The Collaborative International Dictionary of English v.0.48:

Vendace \Ven"dace\, n. (Zool.)
   A European lake whitefish (Coregonus Willughbii, or
   Coregonus Vandesius) native of certain lakes in Scotland
   and England. It is regarded as a delicate food fish. Called
   also vendis.
   [1913 Webster]