As far as bloat goes, I have heard of other species getting bloat. I think they have to swallow their prey whole like a grouper or betta and definitely other scorps. Fish like puffers and triggers and such chomp up their food, so I don't think bloat will apply here. Eels possibly or maybe some other digestive issue, as they can get blockages due to an poor diet. Thiaminese is a compounding issue, having a thiaminese dominant diet over months for some species, and years for some, will eventually take it's toll.