I*m pretty sure this is a sea nettle but not sure of its territory. The sting of the sea nettle is not usually dangerous to humans, though it can be painful. That pattern is gorgeous, causing some divers wanting to pet it (while fully protected by a wet suit, gloves and socks). Another outstanding place to see aquatic creatures is the Shedd Aquarium in Chicago, on the shore of Lake Michigan, just east of the Museum of Natural History.
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