I feel like fish should be able to be sold in the bazaar. This is because of the general helpfulness it would provide, and an inconsistency in what is sold at the bazaar. Let's review the purposes fish serve:
1. Housing items: Fish can be put into aquariums and admired in your castle. 2. Crafting Materials: Fish are used in crafting teleport tapestries, high-level decks and others.
Looking at the bazaar, there is a section for furniture, and there are bazaar sections for the other materials used in crafting (reagents, seeds, treasure cards). If we can trade all of these, why not fish?
Furthermore, it would help out those of us who do not have the time, energy(literally, our energy is already spread thin between pets AND gardening) or will to fish.
I'm not sure about making them sellable at the bazaar as that would bring the demand for fishing down a lot however making them tradable between characters i believe is a brilliant idea!