Welcome to TONMO, the premier cephalopod interest community, and birthplace of #WorldOctopusDay and #CephalopodAwarenessDays. Founded in 2000, we are a large community of experts, hobbyists and enthusiasts, some of whom come together when we host our biennial conference. To join in on the fun, sign up. You can also become a Supporter for just $50/year to remove all ads and enjoy other perks. Follow us on Twitter for more cephy goodness.
Not with a microscope unless you bop it on the head and dissect it!
As it gets older the male will develop a modified arm (the hectocotylus) often the third right, which may take the form of a scoop or club shaped end (some species develop grossly enlarged suckers) This in a mature or even maturing animal is visibe to the naked eye!