21 July 2017
Vol 357, Issue 6348

About The Cover

Cover image expansion

COVER Atlantic bluefin tuna in the Mediterranean Sea. The hydraulic control of fins discovered in tunas indicates a previously unknown role of the lymphatic system in vertebrates. This fin control mechanism may inspire the design of "smart" control surfaces with changeable shape and stiffness that could enhance the maneuvering performance of unmanned airborne and underwater vehicles. See pages 251 and 310.
PHOTO: Brian Skerry/National Geographic Creative