A German scientist is claiming to have proved that fish can become 'seasick'.
Dr Reinhold Hilbig, a zoologist from Stuttgart, studied the effects of weightlessness in water as part of research into how humans are affected in space.
Forty-nine fish in a mini aquarium were sent up in a plane that went into a steep dive, simulating the loss of gravity astronauts encounter in space flight.
He said eight of the fish began turning around and around in circles, reports the Daily Telegraph.
"They completely lost their sense of balance, behaving like humans who get seasick," said Dr. Hilbig.
"The fish lost their orientation, they became completely confused and looked as if they were about to vomit. In the wild such a seasick fish would become prey for others because they are incapable of fleeing from danger."
The eight seasick fish were later culled and their brains examined to try to determine the exact cause of their sickness.
"It would seem the loss of eye contact with water movement and vibrations plays a large part in their disorientation," Dr Hilbig said.