About Carybdea marsupialis (Linnaeus, 1758)
Carybdea marsupialis is a small transparent box jellyfish. Its box-shaped bell measures roughly 3 cm (1 in) across; four elongated tentacles, which can grow up to 30 cm (12 in) long, extend from the four lower corners of the bell. The bell is covered in a number of small white or yellowish warts that contain stinging cells. Four rhopalia—sensory structures that hold ocelli—sit near the bell margin, positioned an equal distance apart from each other between the tentacles. This species can be told apart from other similar jellyfish species by the distinctive red banding on its tentacles. Carybdea marsupialis was historically classified as a widespread species found across warm oceans globally. However, taxonomic reviews have determined that nearly all of these recorded populations actually belong to other species within the genus Carybdea. The true Carybdea marsupialis is essentially limited to the Mediterranean Sea, where it is the only known box jellyfish species. It is a pelagic species that occurs in the upper few metres of the sea.
