I never did find out - but I'll bet you dollars to donuts (actually not such a good deal these days - paid a buck for a cinamon roll this morning - but you get my drift) that it is some artifact of the molding process.A big fish like this is bound to get some substantial dents in it after sitting on ice for a few days. I imagine it may be standard practice toput something into the cavity to push the dents back out. Or it even could have been a fungus or something going on inside the dead fish, perhaps the result of some preservative chemical or something going on biologically that I've never seen before. I do NOT suspect Darin of any wrongdoing. It was weird-looking, though. I was going to weigh the gonads of the fish and one of them was full of the stuff, inside the ovary - or it even looked a bit like the ovary had turned into the stuff, because it was'nt any larger as a result. It was hard to tell where the ovary began and ended, where it was all grey stuff. So I did not get total ovary weight. The grey stuff was no heavier than regular biological material - not like bondo - and it was as soft as ovarian material, or softer - not like clay or anything like that. Incidentally, if I was going to try to doctor up the weight of a fish by adding something to the cavity, I would have added substantially more material than what I found here, unless I was trying to barely knock the weight up over some target weight. Darins fish was WAY larger than the previous record, and theweightof weird stuff on the inside of the fish would not have made a substantial difference. Why put an obviousworld record in jeopardy by stuffingenough weight in it to make it a just barely largerrecord? Doesn't make sense. I don't think that was the reason for your question, but I figured someone would think of that question eventually, so I wanted to put my two cents in on it right away.