Atolla jellyfish
The body of "Atolla wyvillei" is a bell shape and it has several moderately long tentacles along the bell. The bell is around 20–174 mm in diameter. It also has a single long tentacle called a hypertrophied tentacle. This hypertrophied tentacle has several purposes, including aid in predation and aid in reproduction. These jellyfish do not have a digestive system, a respiratory system, a circulatory system or a central nervous system. Not having a central nervous system means that it lacks a brain.
Jellyfish stings in Australia
Jellyfish stings in Australia can cause pain, paralysis and death for swimmers with exposed skin. Numerous venomous species of jellyfish occur in Australian waters, including the box jellyfish and Irukandji Jellyfish. Box jellyfish are believed to have caused at least 69 deaths since record keeping began in 1883. Although they are commonly mistaken for jellyfish, bluebottles are actually siphonophores.