WASHINGTON -- Rep. Jose Serrano, a 16-term Democrat from the South Bronx, says he has Parkinson's disease and will retire at the end of his term.

The 75-year-old Serrano is a fixture in Bronx politics and is among Congress' foremost defenders of Puerto Rico, the U.S. territory where he was born.

He's chairman of a House Appropriations subcommittee with jurisdiction over the departments of Justice and Commerce, and he's pledging to use that post to -- in his words -- "fight for climate change research, a fairer justice system, and an accurate 2020 census count."

Serrano's announcement came shortly after a New York City councilman, Ritchie Torres, announced he'd run for the congressional seat in the strongly Democratic district.

In explaining his decision, Serrano says Parkinson's "will eventually take a toll."