This robot fish is "as silent as a spy" — and could help researchers learn even more about the ocean 01:05. The mysteries of the ocean abound. And now, a group of student researchers is trying ...

The researchers are studying how fish use their muscles to swim efficiently and execute underwater maneuvers, such as darting around in perfectly synchronized schools.

Only a tiny fraction of those images ever get analyzed, because on average, it takes a human expert two hours to identify and count fish in a video that is one hour long," she said.