About this print: Octopuses are often considered to be among the smartest invertebrates (animals without a backbone). This is a macro photo of a male Ruby octopus (Octopus rubescens) that I had the privilege to check out while at a research station one summer. We know that this is a male octopus because of the oversized suckers visible on the right-hand side of the image. For this species, these over-sized suckers are at the base of each arm on males. Besides having really cool sucker-lined arms, octopuses (and other cephalopods) have the ability to change their skin color using special cells called chromatophores. These light-reflecting or pigmented cells can be used to help octopuses blend into their surroundings, ward off predators, and communicate with other octopuses. In this image, chromatophores are abundant and visible all over the octopus’s body and even on the octopus’s arms.