Of all the animals in the oceans, the hammerhead shark may be one of the strangest looking.  The exact purpose of the wide, flat head is a mystery, but several theories abound.  In this video, Jonathan travels to the shark-infested waters of the Galapagos in Ecuador and to a research station in Hawaii to learn about the unusual habits of these sinister-looking sharks.  He swims in schools of hundreds of hammerheads, and yet the sharks ignore him.  What are the sharks up doing? The companion study guide explores the reasons for the shark’s head shape and introduces cleaning stations and symbiotic relationships.