Hull Warns Of Lion's Mane Jellyfish Sightings; 'If You Do See One, Exit The Water'

HULL (CBS) -- Unusually large jellyfish are back off the coast of Massachusetts. An official Facebook post in Hull Wednesday warned that sightings of Lion's Mane jellyfish have been reported in the waters surrounding the town.

"It is one of the world's largest jellyfish, with an orange-brown bell which can grow up to 6 feet wide and tentacles that can grow to lengths exceeding 100 feet," Deputy Fire Chief William Frazier wrote.

He said the sting can cause an allergic reaction that might require medical attention.

"If you do see one, exit the water and give it plenty of room to avoid those long stinging tentacles," he said. "If you come upon one washed up on the sand, do not attempt to move it, the tentacles can be very difficult to see and some jellyfish can still sting while out of the water."

A sting victim should remove tentacles using gloves and tweezers - not bare hands. The affected area should be rinsed with warm water and medical attention should be sought if a severe allergic reaction develops.

Last June, Lion's Mane jellyfish began appearing in Massachusetts waters by the tens of thousands. Scientists said they were not really sure about why the jellyfish have started arriving in such large numbers.