Change the running AnimationState of an Animation

Hello everyone !

I'm new using animations in unity. I created in blender 3 animations for a fish mesh and I now have 3 animations clips. For now, I have attached to my mesh's animation; one main clip as "animation" and in my "animations" list my 3 clips like this:

My main animation "mouvement" is running, but i would like to be able to change to another one.

I tried this in code:

     Animation anim = fish.GetComponent<Animation>();

     anim["mouvement"].enabled = false;
     anim["left"].enabled = true;

It stops the "mouvement" animation but doesn't run the "left" animation. Is there a way to do it ?

PS: I also thried with the an Animator, but when I drag a clip into the animator windows, it creates a state, but the clip inside it is set to None I can't put one of my clip (even if I can change it to other clips already present in Unity).

PS2: all my clips are working, I tested it bu changing the main clip in the mesh animation