Beachgoers in the UK have been warned after several Portuguese man o' war were spotted on the Cornish coast, including in Sennen, Crantock, and Longrock. One was described as a "monster" by locals.
The creatures, which can grow up to 20 metres long, are known for their painful sting that can cause welts and, in rare cases, deadly allergic reactions. Despite typically inhabiting tropical waters, they have been increasingly found near British shores.
Amanda Duffin reported seeing "massive ones" on Longrock beach near Penzance, warning dog walkers to beware. The NCI St Ives shared a photo on Facebook, advising caution as more may be heading up the coastline.
Portuguese man o' war are not jellyfish but a rarer creature called a 'zooid'. They cannot swim and are carried by currents and winds, often washing up after storms. They can be identified by a distinctive purple float, blue-purple tentacles, and a pink-tipped crest.
Matt Slater of Cornwall Wildlife Trust advised swimmers to avoid them and, if stung, to wash the area with sea water, scrape away tentacles with a credit card, apply hot water, and seek medical advice. Similar warnings were issued in Wales after sightings on Porth Trecastell beach.
