If anybody is interested in trying to create a mod that allows for picking up fish in the new 1.21.1 update, that would be really neat (especially with the new fish!). I'm usually the one known for creating aquariums in my minecraft worlds, but haven't been able to successfully make one in VS.
Ideally I would be able to pick up a fish and place it down alive, as well as having the action of picking up the fish remove despawning (or using some sort of method to remove despawning).
A few net mods allow picking up other animals such as lizards and bugs, but there aren't any for fish as far as I know.
Anyway, this is just if anybody is curious or interested, just putting it out there. Happy surviving!