I think that MOST of the time you should catch regular fish (50%), OFTEN you should catch salmon (30%), SELDOM you should catch clownfish (15%), and RARELY you should catch pufferfish (5%). I feel that these proportions seem fair and reasonable per fish.

Fish: the common fish, general population,should be more often caught.
Salmon: satisfies a little more food than fish, should be less often to catch
Clownfish: not a good source of food, but are great decorations, IF you ever catch one nowadays.
Pufferfish: these tend to stack up when you don't need them for your one type of potion. It should be rarest BECAUSE it can be turned into a potion.

With a group of 4 friends, we've caught 3 clownfish, 15-ish regular fish, 35-ish catfish, and 40+ pufferfish in a period of about 2 hours of fishing...

...also we should revert to the original pufferfish texture, the new one is UGLY.