"Box jellies (also known as jellyfish) belong to the invertebrate Phylum Cnidaria, a diverse group of stinging animals whose members all possess stinging cells for feeding and protection. Jelly/jellyfish relatives include the sea anemones, corals, and Portuguese man-of- war. The box jellies, or Cubomedusae, are named for the squarish shape of their bell-shaped body. As a group, box jellies are found in shallow tropical seas throughout the Pacific, Indian, and Atlantic Oceans. They generally occur in quiet, shallow waters of protected bays and estuaries, and over sandy-bottomed shorelines, though some species have been reported in the open ocean. Box jellies apparently descend to deeper water during daylight hours, but during summer months, adults are often reported at the surface. The tentacles, well-armed with potent stinging cells can inflict a painful sting on unwary beach goers. An Australian relative, the notorious "sea wasp" box jelly (Chironex fleckeri), is deadly. While the sting of Hawaii's box jellies is not usually lethal, it is reported to be more painful than that of the more common Portuguese man-of-war." (Waikïkï Aquarium Education Department University of Hawai‘i-Mänoa, 2009.)