Puffy toylike fishes aren’t to be played with

Published September 23, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Boxfish are named for their rectangular shape, formed by a rigid shell around the body. Only the fishes’ eyes, fins, mouths and tail are movable. Boxfish ooze a poison to ward off predators. Courtesy Russell Gilbert

My 10-year-old snorkeling friend Darius shouted, “I see a pufferfish!”

He pointed as we swam at Three Tables, part of the Pupukea Marine Life Conservation District.

I looked at the fish.

“That’s called a trunkfish,” I told him.

But neither of us was entirely right, nor was either of us entirely wrong. The swimming suitcase I called a trunkfish gets the heading “Boxfishes and Cowfishes” in my fish textbook, but adds in parentheses, “Also called trunkfish.”

And Darius wasn’t far off in calling the slow-­swimming fish a pufferfish. Trunkfish and pufferfish aren’t from the same family, but they’re kissing cousins.

No fish, though, wants a kiss from a boxfish. Like its pufferfish kin, boxfish carry a toxin so strong it can kill aquarium mates. And if the little boxfish gets really upset, it can exude, from its skin, enough poison in the tank to also kill itself.

Clearly, boxfish didn’t evolve to live in bowls. In the ocean the boxfish’s slippery toxin repels predators but dilutes fast enough in open water to keep the boxfish unharmed.

Boxfish poison isn’t known to kill humans, as does pufferfish poison, but still, I wouldn’t try licking one. Although some people in Asia eat boxfish, the soapy substance the fish ooze is similar to detergent.

Like pufferfish, blue-ringed octopuses, poison arrow frogs and others, boxfish hire out their chemical weapon production to bacteria. In this classic case of symbiosis, the bacteria get a place to hang their hats, and in return they manufacture sudsy slime to protect their host.

The name boxfish, and trunkfish, comes from the fishes’ rigid, rectangular shell, which covers the entire body like a knight’s armor. Only the fishes’ eyes, fins, mouths and tail are movable. A few bones support the fishes’ internal organs, but evolution has done away with most bones, including ribs.

Hawaii hosts two common species of trunkfish, the spotted boxfish and the thornback cowfish, growing 5 to 6 inches long. It seems as if there are more, because males and females of the same species look different.

The cowfish gets its name from forward-pointing “horns” on its head. When threatened, the cowfish swims backward, keeping its sharp horns facing the intruder. En guard!

Boxfish swim like little wind-up toys, propelling themselves around with amazing speed and dexterity using only side and rear fins. Members of this family eat algae, sponges, worms and small crustaceans.

I don’t fuss over animal names because, to me, as long as the person involved knows what the other person is talking about, well, the name did the job.

I’m looking forward to my next snorkeling excursion with Darius, hoping he spots another pufferfish-trunkfish-boxfish-cowfish. When you see a fish in shining armor, it’s always worth a shout.

Male Spotted Boxfish. Courtesy Scott R. Davis

Female Spotted Boxfish. Courtesy Scott R. Davis

Scorpionfish well hidden with leafy camouflage

Published September 16, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Leaf scorpionfish belong to the scorpionfish family but lack the anglers and venom that others commonly have. Hawaii is home to many leaf scorpionfish, which resemble decomposing leaves drifting in the water. ©2017 Susan Scott

I have a friend named Oakley, and when he emailed, my spam blocker apparently thought he was trying to sell me sunglasses. That’s why just last week I found in my junk mail the note Oakley sent in early August.

“We saw a pair of leaf scorpionfish at 3 tables,” he wrote. “At least I’m pretty sure that’s what they were based on my Googling. Really cool. I thought of you. Is this something common in Hawaii? Never saw one before.”

They are really cool, and yes, leaf scorpionfish are common in Hawaii, sometimes in water only inches deep. But that doesn’t mean we commonly see them. Most people don’t notice them, because they look like their namesake: a leaf. Oakley writes that the two he saw were black and looked like dead leaves drifting.

I’ve surely missed seeing countless leaf scorpionfish during my snorkeling excursions, because camouflage is their (and most scorpionfishes’) defense. But I did spot one several years ago on the North Shore.

Courtesy Russell Gilbert

I thought it was a yellowing leaf until I noticed that it didn’t move as it should when a wave passed in the 3-foot-deep water. When I looked closer, I saw a starry eye staring back at me and knew I had a treasure.

Leaf scorpionfish belong to a large family called scorpionfish, notorious for poking anglers, waders and aquarists with the fishes’ sharp back and side fins. The stings are memorable because many of the world’s 350 species are packing. Venom flows into the victim from glands at the base of the fins’ spines. Leaf scorpionfish have no such venom.

