Question

Would mouth to mouth resuscitation between two fish work?

Answer 1

I don't think it will work.

Fish breathe with gill not lungs. Unlike lungs, gill works one way. You breathe out air out of you mouth but fish dump the water from their gill so they shouldn't be able to push water out of their mouth.

Even if the could fish push the water through their mouth, the gas exchange didn't happen because the water didn't move through the gill. The fish that giving water cannot breathe while giving resuscitation.

Answer 2

Is this a joke?
XD XD