Often in the ocean, the giants are gentler than their smaller kin, and to some extent that holds true with the world’s largest jellyfish. Although there have been reports of specimens reaching the same length as a blue whale and weighing up to a ton, serious injury to humans is rare and fatalities rarer still. A major reason for that is because they mainly reside in the chilly waters of the open ocean, so the chances of meeting one while taking a dip are low.
However, they do occasionally drift nearer to land – including the UK – which can cause alarm. But in reality, the greatest risk this jellyfish poses is when it dies: the decomposing body can break up into little pieces that wash up on shore, where the still active stinging cells catch unsuspecting beachgoers unawares.
DANGER FACTOR – Can cause redness and intense pain that has been likened to an electric shock, however the reaction is generally short-lived.
Bell diameter: 2m (7ft)
Tentacle length: < 58m (190ft)