Hawaii hosts 28 kinds of scorpionfish, 11 found only in our waters. Leaf scorpionfish, though, are widespread throughout the Indian and Pacific oceans.

In most places, finding a leaf scorpionfish is a rare event, but not so in Hawaii. Look carefully, though. The longest these little beauties get is 4 inches, but most are only 2 inches.

Besides looking like decomposing leaves (the fish can be white, pink, red, yellow, black, brown, green or mottled), leaf scorpionfish are hard to spot because they collect tiny bits of algae and other marine growth on their skin.

Courtesy Russell Gilbert

When the outfit becomes burdensome, the fish molts. Shedding can occur up to twice a month and starts at the head. In less than a minute, the little leaf-fish is back to its true skin color and starts trying on new accessories.

My yellow leaf scorpionfish held still for pictures, but even when I caused it to hop, it always kept its face inward toward its coral head. This typical head-in pose of the species serves as another defense strategy.

I thanked Oakley for writing, and we made a promise to go snorkeling together soon before the north swell starts up.

I ordered sunglasses from him, too, but I’m still waiting.

Disturbing truth makes seafood unappealing

Published September 9, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

An Australian slipper lobster known as a Balmain bug. ©2017 Susan Scott

Last week when our Sydney taxi driver asked the carload of us where we were from, we shouted in unison, “Bangladesh! France! Guatemala! Hawaii!” We were in Australia attending a wedding, the groom Bangladeshi, the bride French-Guatemalan.

One of the places the French wanted to visit the following week was the Sydney Fish Market, a shore-side facility famous for artful displays of edible marine animals. Many are still alive, the bride told me. You choose something and they cook it for you. Given my interest in marine biology, she was sure I would want to go.

Oh, dear. This brought up my dilemma regarding marine life. It feels wrong to eat the animals that give me so much pleasure when I see them alive in their natural environments.

Seeing them suffocating in tiny tanks and twitching on beds of ice makes my stomach hurt. Plus, I’m aware of stock depletion, habitat destruction and the wasteful ways we catch fish.

On the other hand, it feels equally wrong not to eat marine life that someone, whose livelihood depends on fishing, has already caught. And then there are the markets and restaurants whose owners and employees earn their livings by cooking and selling fish.

According to Sylvia Earle, an oceanographer who has spent more than 50 years working to save the world’s oceans, we who have choices should stop eating all marine animals.

I can practically hear the gasps from island residents, where catching and eating fish, lobster, shrimp and crab is part of daily life. But Sylvia isn’t a fanatic. She’s a scientist who knows the data.

Factory ships put out enormous nets and lines 50 or 60 miles long, and bottom trawlers scoop up entire ecosystems. Humans’ ability to kill wildlife has far surpassed the oceans’ ability to keep up. Even more disturbing is that much of what’s caught is thrown out.

Many people think that marine animals’ sole purpose in existing is to feed us. Not so. Their roles in ocean ecosystems far outweigh our need to eat them.

This wedding, where people of several races came together to celebrate the union of two people from different cultures, was a good example of a changing world. With 7 billion people on the planet, and the oceans in trouble, I’m changing, too. I’m not a vegetarian, but more and more I’m choosing to eat plants over animals.

Except for my visit with those special friends at the Sydney Fish Market. I ordered eel because it was already dead. I had recently written about it. (I didn’t like it.)

The bride picked a slipper lobster known as a Balmain bug. When she passed me her plate for a taste, a silver gull swooped down, snatched the entire lobster tail and flew off with it.

Fair enough, I thought. Seabirds don’t have many choices.

Fortunately, we Americans do.

Nightmare on kid’s feet is critters’ big moment

Published September 2, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Lysianassoid amphipods, above, created an internet sensation when they nibbled on a teen’s feet in the waters at an Australian beach last month. The crustaceans known as sand fleas or sea lice are recyclers of the seas, usually choosing to feast upon dead plants and animals. Courtesy Wikimedia

Bloody attack! Mysterious sea creatures! A taste for human flesh! Unstoppable bleeding … And so went the sensational terms describing an injury sustained by a 16-year-old Australian boy last month.

Having sore leg muscles after a football game, Sam stood with his ankles in the water off a southern Australian beach. The 60-degree water numbed the teen’s skin, and when he emerged, blood oozed from multiple tiny bites.

