Spawn for fishes in rivers?

Good morning/evening Mojang!

This is my second idea! I know it is too late for this, but can You add spawn for fishes in rivers?

Here is the mechanics:

When player picks the water from river to bucket, it will be 1/1000 chance to have the spawn in bucket. Then, when player pour the water in the hole, in two Minecraft days there will swim small fishes!

I'm so sorry, because I'm Polish and I don't well speak english.

Have a nice day!

SirThunderek (GrzmociQ)