On O. vulgaris the underside of the arms is often purplish red including the sides of the suckers up to a dark rim around the white circular distal face.
Sublittoral, Setúbal, Portugal, November 2011. © J.P. Silva.
On O. vulgaris the underside of the arms is often purplish red including the sides of the suckers up to a dark rim around the white circular distal face.
Sublittoral, Setúbal, Portugal, November 2011. © J.P. Silva.