When the teen’s father posted gory pictures of his son’s feet on Facebook, people got so overly excited you would have thought the kid got shredded by Freddie Kruger. In fact, the 16-year-old had pinprick lesions from a bunch of amphipods just doing their job.

Amphipods are crustaceans, an enormous group of shelled animals including shrimp, lobsters, crabs, barnacles and more. The ocean hosts 8,000 amphipod species with 2,000 more living in brackish and fresh water. Amphipod relatives are isopods and copepods, also with thousands of species each.

In biology, “pod” means feet, and the various prefixes above describe differences in the creatures’ limbs.

Although fleas and lice are insects, and amphipods are not, people often call amphipods sand fleas or sea lice.

The average amphipod is about a half-inch long. Some species, though, are barely visible to the naked eye, and one rare deep-sea species grows to 13 inches.

One of these huge amphipods, appropriately named gigantea, was found in the stomach of a black-footed albatross, one of Hawaii’s seabirds. Researchers believed the huge amphipod was already dead when the bird ate it. Check out this colossal crustacean at goo.gl/XdLhKF.

Most amphipods swim the world’s oceans eating dead plants and animals, making them outstanding recyclers. So, yes, amphipods eat animal flesh, but the creatures are neither parasites nor carnivores. Rather, most are omnivores, eating whatever they find, such as the Australian teen’s feet and ankles.

Sam’s immobility attracted his neighborhood amphipods, and since he couldn’t feel their nips in the cold water, he allowed them to keep biting.

Most amphipods use claw-tipped front legs to eat, cutting food off in tiny pieces and delivering it to the mouth. The creatures have no venom and are not medically dangerous. Had the parents elevated Sam’s feet and put a bit of pressure on the lesions, the bleeding would have stopped. But then the oceans’ sanitation engineers known as amphipods wouldn’t have had their 15 minutes of fame.

An Australian biologist identified the animals that munched on the boy’s feet as lysianassoid amphipods, a family that specializes in recycling. Some reporters, however, erroneously placed the creatures in the Kruger family of Elm Street.

Eagle ray finds a way to soar on minus snout

Published August 26, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

A reader named Pat Goding and her West Oahu snorkeling group have become
acquainted with a spotted eagle ray that has adjusted to life without its food-finding snout,
which has been replaced by a hook. Dubbed Puggy, the plucky ray has
an unusual five stingers on its tail. Courtesy Pat Goding

Last week reader Pat Goding sent several photos of a spotted eagle ray with its snout missing. Part of what looks like a hook protrudes from the ray’s mouth below, and another metal piece sticks up, below the eyes, like a protruding tooth.

But this is not a sad story. It’s the second summer Pat and her snorkeling companions, who call themselves “The West Oahu Swim Posse,” have seen the ray. The plucky fish survived and learned how to live with its disability.

Hawaii hosts only one of the world’s several species of eagle rays. Ours grow 6 feet wide, wingtip to wingtip, with a whiplike tail up to 18 feet long. Eagle rays occasionally cheat death with those long tails. It’s common to see ray tails of various lengths with some even bent, apparently grabbed by their main predators, sharks.

Of all rays, only eagles have more than one stinger on their tails. Some individuals have just one of these defense-only weapons, but others carry up to six. Pat’s flat-faced friend has five.

Six venomous stingers look scary, but we swimmers don’t have to worry about stepping on an eagle ray. Rather than lying on the ocean floor like sting rays, eagle rays rest in a home space, swimming slowly in midwater or near the surface usually in groups of four to six. At mealtime the rays commute to deeper water to dig up some dinner.

Eagle rays have ducklike snouts that jut from below the eyes. Unlike bird beaks, though, the eagle ray’s snout is solid muscle and doesn’t open.

The fish’s mouth is below and behind the snout. Check out a normal eagle ray’s face by clicking on the image below.Arkive species - Spotted eagle ray (Aetobatus narinari)

An eagle ray’s snout is for burrowing. Spotted eagle rays find snails and other shelled animals to eat by plowing their snouts through sand. The cloudy water this creates attracts groupie fish hoping to nab a fleeing shrimp or bolting crab.

Watching an eagle ray dig is a breathtaking sight, as is seeing a squadron of these fish flying through the water in synchrony. Eagle rays are fairly common in Hawaii’s waters. I’ve even seen them in the Ala Wai Boat Harbor.

To swim, eagle rays flap their pointed, triangular fins like wings, causing someone long ago to name them after the regal eagles. Ancient Hawaiians noted the rays’ elegance by calling them hihimanu, meaning magnificent. Pat named the flat-faced ray Puggy, after her much-loved pug dog.

