A shrimp "swims" by quickly bending its stomach in toward its carapac. They shoot through the water backward when they do this. They have no fins. You can find more information here: http://research.myfwc.com/support/view_f...

Because the shrimp does not have fins like a fish, they swim by pushing off of their abdomens. This shoots them through the air which allows the shrimp to move very fast through the water. You can find more information here: http://www.youtube.com/watch?v=pabV_3abs...