21/28 December 2019 | New Scientist | 53of this species interact in repeated, complex
ways, further eroding the generalisation that
all octopuses live purely solitary lives.”
In most octopuses, sex takes place when
males pass females a package of sperm called
a spermatophore or insert it directly into
them. Females in other octopus species are
able to mate with multiple males at once,
but by mating beak to beak, LPSO males can
monopolise access to a female. The behaviour
seems to help males guarantee that they
will father the subsequent clutch of eggs.
“She can’t crawl around and feed while
dragging the mating male in tow,” says
Huffard, as occurs in other species. “This
limits female feeding activity, but also limits
her mobility and keeps her close to her den
and the nearby male. It might limit her
exposure to other males.”
But what about the most celebrated aspect
of octopus biology, intelligence? Does group
living make LPSOs collectively smarter?
We already know that octopuses process
information in unusual ways, with their brainsdistributed through their bodies. Each arm
effectively has its own mini-brain, as does the
visual system. This allows them to multitask,
so an arm can explore or manipulate a food
item while the head gets on with some other
activity. This makes for eerily recognisable
behaviours. In the lab, the LPSO has been
filmed creeping up on a shrimp and tapping it
on its “shoulder” to startle it into its embrace.
But octopus intelligence isn’t necessarily the
same as ours. When they perform a complex
task, it might not be that they are weighing
up the problem and devising a strategy; they
may just be following a simple rule that often
results in a positive outcome. “We don’t know
whether their apparently complex behaviours
are even underpinned by complex intelligence
or whether they are using cognitive shortcuts
to govern such behaviours,” says Alex Schnell
at the University of Cambridge. In other words,
it could be all talk and no polka-dot trousers.
Octopuses of many kinds can, however,
learn, which Jennifer Mather at the University
of Lethbridge in Alberta, Canada, says indicates
the presence of an organising mind. As for why
they don’t show complex social behaviour,
Mather points out I am being anthropocentric
by even asking the question. “Every ‘way of life’
has its assets and liabilities,” she says. “Sociality
has its values, but it brings competition.”
Even these most social of octopuses
aren’t great at interacting with each other.
They don’t tend to be good at recognising
members of the opposite sex, for example.
This is hardly surprising: without much
generational overlap and a short lifespan,
there hasn’t been much opportunity for
evolution to work on social interaction.
All of which suggests we don’t need to fear
hyper-intelligent octopus communes plotting
the downfall of human civilisation. But there
is enough mystery left in these creatures
without hyping them as subaquatic aliens. The
recent discovery of complex social behaviour
in other species – as reported by Huffard for
the algae octopus, Abdopus aculeatus – shows
how much more there is to learn about the
intelligence and behaviour of this remarkable
group of animals. ❚With open arms: larger
Pacific striped octopuses
mate face to faceRowan Hooper is head of
features at New Scientist.
He is five social octopuses
in a trench coatThe standard English plural is
octopuses. That being said, the
word’s origins lie in the Greek
októpus (“eight foot”), so the
Greek-inspired plural form
octopodes is also sometimes
used. Octopi, while widespread,
adds a Latin ending to a Greek
word. It is therefore best kept
at eight arms’ length.One octopus,
many... what?“ There is no need to
fear hyper-intelligent
octopus communes
plotting our downfall”
RO
Y^ C
AL
DW
ELL
/UN
IVE
RS
ITY
OF
CA
LIF
OR
NIA
,^ BE
RK
EL
EY