Who is observing whom?

During a dive to the deep-sea hydrothermal vents at Guyamas Basin (Gulf of California, Mexico), an octopus eyes the submersible Alvin. The dive was conducted as part of an R/V Atlantis research cruise funded by the National Science Foundation to investigate the ecology and geochemistry of microorganisms that ‘eat’ natural gas. (Photo by Stefan Sievert, Woods Hole Oceanographic Institution)