Seasick Fish?

Scientists investigating the potential effects of weightlessness on atronauts in zero-gravity environments recently made an interesting – and perhaps surprising? – discovery: fish can get “seasick.”  Not a comfortable prospect for water-borne creatures, certainly, but researches are hoping that the results of their studies will help them understand the way the brain works in environments in which the body struggles to locate itself in three dimensional space.

Around four dozen fish were taken (in their aquarium) up in a plane, and then the plane went into a sharp dive to simulate a gravity-free environment.  Several of the fish apparently became disoriented and started swimming around in circles.  One researcher even commented that it looked like they were “about to vomit,” although that might be a little tough to verify.

Fish generally locate themselves in three-dimensional space using a variety of methods (similar to humans and their own complex vestibular systems), although fish have something called an “otolith,” or “ear stone,” which works in much the way liquid sloshing in our inner ears helps us balance.  The researchers speculated that the seasickness the fish experienced was largely due to water disturbances, vibrations, and loss of visual information; they did not comment on the free-fall effect on the otoliths.