rotifer

from WordNet (r) 3.0 (2006)

rotifer
    n 1: minute aquatic multicellular organisms having a ciliated
         wheel-like organ for feeding and locomotion; constituents
         of freshwater plankton

from The Collaborative International Dictionary of English v.0.48

Rotifer \Ro"ti*fer\ (?; 277), n. [NL. see {Rotifera}.] (Zool.)
   One of the Rotifera. See Illust. in Appendix.
   [1913 Webster]

[email protected]