It sucks to swim like a jellyfish, study of animal's movement suggests

Discovery by Stanford University researchers could challenge assumption that ability to 'push' water is a widely desired evolutionary trait

For the longest time, science has assumed that in order to run, swim, or fly, animals and humans must exert pressure on the ground, water or air around them to project themselves forward.

But a study published on Tuesday suggests that rather pushing water rearward, jellyfish and lampreys - a species of snake-like, jawless fish also known as lamprey eels - "pull" themselves forward by creating a region of low pressure in the water ahead of them.