A mysterious oceanic barrier is stopping some deep-sea jellyfish in the Arctic from reaching the Atlantic Ocean, a new study has found.
The animals, members of the jellyfish subspecies Botrynema brucei ellinorae, inhabit depths between 3,300 and 6,600 feet (1,000 to 2,000 meters) and can be divided into two groups based on whether individual specimens have a knob on their umbrella-like bell structure.
