Fishing: There is more to it than you think
Fishing is a good way to increase your professor's level without spending any points of activity, such as a bonus from stocks of ingredients to have food. Sometimes on Sundays there will be events where rare fish become available for catching, which you can sell for cold, hard cash. But it is important to hunt smartly, which means you do not necessarily have to unwind in the first fish that bites!
When a fish catches, there will be an icon indicating how rare the fish will be. When using expensive fish to catch rare fish (for example, during a special day of the event, for example), you will want to wait for the fish icon to appear purple, gold or arc to make sure you make the most of him.
However, there is a risk of losing your bait after the third bundle, sometimes fourth if you are lucky. So try and get out while you're ahead.
Here is how the scale of the rarity:
Blue -> Red -> Gold / Rainbow / Purple (only for special fish events)
in the mini-match, the better the fish! Either way the game is called.