[Aquatic animals and use of centrifuge in space experiments]

There are some experiments which do not need a centrifuge apparatus in space, however, for other space experiments the use of centrifuge is indispensable as the control. The characteristics of these two types of space experiments are explained. Generally, the more quantitatively the phenomenon is analyzed, the greater the need of centrifuge apparatus becomes. The centrifuge in space can realize various gravity values ranging from 0 to 1 G, and this will extend the present biology to a more universal biology.