Tag Archives: cornetfish

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.

Maimed cornetfish defies odds with lengthy survival

fish

A cornetfish suffered a severe cut but kept swimming. ©2014 Susan Scott

While snorkeling last week, I came across a 3-foot-long bluespotted cornetfish bitten nearly in half. Amazingly, the severely injured fish was swimming along just fine. Six days later I went snorkeling in the same area and couldn’t believe my eyes. There was the same wounded cornetfish, slower now but still swimming.

That fish had such gumption I wished I could take it to an emergency room and have it sewn up. But as there are no fish hospitals that I know of, I’ll salute that fish by writing about its kind.

One unusual feature of the cornetfish family (four species, two in Hawaii) is that the body is wider across the back than it is deep, meaning from back to belly.

In the bluespotted cornetfish, Hawaii’s most common, snorkelers from above see a long, blue-spotted and blue-lined back several inches wide. In front of the body stretches a long, narrow snout and behind trails a long, streaming tail. (The key word for this fish is “long.”) The tail filament has sensory pores, but no one knows what they sense.

If you alarm a cornetfish, or if it’s stalking prey, the blue spots and lines covering the back turn to dark bars in a kind of plaid pattern that blends well against a pebbly reef floor.

When viewed from the side, cornetfish look like a silver slat, something similar to a side view of an aluminum yardstick. Make that nearly two yardsticks. Including the tail streamer, bluespotted cornetfish grow to over 5 feet long.

Both top-down and side-on camouflage comes in handy for an ambush. The cornetfish can drift toward a fish or shrimp undetected and, with lightning speed, suck the meal into its expandable mouth.

When doing so, the mouth opening flares, resembling the end of a cornet. The brass-horn name also comes from a gooselike honk the fish makes if startled at night.

On Day 7 I couldn’t find my maimed cornetfish and felt relief. I know, of course, that the ocean is one huge fish-eat-fish world, but even so, it’s hard to watch an animal die a long, painful death.

My guess is that a barracuda, common in my snorkeling area, bit the large cornetfish’s back. That the fish escaped and went on to live for a week is a tribute to a remarkable species.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott