something's on my fish

A white oblong bump protruding from his side. Bigger than an ich spot. He is darting around as if irritated.

It showed up suddenly this morning- yesterday I did the usual 50% wc. I did add root tabs for a few plants, and fed him something he usually doesn't get- bits of crushed shrimp pellet (later in the day he got his usual 2 betta micropellets).

I took pictures to try and get a diagnosis on the forums. I think it's a parasite because it looks as if protruding from under the scales, but not sure- doesn't look like fish lice or anchorworm or any other pics I can find online.

I am not sure if this is something I can knock off by giving him a salt dip, or try to remove with tweezers, or if a medication will kill it... Trying to figure that out. Meanwhile, he's eating like normal and doesn't have clamped fins or anything like that.