Researchers in Taiwan spent time studying the mating habits of the oval squid, or Sepioteuthis lessoniana, and published their results in the journal Frontiers in Ecology and Evolution. Their findings? The oval squid use color-containing cells called chromatophores to paint lines, spots, and stripes on their skin as a way to communicate with one another.
Researchers were able to spot these color changes in two ways: in the wild, by setting up a "home" made of bamboo branches and leaves in which a female oval squid could hatch her eggs over the course of three months; and in captivity, by rearing adult squids in a large indoor aquarium for two months. During this time, the researchers observed distinct color changes in both males and females: for instance, a female squid may produce a dark pattern on her skin to indicate that she's not feeling a male's romantic overtures. Or, when two males get into a fight over a good-looking lady, the winner may put on a strong visual display to show his success.