About the ray’s ordeal, it seems its hook wounds got infected, the flesh fell away and the snout healed flat. I didn’t think an eagle ray could live without its food-finding snout, but this one seems to be getting by just fine.

Few maimed eagle rays still fly like an eagle or look cute as a puppy, but Puggy Ray is pulling it off. This hihimanu is a magnificent fish indeed.

Spotted Eagle Ray, Mexico. ©2012 Scott R. Davis

Grotesque acorn worm helps clean sand in sea

Published August 19, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

An acorn worm leaves behind a mound of expelled sand that it has ingested while looking for organic matter. ©2017 Susan Scott

My nephew, Joe, pointed out an area of exposed sand during a low-tide walk in Australia.

“There sure is a lot of poop here,” he said.

“These piles aren’t poop,” I said, of the squiggly pyramids at our feet. “They’re sand cleaned by acorn worms.”

“What are acorn worms?”

“I would have to kill one to show you.”

I wasn’t joking. An acorn worm’s skin is so thin that when it’s full of sand, which is nearly always, the creature bursts open if you pick it up.

Besides, acorn worms aren’t exactly cute and cuddly. Each of the 70 or so species in the world’s oceans looks like a slimy piece of intestine with an acorn for a head and a neck that looks like a cervical collar, the brace people wear for neck injuries.

But even if these marine creatures won’t win any beauty contests, they’re tops in talent. The mushy housekeepers live under the surface from the shoreline to 10,000 feet, cleaning up the ocean’s organic wastes. The worms suck in sand, pick out and eat dead plant and animal material there and discharge the filtered sand in distinctive coils.

Hawaii’s acorn worms grow 1 to 18 inches long, the longer with a body diameter of 1 inch. North Carolina hosts the giant of the U.S., a worm that grows to 8 feet long and digs burrows nearly 10 feet long. The species ranges to Brazil.

An acorn worm’s rounded, muscular head does the digging. The collar serves as an anchor, and the body trails behind. Both head and collar contain glands that produce slick mucus that helps the worm slip through sand and mud.


Other glands make bromine, a chemical with a medicinal smell. This, along with the accumulation of iodine in the body, might protect the worm from infection and/or predators. Given that these slow-moving worms have no teeth or claws, chemicals are their only defense.

In Hawaii, Gould’s auger snail eats only acorn worms. The worm-eating livid cone snail preys on acorn worms.

An acorn worm has no brain, but some nerves. Sensory cells on the head can taste incoming particles. The mouth lies at the junction of the head and collar, and when the worm meets something inedible, it ducks its head into the collar. This closes the mouth like a plug in a drain.

The anus is where you’d expect, on the rear end.

As we walked among the endless acorn worm castings of Queensland’s Pancake Creek, Joe said, “The worms push the sand out from where?”

“From their anuses,” I said.

“Um, Aunt Susan? That’s what people call poop.”

Technically, he’s right. The mounds, called fecal casts, contain the worm’s feces. Still, those are minuscule compared with what was in the sand when the worm ingested it. Call the acorn worm’s sand coils what you will. Given my fondness for marine worms, I call them cool.

Asia market far extends American eel’s journey

Published August 12, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

It’s easy to see why harmless snake eels, such as this one, are mistaken for sea snakes. All eels are fish. ©2017 Susan Scott

I thought I knew my eels, but a recent news item in this newspaper, about a species called the American eel, left me blank.

The story was about the East Coast’s immature American eels, called elvers, wiggly little fish that are fetching up to $2,000 a pound, live, due to Asian aquaculture demands. Managers worry that such demand is jeopardizing the species.

Were baby eels named after elves? I wondered. Alas, no. The word is a merge of the 17th-century expression “eel fare,” meaning (at the time) eel journey.

The fish were well named.

As adults, American eels live in rivers, estuaries or marine coastal areas, eating insects, fish, fish eggs, crabs, worms, clams, frogs and dead animal matter, all at night. In the daytime, eels hide under rocks and logs.

Females grow to a whopping 5 feet long, and males to 3. Individuals live 15 to 20 years.

Old age for the American eel’s life is far from laid-back. When its biological clock sounds the alarm, the fish stops eating, its eyes double in size and the eel ships to sea.

This fish can breathe through its skin as well as its gills, allowing the eel to slink across wet grass and slither through mud. Mucous glands produce slime over the entire body, making the creature, well, slippery as an eel.

