Chiropsalmus quadrumanus
Chiropsalmus quadrumanus, commonly known as the four-handed box jellyfish, is a species of box jellyfish found in the western Atlantic Ocean, the Gulf of Mexico and the Pacific Ocean. The sting is venomous and dangerous to humans, especially children.
Thimble jellyfish
The thimble jellyfish swims constantly by pulsating its bell, rotating as it moves. It forms swarms in warm seas near the surface of the water. Aggregations have been reported covering a million square metres . The jellyfish feeds on plankton, drawing a water current past its outstretched tentacles by pulsating the bell. When edible zooplankton are encountered, they are immobilised by the cnidocytes (stinging cells) and passed by the tentacles to the mouth on the underside of the bell. Thimble jellyfish are consumed by fish, sea turtles and other predators.