Odd red grouper filets

I've shot 3 red grouper in the past couple weeks, and 2 of the 3 have had this black thing in one filet. Both in the same location, in the top part of the filet, very close to the head. I didn't think much of the first one, but the same thing on two different fish in the same exact area seems a bit odd. Any ideas?

Worm it is I guess. I've seen plenty of worms in fish before, but none that look like these. It looks like a small black pellet. Are they a different type than the worms I'm used to seeing?