Why are Octopuses so tough and flexible?

They can squeeze though very small holes and bend around sharp jagged edges without being cut.
The common answer is, “because they’re boneless duh”. There’s more to it than that.
When an octopus forces itself through a space, its organs and brain must bend and stretch to fit through.

If your human organs got bent or stretched half as much, you would bleed inside and die.

So what exactly makes them so tough and stretchy?


The shortest answer is that the soft and rigid ones were easier to eat.

The thread title asks a “why” question, and (unlike most other scientific endeavors) “why” questions in biology are usually easy to answer. But the body of the post is really asking a “how” question, and those are much less trivial and more interesting to answer. How can octopus organs squish so much? What’s different about their structure and function that enables that?

Must they? Or are the organs and brain not particularly large and are just rearranged in the squishy container that makes up an octopus body.

I believe you are not a biologist, or expert on molluscs, and I’m relatively sure you didn’t take into consideration the actual size of octopus organs, or to what degree they can be rearranged, when you made this judgement.

That’s not to say octopus organs aren’t a lot tougher and stretchier than human organs, I just don’t think your assumptions about how much they are squeezed when the octopus changes shape are accurate.

What makes the human stomach so tough and stretchy? There are plenty of organs and biological systems that are tough and stretch, even in the human body. We’ve needed a stomach that is tough and stretchy, and have had no need for the brain being similarly malleable, so evolution has made it impossible to squeeze the latter through a small opening.

An octopus on the other hand has had completely different evolutionary pressures and therefore doesn’t have a huge firm human brain inside a hard skull. And possibly its much smaller central nervous system in its squishy body can change shape more easily, but if so that’s not all that surprising.

Mythbusters - Pop Rocks & Soda

Do their organs squish that much?

Consider a human. If we could be squishy the things we would not want to squish would be our organs. But they are (comparatively) small.

So seeing us squirm through a small hole might seem remarkable but it would only need to be as big as our brain or heart which we do not want to squish (not sure how much each could be squished without harm but I am guessing not a whole lot).

The brain often seems a limiting factor. As in many animals can squish through any spot they can get their head through intact. Rats, for instance, are famous for getting through holes smaller than you think they could. Octopi are even more squishy.

[quote=“Sage_Rat, post:6, topic:824274”]

Mythbusters - Pop Rocks & Soda


Strange that they tried to contact John Gilchrist since everyone knows he died several decades ago from a lethal combination of soda and Pop Rocks.

Perhaps not. What happens to your bladder when really full or a uterus when a woman is pregnant? I’m not saying this is analogous to octopodes but does show that thinking of organs as rigid objects maybe misguided.

Yes, but “can be compressed” is not the same as “can safely be compressed.” Consider the human heart–there’s a lot of space in there. Compressing it however seems like a poor idea.

Still hoping someone will weigh in on the octopus, though.