Honolulu Zoo Director Jeffrey Mahon announced last week that he is resigning, less than six months after starting the job.

Mahon cited personal reasons, city officials said. His last day is Jan. 11. Assistant director Baird Fleming will serve as acting director until a successor is picked.

Mahon, 53, was named zoo director in July 2012. He has extensive background working at aquariums and other underwater facilities.

Mahon was chosen from a field of 40 after former director Manuel Mollinedo resigned effective March 1. Mollinedo cited personal reasons.