heteronereis

1 definition found

heteronereis - Collaborative International Dictionary of English v.0.48 :

  Heteronereis \Het`e*ro*ne*re"is\, n. [NL. See Hetero-, and
     Nereis.] (Zool.)
     A free-swimming, dimorphic, sexual form of certain species of
     Nereis.
     [1913 Webster]
  
     Note: In this state the head and its appendages are changed
           in form, the eyes become very large; more or less of
           the parapodia are highly modified by the development of
           finlike lobes, and branchial lamell[ae], and their
           set[ae] become longer and bladelike.
           [1913 Webster]