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Octopus chierchiae mating, The male is mounted on the female. The male's 1st. 2cd and 4th pair of arms can be identified by the presence of papillae on the arm tips. The 3rd pair of arms do not have papillae. The hectocotylus (3rd right arm) is visible at 11 o'clock. If you look about half way down the length of the hectocotylus you can see a section that appears to be contracted. This may be caused by a peristaltic wave passing down the arm. I've never seen this before and would be interested if you have seen something similar.