Beware the Bizarre Blue and Pink Balloon Things on the Beach

Keep away from these animals whose stings still pack a punch after they've died.

Portuguese Man-o-War washed up on a beach

arinahabich / Getty Images 

They are undeniably beautiful, what with their translucent air bags and vivid hues of blue, purple and pink; but the aptly named Portuguese man o' war's enticing look should act more as a warning than an invitation.

What Is the Man o' War?

While often assumed to be a jellyfish, the man o' war (Physalia physalis) is actually a siphonophore—a wonderfully weird animal that is comprised of a colony of clones with various forms and functions, all working in concert, explains NOAA. Named for the uppermost body part, a gas-filled float which sits above the water and looks like a centuries-old warship at full sail, it is also this float that catches the wind and propels them along the water. Unfortunately, other than inflating and deflating, they don't have much agility in navigating and all too often end up being blown onto shore.

Why Is It Dangerous?

Olaf Gradin / Flickr / CC BY-SA 2.0

The problem for beachcombers resides in P. physalis' tentacles, which range from 30 to 165 feet in length. According to NOAA, the tentacles contain stinging nematocysts, "microscopic capsules loaded with coiled, barbed tubes that deliver venom capable of paralyzing and killing small fish and crustaceans." While the man o’ war’s sting is rarely deadly to people, it packs a painful punch and causes welts on exposed skin, they note. And the venom remains active even after the animal has died.

The U.S. National Library of Medicine lists the symptoms of a sting as such:

• Abdominal pain
• Changes in pulse
• Chest pain
• Collapse
• Headache
• Muscle pain and muscle spasms
• Numbness and weakness
• Pain in the arms or legs
• Raised red spot where stung
• Runny nose and watery eyes
• Swallowing difficulty
• Sweating

So now you know. The candy-colored alien creature is not a piece of trash, it's not a toy, and it's definitely not harmless! If you see one, alert the lifeguard and whatever you do, don't try to pick it up.