The sheriff of a county maintaining a jail, if a male, shall appoint a competent woman as women’s jailer, who, under the sheriff’s direction, shall have exclusive charge of all female prisoners. The sheriff, if a female, shall appoint a competent man as men’s jailer, who, under the sheriff’s direction, shall have exclusive charge of all male prisoners. Jailers shall hold office during the pleasure of the sheriff and may be removed at any time by the sheriff.