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*First Place winner in National Federation of Press Women Communications Contest, 2008
*First Place winner Health and Fitness category in New Mexico Press Women Communications Contest, 2008.

Published in Wilderness Medical Society Magazine, Summer 2007

It was near the end of our first dive of the day in the 82-degrees F (26 C) waters off Sipadan Island in Borneo in late March. Five scuba divers hovered at 15 feet (5 meters), performing the required but often boring 3-minute safety stop.

In these seas, safety stops are anything but boring.

Iridescent chromis and parrotfish, yellow and black butterfly fish, darting wrasses and other colorful critters flitter and nibble among plate, staghorn and other sheltering hard coral mounts 20 to 30 feet below (6 to 10 meters). Hovering divers enjoy their antics as their dive computers count down. I was memorizing the markings of a previously unseen butterfly fish when something larger flashed in front of my mask.

It was a yellow margin triggerfish, Pseudobalistes flavimarginatus, about 18-inches (47- centimeters) long, shooting back and forth over a patch of coral about 6 feet (2 meters) away. Cute, I thought. I’ve never seen a triggerfish so active. Usually they’re poking about the corals, looking for mollusks to crunch with their very visible teeth.

Suddenly the triggerfish lunged at one of the divers and nipped at his fin.

The diver, Dieter of Heidelberg, Germany, jerked around. The triggerfish lunged again and again at Dieter’s dangling legs and fins. He later said, “I knew it wasn’t a diver because the hit was hard, not soft, as when you accidentally bump someone.” Dieter kicked at the fish, but it wouldn’t retreat. Instead, it darted swiftly between his legs, nipping at his yellow fins again and again. Corinne, Dieter’s dive buddy, also kicked at the fish but to no avail. Those of us still in the water tried to help but were too far. The lunging fish kept all of us at bay.

Before Dieter could retreat or surface, the triggerfish, mouth wide open, lunged at his bare white right lower leg. It bit Dieter savagely on the calf. Blood gushed from a wound the size of a dime. Dieter grabbed his leg and kicked diagonally to the surface and the waiting boat.

The triggerfish swam back into the coral.

Schooling Triggerfish c. Lanelli 2007

As the rest of the divers surfaced and clambered aboard, they clustered around Dieter, who wasn’t in distress. “Does it hurt? What happened?” they asked.

“I saw it first,” said Corinne. “It was swimming around his head, just out of his view. I tried to kick it away from his head or warn Dieter, but I couldn’t. That’s when it went for his leg.”

Strike, the divemaster, opened the first aid kit, and Dieter, a medical doctor, cleaned his wound with fresh water and alcohol. When the blood was wiped off, three sets of detailed circular bite marks showed just lateral of the mid-shaft tibia. It appeared to be a superficial wound. “It bit me three times, quickly, with its hard mouth.” Dieter pointed to the dime-sized circular bites. “Look, you can see the mark of each individual tooth.”

Dieter and Strike wrapped the bite with a couple of turns of sterile gauze. By now, it had stopped bleeding.

“Look at your fin!” exclaimed Serge, another diver. He held up Dieter’s yellow fin. It bore a small pea-sized hole.

During the hour’s surface interval, we teased Dieter. “Triggerfish like German food,” we joked. “Or pretty legs!”

Dieter smiled good-naturedly.

“You were the only one not wearing a full wetsuit,” I commented. “Maybe the fish was attracted by your bare white leg.” Dieter wore a shortie wetsuit that reached mid-thigh, leaving the legs exposed. The rest of us were encased in black neoprene rubber from neck to ankle. “Then why didn’t it attack his bare head?” Someone else queried. After an hour’s surface interval, Strike announced the next dive. We looked at Dieter. He smiled and announced, “I’m ready to dive again!”

“OK, Dieter, but swim away from us,” we teased. “With that wound, you’ll attract sharks.”

“Don’t worry about the sharks,” he retorted. “Watch out for the vicious triggerfish!”


Divemaster Streisand “Strike” Stephen of Borneo Divers Mabul Resort explains. “Triggerfish nest during periods of the full moon. The females guard the eggs and will attack anything that swims near. Dieter didn’t do anything to provoke the attack; he just happened to be in the wrong place.”

This wasn’t Dieter’s first encounter with nesting triggerfish. “I was attacked two years ago, in the Maldives, about this time of year. I saw the nest and two fish taking care of the eggs, which were 5-10 mm orange balls. When one fish saw me, it attacked my fins but didn’t bite me. The other fish stayed on the nest. I also saw a triggerfish attack a diver around his mask. The diver needed a sewing of the wound at the nose.”

Triggerfish are found in tropical oceans all over the world, including Hawaii where they are called “Humuhumunukunuku- a-apa’a.”

According to Gerry Allen in Marine Fishes of Southeast Asia, triggerfish are so-called because of “a mechanism that locks the first dorsal spine into position by the second dorsal spine…the fish can wedge itself into a rock crevice if threatened….” The fish’s “trigger” can also inflict a painful cut on an animal or human that bites or grabs it in that area. Triggerfish are not venomous.

It was full moon during the entire week I dived Mabul Island and Sipadan Island. I witnessed two more triggerfish protecting their nests. At a different dive site, another yellow margin triggerfish nipped a hole in a diver’s yellow fin; another day, a titan triggerfish (Balistoides viridescens) nipped at another diver’s black fins but did no damage. Titan triggerfish can grow up to 60 cm (2 feet).

Dieter’s wound healed quickly. By the third day, it showed only a little erythema with no edema or signs of infection. He flew back to Germany. Eleven days later, he wrote, “The bites are still black – perhaps necrosis? There is an erythema of 4 cm of diameter.”

So what should divers and snorkelers do?

First, watch the moon. If it’s full, give triggerfish a wide berth, especially if they exhibit unusual behavior. The fish’s usual behavior is to nibble on coral, totally ignoring divers and snorkelers. If instead of eating and ignoring you, they’re facing you or your buddies and darting back and forth, then swim away, keeping your fins between you and them. “The locals on Maldives told me that triggerfish defend a cone-shaped area around and above their nests. So if attacked, they said, dive either down—away from the nest, or swim away on the same level as the nest. Never swim straight up because that’s still ‘in their area within the cone.’”

If attacked during a safety stop, the diver should avoid diving down. Having already rid his body of accumulated nitrogen, the diver should swim away at the same level as the nest and gradually rise to the surface.

Triggerfish are colorful critters to watch and photograph. Continue to enjoy them. But watch the moon. And, consider wearing a full wetsuit and possibly a hood.

Ms. Lanelli is a writer, photographer, scuba diver, retired ski patroller, and world traveler. When she is not circumnavigating the globe, she makes her home in New Mexico.

c. Wilderness Medicine Summer 2007

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