Class Cubozoa

Cubozoans, commonly known as box jellyfish, are a group of exclusively marine cnidarians that have a distinct cube-shaped bell and a dominant medusa stage. Unlike scyphozoans, cubozoans are very strong swimmers and have a well-developed nervous system, allowing for complex movements. Their radial symmetry is typically in multiples of four, with a tentacle extending from each of the four corners, lined with cnidocytes containing nematocysts used to capture small fish and crustaceans. Cubozoans also have rhopalia, at each corner of their bell, containing statocysts and eyes that are capable of making out images. Their gastrovascular cavity has radial canals that distribute nutrients throughout their body, and the mouth is located on the underside of the bell. Their mesoglea provides them with buoyancy, and muscular contractions of the bell allow them swim quickly in any given direction.