Cooler Than #SharkWeek: Bulking Up On Bull Shark Testosterone?

Discovery Channel has pissed off tons of its viewers—including me and Wil Wheaton—by launching shark week with the mockumentary “Megalodon: The Monster Shark That Lives”. With so much awesome shark science out there, it’s sad that they had to stoop so low for ratings. In response to the outrage, Brian Switek started “Cooler than #SharkWeek” on twitter, highlighting actual research on sharks. I’m continuing the movement by posting or reposting a blog entry about sharks every day this week. So instead of watching Shark Week, tune into Science Sushi all week for real shark science! Today we have an updated version of my 2012 Science Sushi post busting the myth that bull sharks are constantly raging on roids…

 

This startling image of a 1,000 pound bull shark circulated the internets, but what really caught my eye was a (mis)quote from the lead researcher. According to news outlets, he said that bull sharks “have the most testosterone of any animal on the planet, so that should tell you a little something.”

It wasn’t the first time I’d heard this whole bull sharks and testosterone bit. Indeed, all over the internet, you see claims that bull sharks are so aggressive because of their insane testosterone levels. But it was the character Bruce Kibbutz in Grand Theft Auto IV that really got people talking about bull shark testosterone. During the game, the roid-raging fitness freak explains how he juices on testosterone taken from Chilean bull sharks. Suddenly, extreme body builders and skeptics wanted to know if you could really bulk up on bull shark blood.

The rumor, as I’d heard it in college, is that the fierce attitudes of these large and aggressive sharks is due to unfathomably high circulating levels of testosterone. Specifically, these menacing monsters supposedly have higher serum testosterone levels than any species on the planet, land or sea, and that even a female bull shark has higher levels than a testosterone-raged male elephant in musth. I know I’m as much to blame as anyone, as I’ve repeated that line myself. But when I was asked about it, I realized that I didn’t know if it’s true. How do the circulating testosterone levels compare between bull sharks and other species? Could you procure enough testosterone by catching and eating bull sharks to beef up your body? Continue reading “Cooler Than #SharkWeek: Bulking Up On Bull Shark Testosterone?”