Portuguese man-of-war spotted on Kanagawa beach

By Casey Baseel

With just a few weeks left before September, beach lovers in Japan are trying to sneak in a few last trips to the coast. A late summer trip to the shore means you’ll have to be on the lookout for jellyfish, but the good news is they don’t seem to be out in full force yet.

The bad news, though, is that Kanagawa Prefecture has something that looks sort of like a jellyfish but is even worse, with some people having spotted the Portuguese man-of-war. The Portuguese man-of-war is a colony of interdependent marine creatures that band together to survive and look hideous. Usually, it makes small fish its target, paralyzing and then consuming them.

They aren’t regular visitors to Kanagawa, but lastweek Twitter users found specimens washed up onshore in Shonan, the prefecture’s most popular string of beaches and recreational coastline. One was largely buried in the sand at Kamakura’s main beach, Yuigahama, and was only spotted because of its eye-catching blue hue.

As you’d expect from its name, the stings from the man-of-war pack a serious punch. The man-of-war can even continue fighting on dry land from beyond the grave, with its tentacles still potent days after death. Aside from leaving painful red welts on the skin, the creature’s toxins can affect the function of the lymph nodes, as well as the heart and lungs, which in extreme, and thankfully rare, cases can even cause death.

Because the man-of-war looks like a jellyfish, some people’s first reaction is to treat a man-of-war’s sting in the same way by washing the affected area with vinegar. Despite their somewhat similar appearance, though, the man-of-war and jellyfish are completely different creatures with different toxins, and pouring vinegar, or even room temperature fresh water, onto a man-of-war sting will speed up the toxin delivery and make things worse.

Instead, the stung area should be rinsed with salt water, then with water heated to 45 degrees Celsius, which will help to break down the toxins and ease the pain. It seems like a trip to the hospital wouldn’t be a bad idea either.

Source: Jin

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When I was a kid, the lifeguards always kept a bottle of (powdered) steak tenderizer around to deal with man 'o war stings (the creatures are common on Hawaii beaches); apparently the papain found in most tenderizer is effective. Of course, they also used to recommend peeing on the affected area, a remedy which I think has since been debunked.

8 ( +8 / -0 )

Been seeing them a lot recently but yesterday was the first time I've seen three people stung (in the same day) while surfing at Shichirigahama. Keep your eyes open, usually you can see them, if looking. "Knock on wood"

0 ( +0 / -0 )

Ah, false advice here folks! You treat the sting with vinegar! All the lifeguards on beaches in Australia keep large bottles if vinegar on-hand during blue-bottle season (Jan-Feb). DO NOT rub the sting or try to wash off the tentacles. You will only spread the stingers and they are very painful! I grew up surfing on the east coast of Oz and was a surf lifesaver for many years. These little blighters are regular seasonal visitors. I've been nailed by these suckers scores of times and it's not a pleasant experience. The pain goes away quickly when treated with vinegar, but the welts remain itchy for a couple of weeks. I've only ever heard of one case that needed medical attention and that was from a person that had an allergic reaction to them. I've seen them irregularly on the east coast of Japan in Chiba and Ibaraki, but not in the numbers we get them in Oz. If you are going to the beach in Japan during jellyfish season (Sept-Oct) throw a bottle of vinegar in your kit. It also works on other kinds of jellyfish stings as well.

1 ( +4 / -3 )

Tenderizer, urine, and vinegar do nothing for this. I have been stung countless times, as I am a beach bum from Sydney. The worst was when a tentacle wrapped around my arm and I went into anaphylactic shock!! I walked to the chemist who immediately tore open a packet of something and told me to drink it to prevent a heart attack. I had welts and bruises on my arm for about two weeks. Admittedly this was a particular nasty sting but DON'T play around with this. If stung, try to get to a hospital. This may be over reacting but it's better to be safe than sorry. Peace!

7 ( +8 / -1 )

I've seen microscopic video showing the stings in progress. I swear it looked like mini harpoon guns barbs and all, going off.

0 ( +0 / -0 )

According to the NHS, vinegar should not be used on any jellyfish stings at all:

Be wary when getting health info from news sites, blogs etc. Stick with the sites that represent medical professionals.

