Blue Rockfish with slime in there stomachs?

Went fishing up north Ocean Cove caught some nice blue rockfish they looked healthy took them home started to fillet them out this clear slime came out of the first one. OK so I did another one same thing so the next one I squeezed it stomach before filleting and this clear slime came out of the stomach of all the blues. I don't recall ever seeing this before and wondered if anyone else has seen this? There was nothing in there stomachs except this clear slime about a 1/3 a cup in all the blues.

Could it be jelly fish half digested?

That is a good thought. While fishing I did not sea those swarms of jelly fish we see but ya that could be it. Do blues eat jelly fish would be the next question?
I just don't remember seeing this much fluid coming out of the stomachs when filleting these blues before.

OK well I just googled it and yes they do eat jellyfish although I did not see any whole jellyfish in the fluid but I am going with that is what it is.
By the way they we going to be fritters anyway it was not going to stop the food chain...LOL
Thanks for the answer...

Yes blues like the sail by wind jellyfish.   You can put one on a hook and catch a blue.

Ya know I have been rock fishing for 52 years you just never stop learning about the ocean and fishing in it.
Jelllyfish for bait wow who da thought that. Never seen a jellyfish lure that could be hot!