Reader Sean Goodchild sent this photograph to the Algarve Resident this week.
It was taken on Benagil beach in the Lagoa council, following bad weather in February.
Élio Vicente, a marine biologist from Zoomarine, said: “This specimen is a Portuguese man-of-war (Caravela Portuguesa). They are very common on our shores.”
Commonly mistaken as a jellyfish, the Portuguese man-of-war is a siphonophore, an animal made up of a colony of organisms that work together.
The conjoined organisms get their name from the gas-filled polyp, which sits above the water and resembles an old war ship at full sail.
“The Portuguese man-of-war is very poisonous and people who find them on the beach should not touch them,” said Élio Vicente.
Long thin tentacles, which commonly extend up to 10 metres, are filled with venom used to paralyse and kill fish and other small creatures, and can deliver an excruciating sting to a human.
Man-of-wars are found, sometimes in large groups, floating in warm waters throughout the world’s oceans, where they can be washed ashore by strong winds.