The Ducks picked up goaltender Sebastien Caron and forwards Matt Keith and Chris Durno. All five are playing in the American Hockey League.
St. Jacques, 26, had a goal and eight assists in 25 games with Anaheim's AHL affiliate in Portland. Parenteau, 26, had 15 goals and 13 assists in 28 games with the Pirates.
Caron, who signed with the Blackhawks as a free agent last August, posted a 4-4-0 record with a 4.03 goals-against average in nine games with the AHL's Milwaukee Admirals. The 26-year-old has a 25-47-12 record in 91 career NHL games with Pittsburgh and Chicago.
Keith, 23, went scoreless in two games with the Blackhawks this season and added two goals and eight assists in 19 games with the Admirals.
Durno, 26, had four goals and one assist in 22 games with Milwaukee.