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.
Carybdea marsupialis
"Carybdea marsupialis" was once considered a widespread species found in warm oceans around the world. Taxonomic reviews have shown that most of these are other species in the genus "Carybdea", with the true "C. marsupialis" essentially restricted to the Mediterranean Sea. It is the only box jellyfish in this sea. It is pelagic and is present in the upper few metres of the sea.