It looks like a curtain of Mardi Gras beads hung in a doorway, but fish should choose another door! These are a Physalia’s (Man-o’-War jelly’s) tentacles hanging beneath its ship-shaped surface float. The “beads” are batteries of stinging cells that inject toxin into any creature they contact. Deadly to small prey, the sting is very painful for humans. (Photo by Larry Madin, Woods Hole Oceanographic Institution)