The mayor, or the chief executive officer if there is no mayor, of any municipality of this state having a municipal court may appoint a parole board consisting of five members, one of whom he shall designate to serve at his pleasure as chairman, and such chairman, shall if in attendance, preside at all meetings of the board. In the chairman’s absence, an acting chairman shall be selected by a majority of the members present. One member of the initial board shall be appointed to serve a term of six years. Two members of the initial board shall be appointed to serve four-year terms and two members of the initial board shall be appointed to service two-year terms. Thereafter all members of the board shall be appointed for six-year terms.