The spacebound fish, which will each be around the size of a thumb nail, have all been selected from the cichlid family.
Having been placed in aquarium-like containers, the fish will be strapped into an eight-metre long Texus rocket and blasted up to a height of 260-270 kilometres (162-168 miles).
During their journey into space the fish will find themselves in a weightless state for some six minutes.
“Quite simply, they are going to be seasick until they have managed to acclimatize,” said Esrange spokeswoman Johanna Bergström-Roos.
When the fish have come back down to earth, researchers will examine their otolith organs, which are structures used to sense gravity and acceleration.
The thesis put forward by the German researchers behind the project is that the shape of the otoliths may have a bearing on variations in sensitivity to travel sickness.