whales and turtles, getting free food scraps and free rides as well.

The fish swimming closely under the turtle, however, was not a remora, but a huge trumpetfish about 30 inches long. But trumpetfish are not scavengers. They’re ambush predators. In cozying up to the turtle, the trumpetfish was hiding from damselfish nibbling algae and parasites off the turtle’s shell and limbs. When one of the damselfish moved to the side of the turtle, whomp! It was gone, sucked into the trumpetfish’s expanding mouth.

Reef fish eating algae and parasites off turtles is a type of symbiosis called mutualism because both the turtle and the fish mutually benefit. One gets food. The other gets cleaned.

Famous examples of mutualism are cleaner wrasses, 4-inch-long territorial fish dressed in flashy yellow, black and purple stripes. The pattern and colors of these little fish are like neon shop signs advertising the wrasse’s service station.

Fish needing parasite removal or wound debriding come to the site and hold still while the wrasse does its work. Sometimes fish without parasites or wounds visit wrasse cleaners, letting them eat body mucus. This might gain favor with the cleaner wrasse for future visits. Or maybe it just feels good.

Wrasses don’t have a monopoly on the cleaning business. At least 111 fish and dozens of shrimp species eat parasites and tend wounds on fish. In appreciation, barracuda, moray eels, snappers and other predators don’t eat their cleaners.

Still, reef fish should trust no one. A couple of sneakers called saber-toothed blennies mimic the colors and behavior of the cleaner wrasses. When a gullible fish approaches, the blenny sinks its teeth in, getting a chunk of fin or body. The ruse works only on youngsters. Older fish know the con and steer clear of the biting blennies.

My turtle and trumpetfish were engaged not in mutualism, but in another kind of symbiosis, called commensalism. In this relationship, one species benefits (trumpetfish), and the other is neither helped nor harmed (turtle).

Before I left the water, I saw the turtle resting near the bottom, her buddy fish positioned so centrally underneath it looked like the turtle had grown a trumpetfish tail. So cute, those two. I love marine biology more every day.

With friends amid the reef, snorkeling becomes social

Published January 18, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
Trumpetfish

A trumpetfish is counted among the regulars living their lives near a beach along Oahu’s North Shore. ©2015 Susan Scott

While working at Midway, Craig and I made a new friend and invited him to stay with us for a couple of days before he went home to Canada. Because Luke loves snorkeling, and so does Craig’s mother, Claire, visiting from Seattle, we went to my favorite North Shore beach and plunged in.

I know the area well and guided our guests to a turtle spa, where we watched damselfish nibble algae off the turtles’ shells and pluck parasites from their skin. In addition to the usual reef fish, we found a scorpionfish, some marbled shrimp and a yellow-margin moray eel hiding under a rock.

It was a great day, we all agreed, and headed for the beach. But Luke wasn’t done. Calling my name, he motioned for me to come look.

I arrived to find a gray, nearly 3-foot-long trumpetfish standing on its head. The sight is always marvelous, but was even more so because I know that fish. The big predator hangs out near the turtle cleaning station pretending to be a stick. When a gullible fish swims close, the trumpetfish inhales it.

You would think the fish in that area might figure out that that’s no stick in the water, but no. The trumpetfish is huge, healthy and nearly always there.

Cornetfish, close cousins of the trumpetfish, also hang out on that reef. (It has a strong horn section.) Both species have long narrow bodies, but with a notable difference.

From above looking down, and also head-on, trumpetfish look so slim, you can totally miss seeing the fish. But view the same fish from the side and it’s several inches tall, the body broad and beefy.

Cornetfish bodies are the reverse: Their backs are wide enough to be obvious from above, but from the side the fish is flat as a plate and nearly invisible. To further fool their prey, both types can change colors and patterns to blend in with their backgrounds.

Trumpetfish grow about 30 inches long and are like sticks in that they can’t bend their bodies. But cornetfish can. They spring-load their 63-inch-long (maximum length) bodies in an S shape and lunge for their prey.

Trumpetfish and cornetfish are easy to tell apart by their tails. The trumpetfish’s tail is a stubby stalk ending in a fan. The cornetfish’s tail looks like a whip. Both species use the vacuum cleaner method of capture: The fish suck prey into their expandable mouths.

By swimming often in the same place, I recognize some of the undersea locals and consider them friends. As I do 33-year-old Luke and 92-year-old Claire. Snorkeling is a communal ocean sport where neither age nor species matters. What does matter is where you do it.