Hey, it’s Kallie from PBS Eons I’m here to talk about some really weird, potentially dangerous colonial critters Sharks, killer whales, pufferfish.

There’s a lot of stuff in  the ocean that can kill you if you aren’t careful. But one of the weirder  threats sailing the seven seas is the Portuguese man o’ war.

These translucent creatures have tentacles that can be 30 meters long, and have a sting powerful enough to cause cardiac arrest or respiratory failure. Luckily, they’re only found  in isolated tropical regions, and aren’t a threat to anyone  not swimming in those waters. Kidding!

They’re spreading. [intro music] To start, let’s break down their biology, because it’s bizarre. You might have heard these  things referred to as jellyfish, and fair enough, they do look like them. But the truth is far weirder.

They’re actually siphonophores. Siphonophores are a group of marine invertebrates that are colonial organisms, where the whole animal is kind of made up of other, smaller animals. Imagine an ant hill that floats, but the ant hill itself is also alive, not just the ants inside it.

That’s a siphonophore, more or less. Like an ant hill, the parts that make up a siphonophore all have specialized roles to play, like organs in a more normal animal. We mostly recognize them from  their gas-filled bladder on top, which is a feature that helps  them drift on the ocean currents, since they rely on wind and  water movements to move around.

Recent research has shown  that the Portuguese man o’ war isn’t a single species. Ocean currents and wind  patterns pose invisible barriers that they can’t cross due to not  being able to move on their own. Over time, they’ve evolved into distinct  species across the world, like animals marooned on different islands.

Many of the siphonophores that we know about are super small and delicate, which also makes them hard to capture and study. So a lot of what we know about this whole group comes from the Portuguese man o’ war, which is among the largest, toughest and most widespread of the group. And not only are they tough, they pack a punch.

A Portuguese man o’ war’s  sting can be really nasty. While stings aren’t usually fatal, the pain from one can last for months afterwards, causing repeat reactions and  persistently blistering skin. In one case, a 46 year old woman reported still feeling pain  from a sting a full year later.

Luckily for those who suffer a sting, fast treatment can usually keep  the worst side effects at bay. You might have heard of a few DIY remedies for treating jellyfish stings, but most of them don’t hold any water. Baking soda won’t help,  shaving cream does nothing, and peeing on the wound  will only make your friends look at you differently, probably forever.

The best quick solution is vinegar,  as strong as you can find - diluting it at all worsens how effective it is. But that’s what to do in the moment. When it comes to long-term treatments for stings, there’s not a ton we know.

While there’s been some research into a drug called verapamil to help treat the cardiac damage, that’s kind of stalled out since,  well, all the test rats died. And if you’re left with skin damage after a sting, there’s a protocol called  extracorporeal shock wave therapy, which has helped one patient with  persistent blisters get better. Until recently, Portuguese man o’ war were primarily  something you had to worry about if you lived in certain tropical regions.

But like I said, they’re spreading. Rising ocean temperatures due to climate change are helping the Portuguese  man o’war increase its range to the waters surrounding the UK  and the east coast of Australia. And climate change isn’t just temperature, it’s weather as well.

It’s caused increases in wind  speeds and changes in ocean currents that in turn help blow the  man o’ war into new locations. Changes in both wind patterns  and ocean temperatures are causing changes in the  man o’ war themselves, too. They’ve been found in northern Japan, in waters previously thought  to be too cold for them, meaning that they’re adapting to new environments.

Like jellyfish, man o’ war have blooms as well. And in the waters around Australia, scientists expect that warmer waters will  cause more frequent and larger blooms. Since any newcomer to an ecosystem  can upset the apple cart, so to speak, we don’t yet know how the man o’ war may affect their new uncharted waters.

Because they eat fish larvae, they’ll probably have an impact  on local fish populations, and they’ll be competing with  local and native predators. There’s also the fact that local authorities now have to deal with the risk of man o’war stings in areas where they historically never occurred. So overall, it’s tricky times ahead as we sail into the uncertain seas of climate change with the man o’war.

They’re a really interesting, weird organism that’s about to get even weirder. So if you start hearing about man  o’war in your local waterways, now you know why. And if you remember just one thing  from this video, just one thing… Use vinegar if you get stung.

Nothing else. [ outro ]