Box jellyfish
In Australia (mainly northern; however, box jellyfish can live in subtropical waters as far south as Sydney, with "Carybdea marsupialis" being recorded as far south as Bermagui, Sapphire Coast) the highest risk period for the box jellyfish is between October and May, but stings and specimens have been reported all months of the year. Similarly, the highest risk conditions are those with calm water and a light, onshore breeze; however, stings and specimens have been reported in all conditions.
Apolemia uvaria
String jellyfish are colonial animals that may reach 3 m in total length and have a diameter of 2–5 cm. The colony is formed of a central string, bearing groups of pink and white tentacles, which clump together or extend. The whole colony has a gas float at the front and a set of swimming bells. This colonial animal is pelagic and is found in oceans worldwide in midwater. These ocean predators act like drift nets, spreading their tentacles to catch plankton. The tentacles give a painful sting and are best avoided.