Why Must Some Sharks Remain In Motion And Not Others?
#1
Posted 30 June 2007 - 11:11 PM
I noticed that there appeared to be some type of sensor or moveable flap above and to the rear of the eye. It was only about 1/8th of an inch/square.
Consulting my ID books I learned that this is called a Spiracle. It's present in some sharks and Rays/Skates.
As we know some sharks must be in constant motion in order to move water through the gills to oxygenate the shark's blood. Some sharks don't have to keep moving. This much I knew but I didn't know why some didn't have to keep moving. Some have a Spiracle and some don't (there may be other reasons as well).
When the Dogfish decides to quit moving and rest the Spiracles open and force water through the gills.
So through my curiousity I learned what that flap that I observed was and also learned something that I hadn't expected...why sharks that are able to remain at rest are able to remain at rest.
Hopefully, someone else will find this interesting
#2
Posted 30 June 2007 - 11:36 PM
I was watching David Suzuki's The Nature of Things a short while ago and the topic was Wild Caribbean: Reefs and Wrecks. Nursesharks were mentioned as being one of, or the only, shark that is able to remain still for prolonged periods of time. (I guess based on your research, they're not the only ones though...)
#3
Posted 01 July 2007 - 12:21 AM
I will have to do a bit more research on the Dogfish.
Thanks for sharing.
Formerly known as gis_gal and name tattoo'd for a small bribe!
#4
Posted 01 July 2007 - 01:10 AM
Interesting!
I was watching David Suzuki's The Nature of Things a short while ago and the topic was Wild Caribbean: Reefs and Wrecks. Nursesharks were mentioned as being one of, or the only, shark that is able to remain still for prolonged periods of time. (I guess based on your research, they're not the only ones though...)
I don't know how long prolonged is but in addition to Dogfish I have also seen Sixgill sharks resting on the bottom although it's usually the smaller ones in the 6 foot range.
Edited by gcbryan, 01 July 2007 - 01:41 AM.
#5
Posted 01 July 2007 - 02:32 AM
#6
Posted 01 July 2007 - 06:06 AM
I had a particularly good view of a Couch Potato (Large) the other day.
I noticed that there appeared to be some type of TV remote in one hand and chips in the other
As we know some humans must be in constant motion in order to move o2 through the gills to oxygenate the blood.
Apparently Couch Potatos move air by yelling at the TV
So through my curiousity I learned what that remote that I observed was and also learned something that I hadn't expected...why humans that are able to remain at rest are able to remain at rest.
Hopefully, someone else will find this interesting
By all that is wet, I do hereby swear, (politely), and attest, upon pain of never diving again, (real or imagined), that I understand and affirm, that I agree to the above.
_________________________________________(log in name signature)
Signed and Dated
#7
Posted 01 July 2007 - 08:53 AM
Why Must Some Humans Remain In Motion And Not Others?, The anwer is...
I had a particularly good view of a Couch Potato (Large) the other day.
I noticed that there appeared to be some type of TV remote in one hand and chips in the other
As we know some humans must be in constant motion in order to move o2 through the gills to oxygenate the blood.
Apparently Couch Potatos move air by yelling at the TV
So through my curiousity I learned what that remote that I observed was and also learned something that I hadn't expected...why humans that are able to remain at rest are able to remain at rest.
Hopefully, someone else will find this interesting
There's got to be a connection here. Maybe some sharks are watching too much T.V.
Seriously though, I'm having some difficulty visualizing the little flap that GCBRYAN is talking about.
If anyone can get a picture of it, post it.
When you make fish laugh, they can't bite you.
#8
Posted 01 July 2007 - 12:34 PM
There's got to be a connection here. Maybe some sharks are watching too much T.V.
Seriously though, I'm having some difficulty visualizing the little flap that GCBRYAN is talking about.
If anyone can get a picture of it, post it.
I don't see an option to attach pictures but if you go to:
http://www.elasmodiv.....Quadra 87.jpg
you will see a slit slightly above and anterior to the eye. You might need to copy the picture and enlarge it a bit.
Edited by gcbryan, 01 July 2007 - 12:35 PM.
#9
Posted 01 July 2007 - 12:36 PM
Why Must Some Humans Remain In Motion And Not Others?, The anwer is...
I had a particularly good view of a Couch Potato (Large) the other day.
I noticed that there appeared to be some type of TV remote in one hand and chips in the other
As we know some humans must be in constant motion in order to move o2 through the gills to oxygenate the blood.
Apparently Couch Potatos move air by yelling at the TV
So through my curiousity I learned what that remote that I observed was and also learned something that I hadn't expected...why humans that are able to remain at rest are able to remain at rest.
Hopefully, someone else will find this interesting
I like your writting style!
#10
Posted 02 July 2007 - 06:26 AM
Why Must Some Humans Remain In Motion And Not Others?, The anwer is...
I had a particularly good view of a Couch Potato (Large) the other day.
I noticed that there appeared to be some type of TV remote in one hand and chips in the other
As we know some humans must be in constant motion in order to move o2 through the gills to oxygenate the blood.
Apparently Couch Potatos move air by yelling at the TV
So through my curiousity I learned what that remote that I observed was and also learned something that I hadn't expected...why humans that are able to remain at rest are able to remain at rest.
Hopefully, someone else will find this interesting
I like your writting style!
That's the CDNN school of writing, take someone else's work, change a word and take credit for the whole story!
By all that is wet, I do hereby swear, (politely), and attest, upon pain of never diving again, (real or imagined), that I understand and affirm, that I agree to the above.
_________________________________________(log in name signature)
Signed and Dated
#11
Posted 02 July 2007 - 04:19 PM
At one time I devoured everything I could on sharks. I took a few years off for the Army, then I got sidetracked with herpetology. Now I am back full on with sharks and marine biology, and there is so much new stuff out there.
Well, I learned something new today...
"Winter is not a season, it's an occupation." -Sinclair Lewis
Meet Pearl and Opal, the new shark rays in Adventure Aquarium.
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