Tag Archives: toxin

Hallucinations from toxin in fish are rare but potent

Published July 23, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
Bandtail goatfish, or weke pueo (sometimes called weke pahulu), are among the fish that can cause hallucinatory fish poisoning. ©2016 Susan Scott

Bandtail goatfish, or weke pueo (sometimes called weke pahulu), are among the fish that can cause hallucinatory fish poisoning. ©2016 Susan Scott

A Kentucky man emailed that he was doing research on nightmare weke and wondered whether I knew of recent cases here. Because I hadn’t written about this odd illness, also called hallucinatory fish poisoning, for years, I wondered, too.

The term nightmare weke makes it sound as if only goatfish carry this poison. But the rare toxin, origin unknown, is found throughout tropical and temperate waters. Other culprits include convict tangs (manini), chubs (nenue), mullets (ama), coral groupers and rabbitfish (the latter two not found in Hawaii).

In the Mediterranean and eastern Atlantic, the common food fish saupe, or sea bream, has caused hallucinatory fish poisoning. In Arabic the sea bream is known as “the fish that makes dreams.”

Reunion Islanders (Indian Ocean) call a rabbitfish “the fish that inebriates.” Hawaiians named the sometimes hallucinatory bandtail goatfish weke pahulu, meaning “king of ghosts.”

“Ghost” is putting it mildly. The visions that afflict people who eat affected fish are so dreadful, I get the creeps reading about them.

In 1994 a 40-year-old executive ate sea bream in Cannes, France. Severe vomiting that night caused the man to shorten his vacation and drive home. Soon he started hearing animals screaming and stopped when giant insects surrounded the car. After 36 hours in the hospital (with sedation, I hope), the man was fine.

Another Frenchman in 2002 ate sea bream he bought from a fish market. Because he was 90 and feared people would declare him senile, the man suffered terrifying hallucinations of humans screaming and birds shrieking. When the visions disappeared he reported the incident.

These report dates from a poison center in Marseilles show that the toxin is rare in France. It’s rare in Hawaii, too. From 1990 to 2014 the number of cases reported to the Department of Health was 17, the last one in 2011.

The unidentified toxin occurs in both carnivores and algae-eaters, usually in summer. Cooking doesn’t inactivate the poison, which seems to be concentrated in the head. One Hawaii blog offers good advice to mullet and goatfish fishers: “No eat da head.”

In a 1960 medical journal, researchers wrote that information about this syndrome was being suppressed because “Russia was exceedingly interested in nerve drugs such as this.”

I learned that my emailer’s research was not a scientific study as I thought. Rather, he was gathering material for a New York friend making a film about substances in nature that get people high.

You know it’s a crazy world when people consider poisoning themselves and others with a fish.

Report hallucinatory fish poisonings to the state Department of Health. Save the fish for testing.

Puffer fish armed with toxin in addition to its spiny body

Published October 5,, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott

A dead ulua, or jack, washed up on Kailua Beach recently after having tried to ingest a porcupine puffer fish, which inflated and stuck in its throat. ©Greg Turnbull

A dead ulua, or jack, washed up on Kailua Beach recently after having tried to ingest a porcupine puffer fish, which inflated and stuck in its throat. ©Greg Turnbull

Kailua resident Greg Turnbull sent a picture of a freshly dead, 36-inch-long fish he found on Kailua Beach during a recent dawn walk. Greg thought the fish was an ulua (jack), and I agree. Although it’s unusual for a big jack to wash up on an Oahu beach, that’s not what drove Greg to take the picture. The gaping ulua had an inflated porcupine puffer fish stuck in its throat.

The puffer fish made a fatal mistake. Swelling up in a predator’s throat is a good ploy to prevent being swallowed, but step two is crucial. The puffer must shrink and run before the suffocated fish washes ashore.

People call the 120 or so species of puffer fish several names — balloon fish, blowfish, globefish, toadfish — all referring to their famous defense: an elastic stomach. When threatened, a puffer engorges its stretchy stomach with water or, if a predator drives the puffer to the surface, air.

Susan holding a puffer fish. Courtesy Craig Thomas

Susan holding a puffer fish. Courtesy Craig Thomas

The idea is to grow too big for a predator’s mouth. If the pursuer has a really big mouth, the puffer sticks in the fish’s throat. Because fish breathe by taking water in the mouth and expelling it out the gills, a throat full of puffer fish is deadly.

