Monthly Archives: September 2017

Mystery fish is revealed as snapper from Tahiti

Published September 30, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

A Tahitian fish called the blacktail snapper can be found in Hawaii. This fish was found at a Ko Olina lagoon. Courtesy Gary Walden

Reader Gary Walden snorkels most days in Ko Olina Lagoon No. 4 and emailed the following, with a picture: “I cannot find the name of this fish.”

I didn’t know the fish name either, but thought it was probably one of Hawaii’s rascally wrasses. Those reef fish are tricksters to us snorkelers because worldwide there are 460 species in the family, and of those, Hawaii hosts 43.

That might not be so hard to sort out, except that some baby wrasses look so different from their parents that in the past, researchers considered the youngsters separate species and gave them their own scientific names. The true identity of the young wrasses became apparent when they gradually changed into their adult colors.

As if that’s not enough to confuse even seasoned fish watchers, some wrasses change body color dramatically after they’re adults, switching from female to male as the need in a wrasse harem demands.

Since I was feeling a bit under the weather when I received Gary’s email, I carried my fish ID book to the couch, lay back and started paging through wrasse pictures. Nothing, however, popped out resembling the Ko Olina No. 4 fish. Frustrated and sleepy, I tossed the book toward the coffee table where it fell off the edge.

And behold! When I reached down to pick up the guide, there was Gary’s fish staring up at me. The guide had fallen open to the snapper family and lay open on the precise page.

Gary’s fish is called a blacktail, or flametail, snapper, Lutjanus fulvus. The blacktail snapper has no Hawaiian name because it’s a Tahitian fish, not native to Hawaii waters. Tahitians call it to’au.

Hawaii hosts only two native coral reef snappers (we have three deep-water species: opakapaka, ulaula and onaga) and since snappers are delicious, in 1956 state fisheries managers brought blacktails here from Moorea, an island in French Polynesia.

Those snappers were roamers. Only weeks after their release in Kaneohe Bay, anglers caught them in North Shore’s Waimea Bay and others were caught off Honolulu.

To’au never became abundant, however, and in 1958, officials tried again, this time bringing to Hawaii bluestripe snappers, called ta’ape in Tahitian, from the Marquesas.

Although the introduction was well-intended, bringing the 12- to 13-inch-long fish to Hawaii was a mistake. Even though the ta’ape did well in Hawaii waters, and the to’au are hanging in there, they never caught on as food fish. A third introduced species called the paddletail snapper is rare here today.

Even so, Hawaii’s immigrant snappers have their charms, being attractive and — who knew? — psychic too. The next time someone sends me a snapper picture, I’ll just throw my fish book at the wall and let the fish find itself.

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.