i like it!
but i think there are a few things you could fix:
when the players fish moves behind the attacking fish, the attacking fish should either:
good solution: draw it frame by frame turning around
bad but quick solution: put the action script on one of the fish:
if(_root.playerfish._x>_root.attackingfish){
_root.attackingfish.gotoandplay("turningrightframes");
}
and vice versa for turning left, did you understand that? hope so.
and an easy thing to do is when you get eaten, the music should stop and sad sorrowful tune should play as you fish gets munch into bloody little pieces!
hope i helped =)
ted