Another deadly puffer defense is the ability to store a poison called tetrodotoxin. In the ocean, puffers eat plants and animals that contain naturally occurring bacteria that manufacture tetrodotoxin. By choosing food that doesn’t contain those bacteria, aquaculturists can raise poison-free puffer fish.

Tetrodotoxin is well known for being so potent that a tiny dose can kill a person in minutes. The poison blocks sodium channels in nerves, and when sodium can’t enter a nerve cell, it can’t tell muscles what to do, such as breathe. There’s no antidote to the toxin, but, because it wears off by itself, artificial breathing can save a victim.

Ulua (Jack). Courtesy Russell Gilbert

Ulua (Jack). Courtesy Russell Gilbert

So, I wondered, are jacks immune to tetrodotoxin?

Hard to say. Puffer fish have been found in tiger shark stomachs, and the Internet has pictures of a snapper, frogfish, loggerhead turtle and duck eating a puffer fish, but it’s unstated whether the animals lived or died. What I did learn, however, is that the sodium channels in some snails, crabs and presumably tiger sharks are unaffected by tetrodotoxin.

I also learned in my reading that 19th-century warriors from the Gilbert Islands (today Kiribati) wore what a British explorer in 1847 called “an extraordinary looking apology for a helmet.” The illustration shows a porcupine puffer fish skin on the head of a warrior. Apparently the man mistook a fish for a hat.

Thanks, Greg, for sharing your picture. It’s great food for thought.

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

©2015 Susan Scott


Spanish dancer’s flare, eggs attract many devoted fans

Published July 8, 2013 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2013 Susan Scott

A rose is a rose is a rose — except when it’s the egg cluster of a Spanish dancer.

My recent column about that nudibranch and its roselike eggs generated some inspired email. About the lovely red or pink “flower,” a reader wrote, “I have seen the same thing and it looked like someone cut chiffon rosettes off an old-fashioned dress and glued them to the reef. I couldn’t figure out what in the heck they were. Now I know! Thank you.”

And thank you, Steph­a­nie, for describing so elegantly one of the world’s prettiest clutches of eggs.

Biologists call these flower look-alikes egg ribbons, and they are fastened with remarkable strength to the reef. The nudibranch might attach the eggs with a special glue, or the adhesive quality might be in the stickiness of the gelatinous egg cases. No one knows.

Also remarkable is the concentration of poison in the eggs, which contain more recycled sponge toxin than the nudibranch that laid them. In one lab experiment, researchers ground up the red eggs and fed them to creatures that eat almost anything.The offering were rejected.

Another Honolulu
reader, physician and photographer Russell Gilbert, wondered how the nudibranch
eggs held together, so he took a close-up picture. You can see the individual
eggs (and Russell’s other excellent underwater photos) here.

“After taking this shot,” he wrote, “I realized how the eggs were structured — embedded in sheets in some kind of gel-like material.”

He’s right. Multiple eggs are enclosed in rigid, protective mucus capsules, which stick to each other to form the spiraled ribbon.

Once hatched, free-swimming larvae drift in the plankton, eating tiny plants. When a baby dancer is ready to settle down, it alights on its food, one of several species of sponges.

Depending on which sponge species they’re eating, Spanish dancers are red, pink or orange, sometimes mixed with yellow or white.

Most nudies only crawl, but Spanish dancers get their common name from their ability to swim in midwater, flexing their bodies energetically, their soft edges flaring like the skirts of a flamenco dancer. Most people who see this flamboyant dance become lifetime fans and protectors of Spanish dancers.

Nudibranchs in general are not long-lived, some for only a month. The life span of dancers is about a year.

Occasionally, they beach. A San Francisco reader wondered by email whether returning a grounded one to the water revives them or if the creatures were trying to die.

I don’t know, but since nudibranchs have no eyes, my guess is that groundings are accidents occurring when the creatures get too near the shore break.

At the shoreline I once found a live Spanish dancer larger than my hand and waded, fully clothed, to place the creature on the ocean floor. I don’t know whether the orange beauty survived, but it was worth getting wet to give it a chance.

Spanish dancers and their eggs inspire most everyone who sees them. Maybe Elton John’s tiny dancer was a nudibranch, and Gertrude Stein’s rose its eggs.

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