Great stuff I am completely clueless about and ignorant of, Andy! Thank you for the edifying post. I appreciate it and will pay it some mind and will plan to do some more reading. Maybe even the calling, you are suggesting, albeit I don't foresee it being "easy" unless a genius doctor or wildlife officer suddenly answers my ring, haha...
Freezer burn is possible but not likely as the frozen fish is packed properly in a plastic sack inside a carton box. But indeed, it might have stayed frozen for a year or longer by the time it was fed.
Red tide PSP is too possible because it is in the area indeed.
A sloppy (can't be proven or refuted kind) argument against both suggestions of yours is that
-- I feed more than just the mullet (there are several other fish species I feed that come from various geographies caught by commercial baitfish fishermen plus yet some others I catch myself) and
-- that no other of our resident consumers of the mullet and other large frozen bait fish I feed have been affected in a way that I could connect with the orange jello catfish illnesses and passing over the roughy 1 year period... and we have great many other fish that are fed roughy the same cuisine.
Yet, we have been suffering a long and drawn out series, 3-4 years long, of varying severity, of unknown lethal illnesses in a small portion of our small grow out fish that get fed an entirely different cuisine from different sources. The symptoms of those illnesses have been of the two kind - one where a fish becomes discombobulated and slowly perishes over a week or a month or even several months and the other that with Duanes suggestion was identified as possibly a columnaris strain of sorts, which came into our system later than the first, roughly 1 year ago, namely with the introduction of some fish that originated from the local wild.
If the jellos were affected, it'd be by the first bug, in my feeble mind anyway.
Their passing seemed consistent with something missing in their diet too not with a slow poisoning, albeit I believe I have never dealt (knowingly) with the latter. Perhaps these express themselves similarly.
Hence, I maintain [1] a bug or [2] the imbalanced diet of almost exclusively frozen marine fish... for the lack of more personal knowledge, which I appreciate you trying to expand my horizons, my friend
Kudos for you!
