BHB gives info on some scaleless concerns

[anatess]

he downplayed the heat pit issue a little bit, yeah they probarbly sense heat, but its not directional anymore.

I haven't heard this one. Do you have a source?

[zeion97]

The scaleless was amazing to hold none the less. I saw no problem with it.. It moved like any of my other BP's just felt...weird. We just have to wait and see what the future holds.

[anatess]

I haven't heard this one. Do you have a source?

Let me repeat my question because it did not get addressed... who/where/when did anybody say that the scaleless ball pythons lack directional heat sensing due to the absence of pits?

[Pythonfriend]

Let me repeat my question because it did not get addressed... who/where/when did anybody say that the scaleless ball pythons lack directional heat sensing due to the absence of pits?

thats basic physics and geometry, based on the fact that any kind of skin or flesh is intransparent to infrared, even otherwise transparent eyeballs are intransparent to it.

and ill let Richard Dawkins explain the geometry issue:
http://www.youtube.com/watch?v=lEKyqIJkuDQ (of course the part where the lens comes in no longer applies to heat pits; the lens would be intransparent to infrared so the pit has to stay open.)

and a physics article about it:
http://phys.org/news76249412.html



you can find many more articles that mention the importance of the geometry of the pit and explaining that the snake figures out the direction by feeling which parts of the pit heat up and which dont. you can find it in physics, biology and herpetology articles.

[Xaila]

thats basic physics and geometry, based on the fact that any kind of skin or flesh is intransparent to infrared, even otherwise transparent eyeballs are intransparent to it.

and ill let Richard Dawkins explain the geometry issue:
http://www.youtube.com/watch?v=lEKyqIJkuDQ (of course the part where the lens comes in no longer applies to heat pits; the lens would be intransparent to infrared so the pit has to stay open.)

and a physics article about it:
http://phys.org/news76249412.html



you can find many more articles that mention the importance of the geometry of the pit and explaining that the snake figures out the direction by feeling which parts of the pit heat up and which dont. you can find it in physics, biology and herpetology articles.

I've actually been able to find precious little about the pit organs of boas and pythons, which are a little bit different from pit vipers. The idea is general the same though, IIRC. It does make me wonder how scaleless rattlesnakes have fared though.

[anatess]

thats basic physics and geometry, based on the fact that any kind of skin or flesh is intransparent to infrared, even otherwise transparent eyeballs are intransparent to it.

and ill let Richard Dawkins explain the geometry issue:
http://www.youtube.com/watch?v=lEKyqIJkuDQ (of course the part where the lens comes in no longer applies to heat pits; the lens would be intransparent to infrared so the pit has to stay open.)

and a physics article about it:
http://phys.org/news76249412.html



you can find many more articles that mention the importance of the geometry of the pit and explaining that the snake figures out the direction by feeling which parts of the pit heat up and which dont. you can find it in physics, biology and herpetology articles.

I completely understand how pit organs work.

What I don't understand is how you run with the conclusion that just because the beta-keratin layer on a scaleless ball python is thin (it's not completely absent, hence it still sheds) it somehow loses its directional heat sensing capability.

Find this article in your college library:
Campbell, A. L., T. J. Bunning, M. O. Stone, D. Church, and M. S. Grace. 1999. Surface ultrastructure of pit organ, spectacle, and non pit organ epidermis of infrared imaging boid snakes: a scanning probe and scanning electron microscopy study. Journal of Structural Biology 126: 105-120.

It posits that boids don't just rely on the pit holes, they have micropits that are like pores that reconstruct infrared signals into an image. It supports the claim in the article you linked to that the 2 pit holes in pit vipers are more limited than say, a ball python that has several labial pits. If the beta keratin layer was so thin that a maximum array of signals hit the micropits, then you get better infrared vision. But that's just my opinion.

The bread of this butter can be evidenced by the ability of the scaleless ball python to find the head of the rat. Well, it would be great if Brian would actually give it a live one in the dark so we can see if it can track the rat and strike it on the back of the head. I'm betting that it can.

[Pythonfriend]

I completely understand how pit organs work.

What I don't understand is how you run with the conclusion that just because the beta-keratin layer on a scaleless ball python is thin (it's not completely absent, hence it still sheds) it somehow loses its directional heat sensing capability.

Find this article in your college library:
Campbell, A. L., T. J. Bunning, M. O. Stone, D. Church, and M. S. Grace. 1999. Surface ultrastructure of pit organ, spectacle, and non pit organ epidermis of infrared imaging boid snakes: a scanning probe and scanning electron microscopy study. Journal of Structural Biology 126: 105-120.

It posits that boids don't just rely on the pit holes, they have micropits that are like pores that reconstruct infrared signals into an image. It supports the claim in the article you linked to that the 2 pit holes in pit vipers are more limited than say, a ball python that has several labial pits. If the beta keratin layer was so thin that a maximum array of signals hit the micropits, then you get better infrared vision. But that's just my opinion.