The eel’s destination is the Atlantic Ocean’s Sargasso Sea, a 2 million-square-mile area of warm water about 2,000 miles offshore.

It’s a one-way trip. Once there, each female releases 20 to 30 million eggs as males release sperm. Mission accomplished, the adults die.

Hatched eel eggs drift in the Gulf Stream for a year. When they reach the American coast, the transparent juveniles, 2 to 3 inches long, are called glass eels.

As the little fish head toward estuaries, swim up rivers and settle into coastlines, they turn gray-green. These 4-inchers, called elvers, are what Asian aquaculture farmers want for stock in a lucrative market for eels as food.

The American eel is the only freshwater species in North America, but Europe has a similar one, as does Japan. Dwindling stocks of those species have created poaching of American elvers along the U.S. East Coast.

Hawaii has no freshwater eels, but the reefs around us host so many marine species (42 morays, 12 congers and 17 snake eels) that I keep a separate email file just for “sea snake” sightings.

So far, only two were correct, both the yellow-bellied species that occasionally (but rarely) drifts our way on El Nino currents.

Photos are crucial for ID. A reader recently wrote, “I know you don’t think we have sea snakes in Hawaii, but believe me, I know my eels.” The blurry photo he sent was a snowflake moray.

Snowflake Moray Eel, Hanauma Bay. ©2006 Scott R Davis

That golden time of year has arrived on kolea wings

Published August 5, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

A Pacific golden plover, or kolea, pauses on Sand Island, Midway. The atoll is about 1,000 miles from the main Hawaiian Islands, to where the birds migrate from Alaska. Courtesy Luke Halpin

Writing in all caps with multiple exclamation marks is the text equivalent of shouting. But those punctuation points and uppercase letters have their moments, and here’s one: OUR KOLEA ARE BACK!!!

The birds have been trickling in all week, returning from their child-rearing chores in Alaska.

On July 25, Pacific golden plover expert Wally Johnson forwarded me an email with the subject “Plover at BYUH.” Wally wrote, “They’re starting to head back — neat! The early ones in ‘fall’ are often females, as this one appears to be. They apparently leave the guys in charge of their growing kids and zip off to enjoy the less complicated life in Hawaii. So, the cycle is turning once again — amazing.”

The next day, Niu Valley resident Peter Ehrman emailed, “This evening I spotted a kolea in the back of the valley! Don’t know if it’s a very early arriver or a straggler that never left, but it’s definitely a kolea. Thought you’d like to know.”

I do want to know. It’s an exciting end-of-summer moment when we see a plover, and especially exciting when the individual that lives on our lawn or pecks on our street returns.

Just about everything regarding these birds is remarkable, but the one fact that drops all jaws is that each season’s chicks instinctively head south by themselves. They have no guidance besides the compass in their DNA.

Chicks stay in Alaska as long as the tundra still has bugs and berries. The youngsters need to build up enough body fat to make the 3,000-mile nonstop journey to the Hawaiian Islands.

Look for these skinny youngsters in October. If the snow falls late, some chicks arrive as late as November.

It’s a rough trip for a bird that just got its wings, and making it to Hawaii is no guarantee for survival. The young must compete for grazing space with older birds, many of which guard their foraging territory aggressively.

At best about 20 percent of summer chicks live through their first year. On a more cheerful note, the ones that make it through their first year have good potential for a long and healthy life.

When I told my husband about the two plover emails I received, he asked whether I was going to write about these early-­bird arrivals.

Of course. Announcing the return to Oahu of our Pacific golden plovers is an honor I hold dear.

As another reader wrote about hearing and seeing a kolea on her neighbor’s rooftop July 26: “All is right with the world. The kolea are home.”

Thank you to all who wrote about the return of these marvelous migratory shorebirds. We may not be actually shouting, but we’re thinking it. WELCOME HOME, KOLEA!!

People love turtles; it’s pretty easy to see why

Published July 29, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Turtles, with the green ones referred to locally as honu in Hawaiian, are a species of wild animals that are comfortable in the presence of humans. A young turtle barely lifted her head as her photo was snapped and immediately drifted off to sleep. ©2017 Susan Scott

While sitting in traffic last weekend off the North Shore’s Laniakea, one of our green turtles’ favorite hangouts, I saw a young woman sitting cross-legged inches from an enormous turtle. Greens, called honu in Hawaiian, grow to 4 feet long and weigh 400 pounds, and this one was close to the max.

Both creature and person had their eyes shut, the turtle sleeping, the woman meditating. As I watched this peaceful moment between wild animal and human being, I wondered for the zillionth time: What is it about sea turtles that touches so many of us so deeply?

