Warning as rare Portuguese man o' war spotted on Dorset beaches

They use their balloon-like float as a sail to propel them with long tentacles underneath to capture prey with a nasty sting Credit: Sarah Hodgson

Beachgoers are being warned to stay alert after sightings of venomous jellyfish across Dorset's beaches last week.

The Portuguese man o' war has been discovered washed up on a few beaches including Chesil Beach on Thursday 19 January.

These jellyfish usually stay in open water but can get pushed closer to the shore after long spells of strong south-westerly winds.

Sarah Hodgson, from Dorset Wildlife Trust, said: "They turn up most years, usually during the winter period when we typically experience more stormy conditions. 

"Portuguese man o’ war live on the surface of the water using their balloon-like float as a sail, drifting where the wind and currents take them."

These tentacles deliver a nasty and extremely painful sting so stay alert and keep your distance if you happen to spot them in the water. Credit: Sarah Hodgson

The Portuguese man o' war has long tentacles that trail underneath to capture and ensnare their prey.

They can paralyse - and in some cases kill - small organisms but other than delivering an excruciating sting, are not deadly to humans.

Sarah added: "If swimming in an area where Portuguese man o’ war have been spotted in recent days, it would be a good idea to wear a wetsuit for protection. 

"Care should also be taken if they are found washed up on the beach as they still have the capacity to sting, even after they have died, so look but do not touch."