Are octopuses able to hear?

[lene]

Hello,

I study biology in germany and have a question about the sensation of octopuses. Are they able to hear? It may be a stupid question but I can´t find out whether it has been answered or not...

 

[Graeme]

... actually that's a good question! I don't know the answer, but since they seem to focus on a more visual world and chemical world, I would hazzard a guess and say a possible no, if not having a good sense of hearing! I've never seen any such organs in a ceph before. Have you tried looking on either Google or Google Scholar? I find scholar one of the best resources for finding scientific papers.

Graeme

 

[Graeme]

Octopus- Enchanted Learning Software
In anatomy


http://www.scienceyear.com/parents/index.html?page=/parents/party_time/undersea/activities.html

Hope this helps! Although they seem to be all just kids' sites, with no mention or reference to their sources.... unless I'm just not looking hard enough!

Graeme

 

[lene]

I actually found out that the species Octopus, Loligo, Sepia and Vampyroteuthis are indead able to recept vibrations under water and sense pure tone of 600 Hz. This sound-technique is common on sqiud fishing boats in Japan.

This is based on an publication of Hanlon and Budelmann in 1987. Professor Hanlon is still researching at the Woods Hole Marine Biological Laboratory in Massachusetts. But there is still no answer in the www to my question if they do communicate by sounds... Maybe I will find out when I undertake my studies. Thanks for the reply!

 

[Taollan]

In my work with GPOs in the San Juans, have been able to get them to respond to the clicking together of rocks outside of their dens (ie, I would come to the dens once every few days and give them a crab, and clicking the rocks together before I gave them food. Before long they would come out as soon as I clicked the rocks). I haven't done any quantitative work with it, but seems suggestive.

 

[Graeme]

That's interesting! I suppose it would be very likely that they can detect vibrations through the water, since what is sound but vibrations? Could it be the vibrations caused in the water by the clicking rocks, or water disturbance caused bu the movements under water? I know they can pick up chemicals in the water easily, could it be chemicals from you hands (ie. smell?) it's most likely "hearing" the clicks, I really don't know enough about a cephalopod's sensory system.

Graeme

 

[Euprymna]

It all depends on what you call by hearing. Sound is difficult to define in an aquatic environment. There has been quite debate on whether they can hear or not (Moynhian said yes they are deaf, Hanlon said no they are not). All I can say is that when I tap on tanks holding octopus, they change colour like when I do a sudden fast move over them. Is it actually the sound or the vibrations of moving water produced by the tap disturbing them?
I think this has been previously discussed in a previous thread...

Now can cephalopods communicate by sound...I cannot think of any organ capable of producing sound and haven't heard anything about that...but you always learn new exciting stuff so...

eups

 

[bigGdelta]

if they can detect the vibrations then it's close enough to hearing for me.

 

[Jean]

One of the presentations at CIAC dealt with this topic. When I catch my breath I'll look out my notes on it!

J

 

[ArchyNorth]

Now I may be showing my ignorance here but,

Sound is caused by waves in the air that vibrate the eardrum. These vibrations are then registered by the brain as sound. I know that this is a simplistic description but am I generaly correct?

If I am, then can't water then be viewed as just another medium that the waves travel through? If the animal can sense these vibrations and then have its brain interpret those signals, couldn't that be termed as hearing?

The animals may not have an "eardrum" as we see it, but couldn't they have another way in sensing these vibrations? Being how "thick" water is and how well vibrations (sound) travel in it, maybe the animals entire body could be seen as an "eardrum".

Anyway, just some thoughts.

Cheers.

 

[Toren]

Like at band practice when I can feel the bass through the floor!

 

[Graeme]

Yeah! when you go to a gig, the music's so loud the whole place vibrates with sound! You don't just hear it, you feel it. I think that in water, vibrations travel better, which means that sound travels better in water than in air (it doesn't attenuate or something) and so it owuld be possible for an octopus to detect the sound vibrations, whether it actually physically hears them or not... I guess.

Graeme

 

[Tintenfisch]

Someone actually presented on this very topic at CIAC... but I missed it. Steve was there though - apparently it was interesting. Will try to get him to post...

 

[Graeme]

That'd be brilliant, Kat, by the way how are things? I've managed to find some more papers for my dissertation! Printing one off about the Bioluminescence in Stauroteuthis styrensis!

Graeme

 

[Taollan]

The suspense is killing me...however in the mean time I have found an article that deals somewhat with this...

Pakard, A., H. E. Karlsen and O. Sand. 1990. Low frequency hearing in cephalopods. J. Comp. Physiol. A 166: 501–505.

In this they found that Sepia officinalis, Octopus vulgaris and Luligo vulgaris were able to respond to a sound between 1 to 100 Hz. (they trained the poor critters to associate it with electrical shock. It seems positive reinforcement would have been... more humane... ) This is would be a much lower frequency than clicking rocks together..