Question about deep-sea ceph's

[Feelers]

Do they need pressure adaptations?

To them isnt swimming at 50,000 leagues just the same as swimming a 5m?
I would have geussed that the only adaptations would deal with visibilty/temperature/ect.

 

[Fujisawas Sake]

As far as osmotic pressures I would have to say no, but only becuase all aquatic molluscs are osmoconformers. As far as physical pressures... That's a very good question. Most pressure-related physical problems arise from blood-gas, air bladder, and bone issues. Since no cephs have none, I can't think of any pressure adaptations they could have.

HOWEVER, as Steve O' points out, rapid change in pressure is probably fatal to most deep-sea cephs, so somthing has to happen tissue-wise. I often wonder if Sperm Whales use this to their advantage while hunting?

 

[Feelers]

Perhaps they get "the bends" kind of, maybe with ammonia (not nitrogen) forming bubbles in the tissues with the sudden change to the equilibrium?

 

[Fujisawas Sake]

I don't think ammonia goes to gas that easily though. That is an interesting thought. Hmm... Steve O' might have an idea.

I wonder what proportion of deep-sea cephs are considered "ammoniac"?

John

 

[Feelers]

I did a project on "the buoyancy mechanisms of midwater cephalopods" lol, and I think that the ones that dont use straight ammonia use ammonia tacked onto other molecules such as methylamine.

The "majority of squid families" use the straight Na for NH4 exhange I believe.

 

[main_board]

I wonder if they have different consentrations of cholesterol in their membranes as they are directly exposed to very very cold temperatures but manage to stay relatively ductile and flexible. Would pressure come into effect here as well? Hmmm... Good question!

Cheers!

 

[Graeme]

In English.....

J

erm........
Well, I can do English, but as far as a summary....

I did find out stuff about generic cellular membrane adaptations, such as homeoviscosity, as well as a theory that animals can use changes in their cell membranes to indicate pressure change, and thus depth. Got me thinking- this'd be a good way for animals who engage in nightly vertical migration to be able to tell which way they're going. If it's dark in the deep sae, and it's dark at the surface, then how is an animal going to tell which way it is travelling, unless it can tell if the pressure is lessening. I know that several ceph species do this vertical migration at night, I think to feed or spawn or something (maybe not spawn since most only spawn once) as well as other animals. Could this be right?

Graeme

 

[chrono_war01]

Referred this thread to my secondary school bio teacher and he said it was too hard for him to understand and that dwelling too long on these things would either make you go mad or your brains to melt.



There's this question nagging on my head, do cephs have some sort of organ in their body which tells the ceph which way is up? or do they sense the water pressure?

 

[um...]

Statoliths tell them which way is down. I assume that they're smart enough to subsequently compute which way is up. Being able to sense depth would be handy, though...

 

[chrono_war01]

Well, if they do have Statoliths, then assuming that they know how to use it would be logical, or else they would find themselves trying to get to the bottom of the ocean but ending up on a beach.

 

[monty]

Referred this thread to my secondary school bio teacher and he said it was too hard for him to understand and that dwelling too long on these things would either make you go mad or your brains to melt.

Are you sure he wasn't reading the "Who is this Cthulhu guy anyway?" thread?

And yeah, what um... said about statolith. It is a good question how cephs sense or estimate depth, which, I guess, could be pressure, temperature, light level, or dead reckoning.

 

[Fujisawas Sake]

Referred this thread to my secondary school bio teacher and he said it was too hard for him to understand and that dwelling too long on these things would either make you go mad or your brains to melt.

No offense to you Eric, but WHERE IN THE NAME OF ZEUS' LEFT TOE DO YOU ATTEND SCHOOL??? I mean, your teacher must be smoking the hard Humboldt County green to say something like that. I would show him a platapus skeleton and watch him suddenly revert to a quivering mass of frightened protoplasm! man, people bash the United States for having a bad school system but I NEVER had a teacher say that to me. Dude, get home schooled... or at least school your teacher.

There's this question nagging on my head, do cephs have some sort of organ in their body which tells the ceph which way is up? or do they sense the water pressure?

Well, gravitropism is by means of the statolith. I would like to know more about their pressure sensation though, because I would think its based on their sense of touch, like ours.

John

 

[Jean]

I would hazard a guess that the statoliths or at least the statocyst chamber would help with detecting pressure changes too (it is a fluid filled chamber...anyone who has had sinusitis while travelling at altitude knows about that!!!!). Plus some have a lateral line analog......a pressure sensor.

J

 

[Steve O'Shea]

.... people bash the United States for having a bad school system but I NEVER had a teacher say that to me. Dude, get home schooled... or at least school your teacher.

My science teacher told me and my folks at one of those parent-teacher thingies that I'd "never amount to anything because I was too tunnel visioned". That hurt more than anything anyone has ever said.

To a certain extent I understand where he was coming from, as to have a broader knowledge of a few things would certainly help matters. However, I never care to meet him again, and wonder how many others he destroyed creativity in!

 

[Graeme]

I got "advised strongly" not to take Biology as a Standard Grade subject when I was 13 or 14. I'm doing honours Zoology. Just goes to show you, don't always follow what you're told. If you can feel you can do it, you will!

Oh, and teachers know absolutely sweet FA out of their subject, and teach you sweet FA about hte subject

Graeme