At the head of each department there shall be a director. The directors of Finance, Law, and Public Service shall be appointed by the Mayor, subject to the approval of a majority of Council. The Director of Public Utilities shall be appointed subject to the Civil Service provisions of this Charter. The Directors of Finance, Law, and Public Service shall serve until removed by the Mayor, or until their respective successors have been appointed and qualified. Each Department Director shall conduct the affairs of the department as prescribed by the Mayor, and shall be responsible for the conduct of the officers and employees of his department, for the performance of its business, and for the custody and preservation of the books, records, paper, and property under its control. Subject to the supervision and control of the Mayor in all matters, the director of each department shall manage his department. All city department directors shall submit, in a reasonable length of time, information and records of employees as requested by the Civil Service Commission