Moon jellies, which are found in shallow bays around the world, look like small, not entirely friendly ghosts.
They have translucent bells fringed with pale tentacles, and as they pulse along, it almost seems as if the water itself has come alive. At the National Aquarium in Baltimore, when visitors are invited to touch moon jellies, their first reaction is usually fear. Assured the jellies won’t hurt them, the visitors roll up their sleeves and hesitantly reach into the tank.
“They’re squishy!” I hear one boy squeal.