The Collaborative International Dictionary of English v.0.48:

Esox \E"sox\, prop. n. [L., a kind of pike.] (Zo["o]l.)
   A genus of fresh-water fishes, including pike and pickerel.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Esox
    n 1: type and only genus of the family Esocidae [syn: Esox,
         genus Esox]