Most consider the saltwater catfish non-edible, but I know many born and raised Floridians that do eat them and claim they taste good. They do skin them first which requires some work. So, your answer is: they are edible but generally not eaten.
Tarpon is considered totally non-edible, but if it was edible, you would need a tarpon tag in order to have one in your possession. I do not know anyone personally who has tried one, but I do hear that Bahamians eat tarpon, but they grind the flesh up along with the bones, season it with whatever they have on hand, and fry it like a fish cake. So, the answer for tarpon is; they are edible but not eaten because it does not taste very good. They are also looking to take away the tarpon permit/tag from recreational anglers because of this. Their value is in the pleasure they give an angler when they are hooked. Now, Tampa Bay does have a huge list of very great tasting and edible fish, the list is very long. These two are just not on the list of fish people normally eat.
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