Our love affair begins in the dark, when turtle hatchlings burst from their sand nests like a box of wind-up toys. How we root for the little darlings as they scurry down the beach, the lucky ones dodging crabs, birds and fish that view baby turtles as food. Only 1 in 1,000 hatchlings makes it to adulthood.

As they grow, sea turtle shells turn into 13 little murals called scutes, radiating orange, yellow, brown, black and white. (The green of the name is the color of their body fat.) Sea turtle shells are so lovely that before international trade in so-called tortoiseshell was banned in the 1970s, people made jewelry, combs and endless other decorative items from turtle shells.

Palau women once shaped hawksbill turtle shells into shallow bowls called toluk and used them as money.

Besides admiring their designer jackets, we also love to watch turtles fly. Those long, strong flippers push those bulky bodies through the water with the grace of a deer.

Other wild animals possess poise and beauty, of course, but Hawaii’s honu have another quality that endears them to us like few other creatures: They don’t fear us.

Since gaining protection 44 years ago, green turtles have learned to accept people as part of the scenery. We swim next to them on the reef, glide past them on our surfboards and stand talking, pointing and clicking while they nap.

Even when human admirers swarm, as they tend to do at Laniakea, the turtles remain unruffled. As a researcher once told me when I worried about the crowds, “If the turtles didn’t like it, they wouldn’t come back.”

No law specifies the minimum distance people can approach a sea turtle, but both the National Oceanic and Atmospheric Administration and state Department of Land and Natural Resources recommend that swimmers and beachgoers stay at least 10 feet away.

You can help our honu by reporting harassment or injury to one of these two turtle rescue phone numbers: Weekday days: 725-5730. All other hours: 286-4377. For quick access, I have them in my contacts.

As I watched the meditating woman and slumbering turtle, I remembered a comment a Laniakea visitor wrote in a turtle guest book. Of course, we humans love sea turtles. They are “angels of the sea.”

Pulsating pyrosome lights up dive in Galapagos

Published July 22, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Smaller versions of pyrosome creatures, pictured, are popping up along the Northwest Coast this summer. ©2017 Susan Scott

Years ago, when I was new to marine biology, I booked a dive trip in the Galapagos Islands. Being a novice scuba diver, it took a while to get geared up for my first dive, and I was the last to jump off the boat. I descended, alone, with visions of hammerhead sharks, marine iguanas and other fantastic creatures that made these islands famous.

Instead, I saw something beyond my imagination. An open-ended cylinder about 2 feet long and 6 inches in diameter pulsed before me in the water column, flashing brilliant blue-white light. It was like swimming with an enchanted light fixture.

I had the good fortune to have crossed paths with a pyrosome.

Pyrosomes have been in the news this summer because masses of them are, for the first time, showing up along North America’s northwestern coast. No one knows why the strobing creatures have multiplied to such numbers, why they’re off the West Coast or whether we’ll ever see such a phenomenon again. Only the creatures know what’s happening, and they aren’t talking.

Ten species of pyrosomes pulse throughout the world’s oceans, each in the shape of a hollow tube. The difference between the species is size. The smallest grow only a few inches long. The ones off the West Coast are about 8 inches long and have the cute nickname of sea pickles.

There’s no canning jar, however, that could hold the biggest pyrosomes. They grow to 60 feet, as long as a six-story building is tall.

A pyrosome cylinder consists of thousands of tiny identical bodies, each held in position mouth-sides out, rear-ends in, by the tube’s mucus wall. Each clone sucks in outside water, eating its plankton and breathing its oxygen. The depleted water exits the rears inside, creating a current that propels the cylinder through the water.

Pyrosomes are famous for light flashes created by bacteria in each of the body’s two light organs. (“Pyro” is Greek for fire; “soma,” for body.) When a colony runs into a solid object or polluted water, individuals sparkle, a warning signal to neighbors, which pass it on. An alert results in waves of light that might frighten away a predator.

The following theory about pyrosomes has implications that should give us all stomachaches: Although impossible to prove, it’s possible that reports of a 1964 torpedo attack in the Gulf of Tonkin, which escalated U.S. involvement in Vietnam, may have been the flash of harmless pyrosomes. The creatures are common in that area.

During that Galapagos dive I had no idea what a pyrosome was, and, being separated from my guide and fellow divers, the encounter gave me a jolt of fear. Today the memory gives me a jolt of joy. I got to swim with a living, breathing crystal chandelier.