Dictionary of Ichthyology  

lucy = a pike (Esox lucius) as used in heraldry. Also spelled lucie.

From Yarrell's "A History of British Fishes", 1836 (the baronial families of Lucie of Cockermouth and Egremont from a window of their hall). Photograph by Brian W. Coad.

Canadian Museum of Nature
www.briancoad.com