Jed Gould, AKA "Jed The Fish" -- a longtime DJ at renowned L.A. rock radio station KROQ -- has died, TMZ has learned.

Jed's death was announced on his Instagram account this morning, in a post noting he died at 6 AM today at his home. Megan Holiday, a current DJ at KROQ-FM, tells TMZ ... Jed died from lung cancer. He had recently been diagnosed with the disease, and unfortunately, he experienced a very rapid decline.

Jed joined KROQ way back in 1978 ... the station has long been known as a big-time outlet for alternative rock, new wave, and punk rock. Jed last spun records on the air there in 2012, when he left his afternoon slot, and later returned as host of a 1980s-music-themed satellite show ... and he's worked a couple other station gigs around California, before and after his KROQ tenure.

Jed's been named the Billboard Modern Rock Personality of the Year twice, as well as the Radio & Records Local Modern Rock Personality of the Year. Various other co-workers and broadcasters are paying tribute on social media this morning to the prolific rocker.

Jed Gould was 69.

RIP