Suction Disks; Anatomy and Function

[skywindsurfer]

While handling my GPO this afternoon I noticed that there is a small hole at the center of each suction disk. When I touch the disks, what appears to be a valve like disk below the hole pulls inwards, allowing the hole to open up. I took a rough picture of it but I can't post it right now. I would've taken a video for better clarity but it was hard enough to get the picture. I think I have an idea as to the purpose of this hole, but could anyone tell me more about it and its function?

[SabrinaR]

I'm sorry you have what now?

[skywindsurfer]

I must apologize but I do not understand your question.

[SabrinaR]

While handling my GPO

This is the confusing part. Please clarify.

[SabrinaR]

Ah I remember you work at an aquarium yes?

[skywindsurfer]

I care for a GPO at work.

[skywindsurfer]

That's right. Sorry for the confusion.

[Nancy]

You're fortunate to be able to care for a GPO. Does it interact much? Some of them seem to.

Nancy

[Green_Tree]

If i understood what you were describing correctly, as a valve-like disc below the hole pulling away from the hole when it wants to attach. Then it sounds to me like a plausible hypothesis for how exactly they are able to create suction on the arms so freely. But once again this is just my guess by what I think you were describing so i could be completely wrong.

[tonmo]

Fwiw, that's what I thought too. Makes sense to me.

What would be interesting would be to discern voluntary vs involuntary movement, which in itself has its own meaning when it comes to octopuses.

[cuttlegirl]

I didn't have a lot of time to search, but I did find this article.

http://jeb.biologists.org/cgi/reprint/157/1/257.pdf

[skywindsurfer]

You're fortunate to be able to care for a GPO. Does it interact much? Some of them seem to.

Nancy

I've had two so far and both were/are very interactive. I'll try to post some pictures and videos tonight, but no promises. I can say this though, the one we have now is about half grown and already strong enough to pull my shoulder out of socket. Not the best pet for a small person lol.

[skywindsurfer]

It makes sense that this part of thr disk could be used like a diaphram to create suction, but could it also play a role in sensory perception?

[Green_Tree]

Well if you accept the assumption that that hole has a diaphram behind it then it would be safe to say that when the suckers attach they bring in a small amount of water. Maybe there are sensory organs inside that function in much the same way as taste buds because it seems to me that they have to be able to taste or smell in some fashion since Iggy always gets active when i put mysis and brine shrimp in the tank and she is way back in her den where she could not see said shrimp.

[skywindsurfer]

Cephalopods do have organs somewhere inside either their mantel or buccal mass(spelling) that allows them to detect the "scent" of their prey. They also have the ability to "taste" via their suction disks.

[Green_Tree]

I didn't have a lot of time to search, but I did find this article.

http://jeb.biologists.org/cgi/reprint/157/1/257.pdf

Wow... I have not even made it all the way through that yet but lots of good information there.... also could be hard to read if you dont understand the technical jargon.

[skywindsurfer]

http://www.youtube.com/watch?v=5-GX955gtuc

[skywindsurfer]

http://www.youtube.com/watch?v=YRHN2vTD6Vg

[skywindsurfer]

http://www.youtube.com/watch?v=M6UpUmVarmg

[skywindsurfer]

http://www.youtube.com/watch?v=4caPONmhlto

[skywindsurfer]

http://www.youtube.com/watch?v=Jv3JT6yPRdA

[SabrinaR]

OMGoodness! Thats amazing! How big are they? What size tank do yall keep them in? Wow... Just WOW.

[skywindsurfer]

Lmao. And que the questions.

[skywindsurfer]

Our last one reached a length of roughly 5' relaxed arm tip to arm tip. We keep them in a rectangular exhibit aproximately 1,000 gallons. Which in my opinion is far too small.

[SabrinaR]

I dream of having a large tank able to handle such a beautiful animal! We were going to build a 1000 gallon tank down stairs but our kids are so little (not a good idea to have kids alone with large bodies of water) and in truth I told him I would much rather wait till we have a 1 story house so I can have a fish room where I can spend all day. I would love to be able to keep a GPO but I couldnt imagine the expense of running all of the equipment needed to run a tank big enough for it. Maybe when the kids are out of college. :tentacle:

:roflmao: A girl can dream.

[SabrinaR]

As far as it being to small... depending on the demintions... I dont think it would be to small. I think it comes down to this... Aquariums only have so much space and while it would be great to have a long and deep 10000 gallon tank for one GPO the cost of up keep just really isnt do able. So they do what most people do. They make the best of what they have so the public can view these wonderful animals.

[skywindsurfer]

lol well the bare minimum requirents would only be expensive at first ie the tank and chiller. The only problem is you need water near 50F and that makes weekly water changes dangerous for the animal if you don't have a seperate vat with a second chiller. You could still do the same thing with an O. Cyanea. They would be much easier to keep. I am actually building a large system between 3,000 & 5,000 gallons when we move. It will take up the entire room floor to about four feet high. All four walls and floor concrete with a narrow viewing panel near the door with everything internal.

[DWhatley]

I believe Dr. Martin Wells was the first to prove chemical reception in octopus suckers. After a very quick google, I found this article (http://www.scholarpedia.org/article/Tactile_sensing_in_the_octopus)that may help answer some of your questions but looking for key words with his name should bring up many more articles.

