Barrel jellyfish are capable of detecting the direction of ocean currents and swimming against the current. The first proof that any jellyfish could readily determine the direction of ocean currents and react to the currents was discovered by Graeme Hays of Deakin University in Australia.
Hays and colleagues attached global positioning tracking devices to the barrel jellyfish and tracked the movement of individual jellyfish and schools of jellyfish. The researcher found that the barrel jellyfish can detect the direction of an ocean current in open water and has a preference to swim in the direction that is opposite to the current. The jellyfish do not have any visual clues as to the direction of the current or their position in the ocean. Most jelly fish can detect light and see color but the sight organs are not connected to any central nervous system.
The jellyfish is the only known animal that can determine the direction that it needs to go in based on feeling the ocean current according to the new research. The discovery may be part of the explanation of why most jellyfish form large blooms during some seasons. The researchers are looking at other species to determine if the behavior is common to all jellyfish. The aim of the further research is to protect humans from jellyfish stings and to possibly keep jellyfish out of fish nets.
Why barrel jellyfish can detect ocean currents is still unknown. The researchers suggest that the animals may coordinate the shear of the current across their bodies with the magnetic field of the Earth. No vertebrate animal is known to be able to detect ocean currents with their skin alone.
