These deadly Portuguese man-of-war have been washing up in large numbers on a Brazilian beach.

Hundreds of the marine animals have been spotted on a beach in the municipality of Peruibe in the south-eastern Brazilian state of Sao Paulo over the Christmas period.

No injuries have been reported so far, despite the species packing a potentially deadly sting.

Some residents and tourists have been confusing the new arrivals with plastic bags.

Tourist Anna Seabra, 39, was one of those who spotted the otherworldly blue-and-pink-tinged hydrozoans on local Guarau beach.

She said: “I usually visit my sister here in Peruibe. The men-of-war really scared me because they look like they’re from another planet. I’d never seen them before. I got really freaked out.

“I got up really close to them. I could see them breathing. It’s really crazy. It’s not something you see every day.”

Local biologist Edson Ventura told local media he had never seen so many Portuguese man-of-war in one place at one time.

He believes the strong winds and numerous waves have been responsible for such a large number of the hydrozoans turning up in the area.

He explained: “They don’t swim, they remain on the water’s surface. They have a bubble, full of air, which gives them buoyancy. Their tentacles remain underwater and they follow the ‘taste’ of the wind and current.”

Biologist Eric Comin told local media that the men-of-war were brought by the South Atlantic Central Water mass.

He explained: “This water is rich in nutrients and they come here during this time period, in the spring and summer. The water is a lot colder and there are many cnidaria present, like this animal.”

The Portuguese man-of-war (Physalia physalis) inhabits all tropical oceans. It is named as such for its resemblance to the man-of-war, a 15th century Portuguese warship.

It is considered dangerous, as its tentacles release a substance that can cause third-degree burns, and in extreme cases can sometimes cause cardio-respiratory arrest.

If stung, it is best to apply vinegar to the affected region until proper medical care is obtained.

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