Greenland sharks are the world's longest living vertebrate, with a longevity that can be measured in centuries. But what do they do during that long life? In this episode, we speak with scientist and "Greenland Shark Detective" Dr Julius Nielsen, who has studied these mysterious creatures for many years. Julius was part of the first team to estimate their extraordinary lifespan, and explains exactly how they did it. He also walks us through some other fascinating aspects of their biology and ecology, including what they eat (answer: pretty much anything), how deep they can go (pretty deep!), their reproductive habits (becoming sexually mature at 150 and then having hundreds of babies, anyone?!), and some very unusual parasites… You can follow Julius on instagram and twitter: @juniel85 You can also follow Save Our Seas Foundation on instagram and tiktok (@saveourseasfoundation) and twitter (@SaveOurSeas).  Shownotes for this episode: https://saveourseas.com/worldofsharks/podcast