[MUSIC PLAYING]
SPEAKER 1: They can crawl.
They can squeeze and hide.
They can even use
jet propulsion.
And just when you think
that octopuses couldn't
get any more versatile, they up
and walk away. [MUSIC PLAYING]
And while it's utterly absurd to
look at, once we stop laughing,
maybe we should ask why would
one of the most agile creatures
in the ocean choose to scamper.
Backwards.
That momentous question
captured the attention
of Dr. Chrissy Huffard, a Senior
Researcher at the Monterey Bay
Research Institute, whose
graduate studies at UC Berkeley
focused on cephalopod behavior.
DR. CHRISSY HUFFARD:
Generally, I
try to understand
how octopuses survive
in their everyday lives,
avoid being eaten,
find mates, and find prey.
SPEAKER 1: Documenting
the survival strategies
of octopuses isn't easy.
You've got to be willing
to spend a lot of time
on remote tropical beaches.
DR. CHRISSY HUFFARD:
My job is a lot of fun.
I wake up at dawn every
morning, get in the water,
and get out for a brief
snack at low tide,
and then get back
in until sunset.
SPEAKER 1: It's hard work,
but somebody's got to do it.
DR. CHRISSY HUFFARD: Unlike
other octopus studies
that had been done,
I was actually
able to follow individuals
all day long on snorkel.
SPEAKER 1: Particularly,
the cryptic algae octopus.
DR. CHRISSY HUFFARD:
The algae octopus
tends to come out during
times of day and tides,
and in certain
habitats that mean
they tend to clump in the wild.
And there are lots
of individuals
that use the same area
and prefer that same area.
So they're bumping into
each other, mating,
fighting, competing
for similar resources.
And I could watch this
happen in real time
and pretending I wasn't there.
SPEAKER 1: Although on
occasions, her subjects
realized they were
being observed.
DR. CHRISSY HUFFARD: I am
assuming that they considered
me a predator in those cases.
Octopus's main defense is not
to be seen in the first place.
That's their best chance
of not being eaten.
SPEAKER 1: And if all else
fails, they can just jet away.
SPEAKER 1: And in
that shape, camouflage
isn't even a possibility.
SPEAKER 1: It was in one
of these defensive moments
that Dr. Huffard witnessed
an entirely novel
attempted escape.
DR. CHRISSY HUFFARD:
I was working
with a film crew for a
documentary series called
the Shape of Life.
It was easy to get
them to act defensively
when you're chasing
them with a camera,
and we got footage of the
coconut octopus walking
on two arms.
Oh, it was hysterical to see.
We laughed and our masks filled
up a little bit with water.
Then later I saw the behavior
in the algae octopus.
We again laughed at how
hysterical it looked,
but also we understood the
biomechanic significance of it.
Octopuses have very
strong arms even
though they don't have bones.
They have three bands of muscles
that oppose against each other.
And the volume of those
muscles and their arms
stays constant as
it changes shape.
That's called a
hydrostatic skeleton.
That allows them to use the
internal pressure of their arms
for support.
SPEAKER 1: But just because
an octopus is physiologically
capable of walking
backwards, doesn't make it
the best form of escape.
Or does it?
DR. CHRISSY HUFFARD:
When octopuses jet
to escape a predator,
there's so much
internal pressure
that's built up inside
of their mantle cavity, or
inside of their body sac,
that it actually stops
their hearts briefly.
SPEAKER 1: Going
into cardiac arrest
while swimming away in a
panic, probably isn't ideal.
DR. CHRISSY HUFFARD:
Walking backward
allows them to use two of
their arms for locomotion
and six of their
arms for camouflage
or to otherwise make their
shape seem unrecognizable.
SPEAKER 1: And while only
a few species thus far
have been documented fleeing
on foot or rather arms,
Dr. Huffard believes that
this escape plan isn't
a difficult trick to pull off.
DR. CHRISSY HUFFARD:
Just the way
we don't have to stop
and think move left leg,
move right leg, it's a type
of motion called feed forward
movement, where it's almost
automatic once it gets going.
And I think it was part of their
normal locomotion repertoire
of how they can move around.
SPEAKER 1: Yet
another method for
these skittish invertebrates
to show off having no backbone.
For Science Friday,
I'm Luke Groskin.
