Do cephs sleep?


Feb 9, 2008
East Haven,CT
I assume so because of their advanced brain, but I can't find out much on this issue. It appears my hummelincki goes to the same area every night after 12 and doesn't move at all or react to my finger (when blue LEDs are on until 12:30). Does anyone know about the sleeping habits of different cephs?
'tis hard to say. I'm not sure anyone has done sleep studies on octopus. Certainly they seem to have a definite resting phase. Even in fish there is huge argument on whether or not they sleep, some say yes some say no. There is a lack of features in brain wave activity (such as REM sleep) that you would expect to see in a sleeping human.....but should we expect to see the same patterns in a creature that is so very different to us?
Although ceph brains are very complex and can do impressive things, they are organized so differently from vertebrate brains I would be surprised if they had something exactly like sleep, and very curious about the similarities and differences. I certainly don't think that the argument about "advanced brains" needing sleep is necessarily valid: our last common ancestor was some precambrian thingie somewhere between a leech and a limpet, probably something worm-like... I doubt it needed to sleep, so sleep would have evolved separately... which would imply that it's somehow fundamental in advanced intelligence, whereas I think it's more likely that it's a quirk of the vertebrate nervous system... As Jean says, I'm not sure it's clear that fish (or amphibians, or even all reptiles) sleep-- this only lists mammals, and this has some comments on birds and mammals, but not reptiles, amphibians, and fish showing REM sleep signs (although they have a rather naive interpretation of birds descending from reptiles: my impression is that modern classifications have birds descending from dinosaurs having split off from the cold-blooded reptiles quite a bit earlier.)

Anyway, as in the discussion of cephalopod consciousness it's very interesting to consider the similarities and differences in diverse animals with advanced brains, so if cephs are found to sleep in ways that correspond to mammal sleep, it would be very interesting to compare-and-contrast the elements that are similar and different: is sleep important for converting short-term memory to long-term memory? Is this necessary for any memory system based on nerves?
Without being able to define sleep, observation of inactive times will have to do. Both my Mercs and my Hummelincki sleep on a regular basis at regular times taking a pose and location different from their active time habits. The Mercs do not always choose the same place but do leave the open water for a sheltered environment and take the same position. The Hummelincki takes both the same place and position in his/her inactive state.
We now have reasonably strong evidence (behavioural, attentional and electrical) that Octopus do a kind of sleep. See the paper

Brown ER, et al 2006 Behav Brain Res.;172(2):355-9.

Octopus vulgaris maintained under a 12/12h light/dark cycle exhibit a pronounced nocturnal activity pattern. Animals deprived of rest during the light period show a marked 'rebound' in activity in the following 24h. 'Active' octopuses attack faster than 'quiet' animals and brain activity recorded electrically intensifies during 'quiet' behaviour. Thus, in Octopus as in vertebrates, brain areas involved in memory or 'higher' processes exhibit 'off-line' activity during rest periods.

If you would like a copy of this paper I can forward it

Oh my -- had I done a keyword search before initiating the new To sleep, perchance to dream thread, I would've continued the discussion on this one instead! At any rate, this old thread is particularly helpful and relevant to my query, and if anyone is following it, please continue the discussion on the new thread.... this is a great subject!
does anybody know how well, if at all, octopuses adjust to shift work? can they easily bounce around their inactive period and match the owner no matter what the routine, or to they need a period of adjustment? im not after any real scientific studies, just curious about wether anyone here works shifts, and how their animal coped.
Both my mercatoris' (nocturnal pygmy) and my hummelinckis (diurnal) showed signs of needing a routine. Their active period could be adjusted somewhat (more with the hummelincki) by altering the photo period but on more than one occassion I have seen my hummelinckis "go to bed" seconds before the lights went off. Additonally, when our red night light would turn white because of a power failure (the light has multiple color settings but the initial on is white light) Octane (hummelincki) would pace and act very nerveous after lights out until we discovered and corrected the problem (after several episodes we just removed the night light). My thinking is that you can establish a routine using lighting but continually trying to change it would be problematic and likely to stress the animal.
just thought i would add what i have observed

our Giant cuttle Sepia apama often has 'off' days
during these he will sit at the bottom and close his eyes (eye lid moves up from below as the eye lowers slightly)
during this time i have noted him Flinch (tentacles and skin around the head) from time to time, colour and texture seem to stay reasonably constant during this time

first thing that sprung to mind was "aww just like a sleeping dog dreaming of an adventure"

Sorry for dragging old threads up from the depths
This is interesting.

As I mentioned in another thread - I saw two Octopuses today at an Aquarium, both of whom seemed to be in a state of deep rest when I first saw them.

Both were a very pale 'yellow' at first, not entirely in synchronous camouflage with their surroundings. One 'woke up' (For wont of a better phrase!) but the other remained perfectly still, apart from breathing. Later, as we passed the tank on our way to the exit - Both had gone into hiding.

From what I observed, I could reach no absolute conclusion as to whether or not they 'sleep' - In the human sense. But certainly, I saw an octopus in a state of deep rest, with little apparent self-concern (Otherwise the camouflage would have been more effective I think)

When humans sleep, they are unaware of their surroundings, and are therefore disinhibited. For creatures (Octopuses) that are normally quite defensive, this resting behavior, and the lack of inhibition it included was certainly indicative of a form of sleep recognisible to humans.
If you don't qualify sleep as a brain activity/memory transfer requirement (because we don't know what happens with an octopus in this regard) but as an at rest state where the animal is unaware of its surroundings, then I have observed sleep in all the octos I have kept. Touching one in this state will almost always get you an inking incident once it wakes up.
Samuel Pepys (Famous 17th Century Diarist) once ended an entry with the line:

"And so to bed, perchance to dream."

Humans certainly show differing brain-wavelength images during our various depths of sleep and dreaming.

An Octopus doesn't? [[EDIT. Sorry - That's what I originally wrote - But I see that you said: we don't know what happens with an octopus in this regard. Sorry, again :P]]

[[RE-EDIT. So rather than saying An Octopus doesn't? - I should have said We don't know if Octopuses do, or do not?]]

There is, from your observations with your Octopuses - And mine with humans, a striking similarity however (Which you've clearly spotted! :P)

Never wake ANYTHING up when it least expects it - Because all bets and inkings are off, if you do!

It all rather leads to the question - Is sleep, and dreaming (in most animals) something which can only be determined or mapped electromagnetically - Or are the EM waves species/variant unique - And not conducive to a conclusion on sleep or 'dreaming'?

In any case, have you (Or anyone else) got a copy of Cephalopod EM graphs during various states of agitation?

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