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.
I'm not so sure that Dr Kubodera's imagery proves this animal is or is not an agressive animal animal; his imagery certainly raised a few eyebrows though.
If you view those stills as if they were taken a fraction of a second apart then you would certainly get the impression that this was fast-moving and potentially aggressive animal, but those images were not taken a fration of a second apart (I cannot remember the exact figure, but 30 seconds springs to mind). If each still was taken at this frequency, and forgive me if I have this figure wrong (it is late and I really should check out Dr Kubodera's article on this), then the fluid motion you see in fast succession would render the animal anything but fast moving. Then again, just because something 'ate' (as in took a lure) doesn't make it aggressive, strictly speaking, just one of either opportunistic, predatory or hungry.
Having said this, Dr Kubodera, here immortalised with his very own TONMO emoticon (), is of the belief that this animal is not the sheepish giant that I believe it might be (and still believe it is), and I both trust him and respect his work immensely, and fully accept his opinion (and stand by mine). This is not disagreement at all - just different opinions on something, and this is not uncommon in the scientific community (and a good thing - diversity in ideas is good). What I do know is that it will not be long before we get to see this animal alive, in its natural environment, on film, without lures, and we'll be able to determine for ourselves just how this animal behaves. I will also add that to the very best of my knowledge it has not been filmed alive in such circumstances yet(!!!), but with the international interest in this animal it is inevitable that this imagery will be secured in the immediate future (I give it 2 years max before you watch it on television).
Thank you very much. I was just curious whether those photographs had any effect on your conclusions, given the dramatic arm postures which they show. The similarity of the posture over those thirty-second intervals would definitely indicate a slow approach, though, as you mentioned. It is rather difficult to tell from the photos I have seen whether or not the animal is approaching before it makes contact, or whether it has grabbed first, and drawn itself closer with its tentacles, which would fit in very well with the hunting strategy you describe. As you say, we will probably know soon, although I do wonder, given the cephalopods apparent sensitivity to pressure waves in the water, whether we might not be well advised to "hunt" with something that doesn't give off engine vibrations?