That krill have sex at all may be news to many people. That they do it on the ocean floor is new scientific knowledge. I was invited to co-author a paper to help scientist So Kawaguchi explain his observation, captured on an underwater video system. I traced what I could see of the mating krill and combined the dancing lines with what I understood about shrimp sex and krill anatomy. I read scientific papers about what is known about how krill and related creatures reproduce. This new observation will help scientists manage fishing within the delicately balanced Antarctic ecosystem.