Octopus emotions may run skin deep, researchers report January 28 in Current Biology. Changes in octopus skin color primarily function as camouflage, though some evidence points to other purposes.
Biologists from Australia and the United States spied on shallow-water octopuses (Octopus tetricus, also known as the gloomy octopus) feeding in Jervis Bay, Australia. Sifting through 52 hours of footage, they saw that the animals adopted a darker hue, stood tall and spread their arms and web when being aggressive or intimidating. Other members of the same species either responded in kind and fought or turned a pale color before swimming away.
Skin color changes appear to serve as a form of communication in these conflicts — the first evidence of such an octopus communication system at play in the wild, the researchers assert. The work also challenges the stereotype that octopuses are solitary and antisocial.
In Jervis Bay, Australia, a gloomy octopus (Octopus tetricus) displays aggressive behaviors: dark skin color, elevated mantle and spread web. Another octopus approaches and reacts by changing its skin to a pale color before swimming away to avoid conflict.
Credit: Scheel et al/Current Biology 2016