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.
Crossota millsae
"Crossota millsae" was first described from the Pacific Ocean off Hawaii and California. It was subsequently found in the Arctic Ocean and in Guayanilla Canyon off Puerto Rico. NOAA researchers who filmed this species in 2018 near Puerto Rico called it a "psychedelic" jellyfish. It lives below 1 km depth in all four regions. Its highest abundance is found at 2500 m off California and 1250 m off Hawaii. In the Arctic Ocean, it has been observed sitting on the seafloor.