The box-within-a-box (BWB ... Though technically a siphonophore and not a jellyfish, the Man O' War is so closely related that people lump them into the same category. A native of the Atlantic ...

The infamous box jellyfish developed its frighteningly powerful venom to instantly stun or kill prey, like fish and shrimp, so their struggle to escape wouldn’t damage its delicate tentacles.

This remarkable underwater video was captured near the remote island of Palau when a man recorded his "surreal" swim through millions of jellyfish. He was able to do this safely only because the ...

Box jellyfish, Portuguese man-of-war, lion’s mane and sea nettle are among highly venomous jellyfish species whose stings require immediate medical attention, per UF Health. If you experience ...