Narrator: This is Science Today. You may think the common tuna and the powerful great white shark don't have much in common, but it turns out that tunas and lamnid sharks - a group that includes the great white and mako - share a similar high performance swimming system. Robert Shadwick, a professor in the Marine Biology Division at the Scripps Institution of Oceanography, who co-led the research, says there's been very few studies on shark swimming.
Shadwick: Possibly due to the fact that they're harder to come by or they're not as easy to keep captive in certain species. So, I guess our work has done two things, which is point out the really interesting parallels with the development in tunas and also pretty much start off a series of papers on locomotion in sharks, which was a pretty empty field at the time we started.
Narrator: Powerful red muscles in the front of lamnid sharks and tunas transfer energy to the tail region - producing powerful locomotion in an area of the body that is physically separated. These characteristics distinguish lamnids and tunas from virtually all other fish, making them more like each other than they are even to their closest relatives. For Science Today, I'm Larissa Branin.