Need some help with fish animation

Working on a bit of animation to simulate fish swimming.

What I want to do is make it a bit more realistic, but don’t really know what to do next. I would like to make it so the fish tilt up or down a bit when they are swimming in that direction. This would probably involve adding some rotation to the movie dependent on if its going up or down.

Also, I would like to make it so the fish tend to swim away/scatter from the mouse pointer, yet I have no idea how to do this.

Still new to flash, any and all help is appreciated.

File attached bellow.