Ó Bradáin
Ó BRADÁIN—I—O Bradane, O Bradan, O Bradden, Bradan, Bradden, and, by 'translation,' Salmon, Sammon, Fisher; 'descendant of Bradán' (diminutive of brádach, spirited; also a salmon); a rather scattered surname. In Co. Roscommon, it seems to have been an alias for Ó Bradagáin, which see. Salmon, as an anglicised form of this surname, dates back to the year 1555; and Salmon, of course, suggested Fisher.
Alphabetical Index to Irish Surnames