The largest ray in the world (up to 8m wide!), the giant manta is a graceful and gentle creature. They can make migrations across the oceans, finding their way by following topographical maps ...

"By mimicking the manta ray's fluid silhouette, we've solved buoyancy and stability issues that plague humanoid underwater robots," said Fan Dixia, 35, the project's principal investigator.

A US military submarine that looks like a giant metal manta ray and is currently under development passed its first major test at sea. The unmanned prototype aptly named "Manta Ray" completed ...