2 ( +2 / -0 )

Kiss1966 - Are you serious? I've had stings across my face, around my chest, around my arms, even had one go into my board shorts (luckily I was wearing underwear) and most of the stings were 30 odd years ago when people were told to rub sand into them. Stop trying to spread panic! Anaphylactic shock? You must be one of these soft-rooster Sydney-siders!

2 ( +4 / -2 )

I've seen these every summer in Shonan for the past 15 years. Been stung countless times. Vinegar does the trick. The welts take time to heal, though.

NHS just wants people to rely on pharmaceuticals, so bear that in mind.

3 ( +5 / -2 )

@ Disillusioned - I hear ya. Growing up in Sydney involves at least a few attacks of these wretched bluebottles! Almost a rite of passage - along with bindies on the lawn...

0 ( +1 / -1 )

Those little jellyfish can be fiercely stingy. I once had a very beautiful 1 meter long line of small red dots along my right leg, and the pain didn't ease until the next morning. Getting one of those in the face (or eyes) can be life threatening.

1 ( +1 / -0 )

I got stung by a dead one 2 weeks ago (It was painful and little marks are still at my fingers). VINEGAR might do the trick but not recommended in this case. Usually hot water dipping (if possible) is recommended.

0 ( +1 / -1 )

Here's how the folks in Hawaii have learned how to deal with those little devils...

1 ( +1 / -0 )

When I was a kid, we'd yell a swear word, and maybe even get out of the water. Can't remember doing much else. We'd stomp on them if we found them washed up on the beach. (Box jellyfish though, me no touch. Me put in bucket to prove I really saw one)

Some people apparently get really sick though. Sympathies, etc.

Apparently running hot water over the sting is the best. Or ice pack.

Vinegar is discouraged on 3 sites so far...

Heaven forbid anybody confuse me with some delicate flower from NSW but their ambulance site says absolutely no vinegar too. Hmm.

1 ( +1 / -0 )

Yes, the stings hurt. but bluebottles also make a satisfying pop if you jump on them after they have been on the beach a day or 2.

1 ( +1 / -0 )

Kill it with fire!

2 ( +3 / -1 )

For a few seconds I thought Rodrigues sailed the Black Ship through a time warp looking for Anjin-san!

1 ( +1 / -0 )

They announced a frantic 'get out of the water' message at my local beach in Shizuoka yesterday afternoon and the beach crowded with last of summer swimmers was almost empty in 5 minutes. Then the lifeguard was walking around showing the few left at the beach one of these guys she had caught.

0 ( +0 / -0 )

Ah, false advice here folks! You treat the sting with vinegar! All the lifeguards on beaches in Australia keep large bottles if vinegar on-hand during blue-bottle season (Jan-Feb).

How nice of you to identify your advice as "false". Given the choice of lifeguards or peer-reviewed articles in journals, we should ALWAYS believe the lifeguards... None of the references listed in the Wiki entry obviously know what they are talking about because after all, the lifeguards have EXTENSIVE medical training regarding the treatment of marine venom, right?

1 ( +1 / -0 )

Aloe vera soothes the sting for a while, although it doesn't grow near the beaches here in Japan. Unless you have an allergic reaction it should stop hurting in about 30 minutes, so you just need something to stop it hurting for a while.

I've been stung a dozen or so times and it hurts like the blazes for a while. The tricky bit is getting the stinger off you without getting your hand stung. I've had friends "helpfully" try a ton of stuff. Cold water hurts like hell, bicarbonate of soda helped a little, aloe vera worked best in my opinion, about equal to meat tenderizer or warm tea bags.

Little kids get stung regularly and the trick is just to do "something" to keep their minds off the pain until the poison dies down. Given how close hospitals are in Japan its probably best to pop down to the closest one and get them looked over, its normally only 5 to 10 minutes. Back home this just isn't practical, normally the nearest hospital is 30~60 minutes away and by the time you get there the pain is gone.

The problem with these suckers is that they can come in whole swarms, and if you're a surfer or a diver and head into them then you're looking at a world of pain. Wear a good wetsuit and keep a sharp eye out for any water that looks too blue (seriously, this is the best way I can describe it... when there's a whole swarm of them a patch of the ocean looks almost purple-blue and that's normally the only warning you get).

As for swimmers, well, if you see one assume there are more and go find somewhere else to swim.

1 ( +1 / -1 )

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