The Collaborative International Dictionary of English v.0.48:

Marena \Ma*re"na\, n. [NL. Salmo maraena, G. mar[aum]ne,
   mor[aum]ne; -- so called from Lake Morin, in the March of
   Brandenburg, in Prussia.] (Zool.)
   A European whitefish of the genus Coregonus.
   [1913 Webster]