The mayor shall be superintendent of the department of public affairs and the council shall at the first regular meeting after election of its members designate by a majority vote one councilman to be superintendent of the department of accounts and finances; one to be superintendent of the department of public safety, and one to be superintendent of the department of street and public improvements and one to be superintendent of the department of parks and public property; provided, however, that in cities having a population of less than ten thousand there may be designated to each councilman two of such departments. Such designation shall be changed whenever it appears that the public service would be benefitted thereby. The council shall at such first meeting, or as soon as practicable thereafter, elect by majority vote the following officers: A city clerk, attorney, assessor, treasurer, auditor, civil engineer, city physician, marshal, chief of fire department, market master, street commissioner, and such other officers and assistants as shall be provided for by ordinance and necessary to the proper and efficient conduct of the affairs of the city; provided, however, that only such of the above officers shall be appointed as may in the judgment of the mayor and councilmen be necessary for the proper and efficient transaction of the affairs of the city. Any officer or assistant elected or appointed by the council may be removed from office at any time by a vote of a majority of the members of the council, except as otherwise provided in sections 78.010 to 78.420.