The mayor of Alexandria and a state senator from that city on Thursday joined the already crowded field of Democrats vying to succeed retiring U.S. Rep. James Moran.

Mayor William D. Euille and Sen. Adam P. Ebbin separately announced that they were joining the race to represent Arlington, Alexandria, Falls Church and part of Fairfax County.

“I’m in!” Euille said in an e-mail sent to supporters early Thursday. “I wanted to let you know that I am running for the Democratic nomination for the Eight Congressional District to replace my friend and a great public servant, Congressman Jim Moran.”

By early afternoon, Ebbin was out with a news release and a campaign Web site.

“Today, I am excited to announce that I will be running to succeed Congressman Moran,” Ebbin said in the release. “For over a decade in Richmond, I’ve been a strong voice for progressive values who’s gotten results.”

Euille and Ebbin will have plenty of competition for the Democratic nomination. Former Virginia lieutenant governor Don Beyer is in the race, as are Del. Mark C. Sickles (Fairfax), Del. Charniele Herring (Alexandria), Del. Patrick Hope (Arlington) and 2012 candidate Bruce Shuttleworth. Del. Alfonso H. Lopez (Arlington) is also expected to run.

On the Republican side, former congressional aide Micah Edmond has entered the race.