Fish that require a bait to be caught can only be caught with the listed bait, Higher tiered baits don't capture any other category other than what they are listed as.
In order to purchase baits you must level up your skills to the required level and have enough Entropy to purchase.
Usage is not final,subject to change.
Baits do have limited usage, and can be applied to only one fishing rod at a time, Each custom fish you capture will consume a peice of bait.
You can purchase multiple baits and apply them individually to other fishing rods if you desire.