In a two dimensional fluid, there are only two classes of swimming way
s of micro-organisms, i.e., ciliated and flagellated motions. Towards
understanding of this fact, we analyze the swimming problem by using w
(1+infinity) and/or W-1+infinity algebras. In the study of the relatio
nship between these two algebras, there appear wave functions expressi
ng the shape of microorganisms. In order to construct well-defined qua
ntum mechanics based on W-1+infinity algebra and wave functions, essen
tially only two different kinds of definitions are allowed for the her
mitian conjugate and the inner products of the wave functions. These t
wo definitions are related with the shapes of ciliates and flagellates
. The formulation proposed in this paper using W-1+infinity algebra an
d wave functions is quantum mechanics of fluid dynamics where the stre
am function plays the role of the Hamiltonian. We also consider the ar
ea-preserving algebras which arise in the swimming problem of micro-or
ganisms in a two dimensional fluid. These algebras are larger than the
usual w(1+infinity) and W-1+infinity algebras. We give a free field r
epresentation of this extended W-1+infinity algebra.