Crustaceans are near the top of the list of the most thiaminase-loaded feeds.
I imagine that crustacean specialist fish, like puffers, spiny eels, etc., must have their biological defenses against these issues but generalist or piscivorous predators like B. juruense would not.
Insectivorous and picsivorous arowanas I'd imagine would not either. Cats cannot be lumped together like arowanas, with their handful of species of similar biology, except maybe the African aro, because there are 3500 known species of catfish and about as many unknown yet. They have vastly different requirements. Although perhaps I agree that the majority of predatory or omnivorous monster catfish we keep might be lumped together.
Anyhow, sorry if this was all obvious... I think that if your shrimp pellet is high quality, it may provide for the right amount of vitamin B1 to balance out the largely shrimp diet. If not or if unclear, I'd either transfer the juruense onto mostly pellet feed or feed it mostly fish, whole the best, of several kinds to diversify or soak the feed in Vita-Chem or in B1 vitamin solution in particular... at least every now and then, I guess.
Below the adipose in black on white
Good eye.
