Cephaloblogging Friday: Arms, mating, evolution

Here's a fun and out of context fact from Wikipedia:

When under attack, some octopuses can detach and autonomise their limbs, in a similar manner to skinks and other lizards. The crawling arm serves as a distraction to would-be predators; this ability is also used in mating.

Wikipedia didn't explain further how octopuses* use their detached limbs in reproduction. Any cephalogeeks** want to elaborate? Is this just another example of guys' showing off in pursuit of sex? Or something kinkier?

Meanwhile, mostly unrelated except for the arms part, the NY Times reported that:

"octopus...arms are highly flexible in a way that the arms of vertebrates, including humans, are not.

But when an octopus fetches a piece of food, researchers have discovered, it can transcend its invertebrate ways. Rather than curling an arm completely to bring the food to the mouth, the octopus stiffens portions of it and bends it at three points...

As the food was drawn to the mouth, the arm began to bend. One joint was near the food, one was near the body and the third was midway between the two. Most of the bending occurred at this mid-joint, with the far joint rotating at the last minute to put the food into the mouth...

The work suggests that the octopus has evolved an arm-movement solution that is similar to that of vertebrates, although it is based on a completely different mechanism."

Which makes sense: octopus eyes evolved independently from mammals, but function in a manner similar to mammals (iris to control light, etc.), too.

*Wikipedia cites the OED in saying that octopuses is the preferred plural; octopi is second in frequency based on the mistaken belief that octopus derives from Latin. It actually derives from the Greek oktopous, which would be pluralized as oktopodes if we were trying to be consistent. Fortunately, we optimists value consistency in logic but not in language. OED does list octopodes, but says it is rare. Feel free to use it to impress your friends, though its use isn't recommended as a reproduction[geek]strategy.

**Note that geek in this context is an affectionate term, since anyone who finds his fun in octopus facts must be one. I haven't looked, but I suspect there's lots of overlap in the "fun" and "science" categories in this blog, which is a science-geek tell. No offense intended to fellow geeks, especially of the cephalo-variety.