The bread of this butter can be evidenced by the ability of the scaleless ball python to find the head of the rat. Well, it would be great if Brian would actually give it a live one in the dark so we can see if it can track the rat and strike it on the back of the head. I'm betting that it can.

I only managed to get the abstract of the paper, but the abstract in no way says that these micropits provide any directional heat sensing. they merely amplify signal strength by concentrating the thermal effect of the infrared radiation to those points where the heat-detecting cells are. The abstract says: "Pit organ micropits averaged 319 nm in diameter and 46 nm in depth and were spaced an average of 808 nm from each other". So its not deep enough to be a cup camera, and the size of a single cell is comparatively too large, so i just dont see how it could provide directional information.

Heat pits are between one and a few millimeters in size. The micropits you mention are too shallow, and also 319 nanometers is equal to 0.000319 millimeters. Thats off by like 3 orders of magnitude. I say these structures merely make existing heat pits more effective, but do not have the right size or geometry to provide directional sensing on their own. That is, if these structures even exist in a scaleless BP.

finding the head seems to be more of a tactile task.

[anatess]

I only managed to get the abstract of the paper, but the abstract in no way says that these micropits provide any directional heat sensing. they merely amplify signal strength by concentrating the thermal effect of the infrared radiation to those points where the heat-detecting cells are. The abstract says: "Pit organ micropits averaged 319 nm in diameter and 46 nm in depth and were spaced an average of 808 nm from each other". So its not deep enough to be a cup camera, and the size of a single cell is comparatively too large, so i just dont see how it could provide directional information.

Heat pits are between one and a few millimeters in size. The micropits you mention are too shallow, and also 319 nanometers is equal to 0.000319 millimeters. Thats off by like 3 orders of magnitude. I say these structures merely make existing heat pits more effective, but do not have the right size or geometry to provide directional sensing on their own. That is, if these structures even exist in a scaleless BP.

finding the head seems to be more of a tactile task.

Do you have access to any of the college libraries? It would be great if you can peruse the entire article. The paper goes more in depth on the studied functions of micropits. And, the micropits don't just receive signals from the pit holes either as they are found all over the head and body of the boid.

Finding the head in the dark tells us a lot about the infrared image the snake is receiving as striking in the general direction of the rat may not tell you what the snake "sees" but more what the snake hears/feels. So, if it can still target the head of the rat with that thin beta-keratin layer over the pit membrane, then it's an indicator that the absence of the visually-normal pit holes is not in any way providing a handicap.

[anatess]

P.S.
From what I know of pits, they do not function like photo receptors on a camera lens because they don't function with light. Instead they function through heat. So it is this heating of the pit holes that trigger nerve signals. Now, whether these nerves rely solely on the thickness of the scale around it and the size of the hole or if it still functions with a variation of thickness and hole size is the question (do the scaleless still have the labial holes?). Not one scholarly article in structrual biology addresses it. Probably because Brian is the first guy that figured out how to produce one.

You know, I'm going to shoot Brian an email and see if he can run this experiment with his scaleless. It would be a great science project for my kid. This could also provide very critical knowledge on the function of the labial pits because, even to today, that's still an evolving science.

[Pythonfriend]

Do you have access to any of the college libraries? It would be great if you can peruse the entire article. The paper goes more in depth on the studied functions of micropits. And, the micropits don't just receive signals from the pit holes either as they are found all over the head and body of the boid.

Finding the head in the dark tells us a lot about the infrared image the snake is receiving as striking in the general direction of the rat may not tell you what the snake "sees" but more what the snake hears/feels. So, if it can still target the head of the rat with that thin beta-keratin layer over the pit membrane, then it's an indicator that the absence of the visually-normal pit holes is not in any way providing a handicap.

I almost feel a little bad when i have to crush an argument so cruelly. But then, its how we learn... happens to me as well.

one fact blows your argument out of the water. while it is true that in living rhodents the head is much warmer than the rest of the body, and gives off more heat, that is not true for frozen thawed rats. and BPs manage to find the head on a frozen thawed. and a frozen thawed is by the very fact of getting killed, then frozen, then thawed, totally uniform in temperature. so it cannot be true.

then, your other comment.... yeah, they function through heat. heat moves at a certain velocity through solid materials. so a large object will reach thermal equilibrium slower than a small one. like, in a proper heat pit, some areas can be warmer than others because the long distances cause heatr transfer to be slow. now listen: on the nanoscale that all goes to hell because the pits the article describes will reach thermal equilibrium around 3000 times faster. getting a differentiated signal would require the receptors and neurons and the BPs brain to be 3000 times faster. (and i already mentioned that the geometry of these small things just is not right).

http://www.youtube.com/watch?v=eQR1r1KTjaE


*WARNING* breakig bad spoiler in following link *WARNING*
http://www.youtube.com/watch?v=JDQOvzFetxs