[skywindsurfer]

As far as it being to small... depending on the demintions... I dont think it would be to small. I think it comes down to this... Aquariums only have so much space and while it would be great to have a long and deep 10000 gallon tank for one GPO the cost of up keep just really isnt do able. So they do what most people do. They make the best of what they have so the public can view these wonderful animals.

We have tanks large enough just have different ideas for them. The tank really is too small because when these animals are fully grown they will span the entire length and the width is even less. I agree about the cost but I truly feel that if you cannot provide the a suitable habitat for an animal then you shouldn't have them. Public or not.

[skywindsurfer]

Thanks alot D and Cuttlegirl. When ever my work and how life slow down I'll have to take a look at those articles.

[Stavros]

Cool videos!

You may want to read this article on sucker morphology (http://icb.oxfordjournals.org/content/42/6/1146.full.pdf+html):

Let me know if you don't have access to it and I can send it via e-mail.

[skywindsurfer]

Awesome, thanks Starvos. I'll let you know.

[Lmecher]

Wow, have you ever been bitten? That last video looked kind of scarey. Thanks for sharing that.

[skywindsurfer]

I have never beenbitten by any cephalopod. Though I've always been curious of how it would feel.

[Lmecher]

I was just reading through one of your journals. You put on diving gloves while feeding Bubbles because you were worried about being bitten. (I completely understand the concern.) It just struck me as funny because in the videos you are handleing that enormous GPO and Bubbles is so tiny. :lol:
You privileged to work with such an amazing animal. Thank you for sharing, your videos are captivating. I enjoyed them :grin:

[skywindsurfer]

I was just reading through one of your journals. You put on diving gloves while feeding Bubbles because you were worried about being bitten. (I completely understand the concern.) It just struck me as funny because in the videos you are handleing that enormous GPO and Bubbles is so tiny. :lol:

Ya, but my GPO's arms are almost 3' long where as my hummelincki's are maybe one. There is less of a margin for error there. They both try to bite me though. Besides, don't underestimate the little guy lol.


You privileged to work with such an amazing animal. Thank you for sharing, your videos are captivating. I enjoyed them :grin:

Thanks for the compliment. I'll be posting another video that I took a day or so ago either tonight or tomorrow if your interested.

[Lmecher]

Yes I am, will be looking forward to it :popcorn:

[skywindsurfer]

Due to technical issues I haven't been able to download the video yet.

[skywindsurfer]

http://www.youtube.com/watch?v=mMpV00lheVE

[Lmecher]

That was fantastic :grin: he really wants out huh? I bet you could keep that up all day long. You get an arm in, another comes out. He sure looks friendly accepting petting. What a wonderful big fella. It was worth waiting for.
Again, thanks!

[skywindsurfer]

Everytime I open the lid he's up there clambering to escape. Ya I could do it all day if I didn't have to worry about loosing my job lol. I think the friendliness is a rouse. I know he secretly wants to eat me lol. Every other animal that I interact with in that place either attempts or succedes in bitting me. Maybe I just taste good. During one of my dives I was bitten three times on the same hand in the same spot by our stingrays within the matter of one minute, and just after that a clown tang bit my ear. Any ways, I'm glad that everyone is enjoying these videos. Maybe we should change the name of this thread to "The Wonderful Adventures with GPO".

[Lmecher]

Really I was under the impression that stingray's didn't bite (just pinch) since they have no teeth. We feed them occasionally at a LFS nearby. I just looked it up and found images, mostly bruising. I guess it must hurt to leave such a mark. You have very interesting job. :grin:

[skywindsurfer]

I can assure you that they do bite, and do have tooth like structures. Their jaws are designed more like two solid grinding units to crush their prey which generally consists of small crustaceans and mollusks, but some species have little spikes/nobs that can tear flesh. Some are gentle about being hand fed, but these can get rather aggressive not only with the divers, but with each other during the feedings.

[Tintenfisch]

The big stingrays (short-tailed and long-tailed, Dasyatis spp.) at Kelly Tarlton's (aquarium in Auckland) were definitely the ones we had to watch out for while doing the shark feeds. At more than 2m (6') wingspan and ~250kg weight (~550 lbs), a bite from them could leave a bruise easily the size of your head (and sometimes ON your head). They had learned that the more they bit, the faster they got fed, so would come in chomping as soon as divers got into the tank. Their favorite trick was to smash the divers up against the inside of the glass tunnel... the public found this enormously funny and rarely noticed the tears trickling down inside the mask. :wink:

[skywindsurfer]

Suddenly my stingrays don't seem so bad, though I'd be very happy to wrestle with your animals. : )

[Stavros]

Some really nice videos you have in this thread. What happened to it?

[Level_Head]

Here's another on the structure of octopus suckers, showing the purpose of that hole, with nice photos:

http://www.bio.unc.edu/faculty/kier/lab/pdf/Kier_Smith_2002.pdf

[DWhatley]

Thanks LH, I am supposed to be doing something else tonight so I have not read the paper but I did create a new "stuck" thread now at the top of this forum called Parts is Parts ... :grin: and know you likely have a bevy of articles I could put in links there :sagrin: You can PM me with any that come to mind (looking for specific body parts rather than whole anatomy) to add to the initial post or just add at will to the thread.