# Scientific Inferences/Hypotheses on Pyramiding



## pzowt (Jul 18, 2012)

Everyone says that calcium is an imperative part of any tortoise's diet, right? And it should prevent pyramiding (alongside sufficient vitamin D3/UVB and fibre), right?
But if we know (or at least just suspect) that these should create smooth-shelled chelonians indefinitely (depending on the species' place of origin), why aren't ALL our tortoises smooth??

Assuming the not-so-smooth tortoise owners know and understand the exact requirements (that experts/professionals/enthusiast provide), why do some tortoises present pyramidal growth?

What my hypothesis is is that we have _something_ wrong in our understanding of tortoise chemistry. I'm thinking along the lines of the calcium absorption.

From my understanding of Tom's past experiments, moisture has a significant impact on the tortoise's overall shell-shape (I'm pretty much accepting this as gospel haha). But any who...

To be exact on my hypothesis, I believe we provide too much calcium! Knowing that calcium is water-soluble, I'm inferring that when we provide too much calcium in our tortoise's diet, the added moisture and baths will provide enough water to flush out any excess calcium (which I am going to assume causes pyramiding). 

I may be wrong, however. (I'm no biochem specialist haha). Where my hypothesis falls is when UVB and Vitamin D3 is introduced into the body. A good owner knows to provide enough light/supplements so that calcium build-up in the system won't hurt...

I'm very curious to find an answer! Anyone have any suggestions or theories or anything??

ALSO! (I'm starting to think out loud aha ) In the wild, tortoises may not find sufficient calcium in their environment...but they're almost always smooth-shelled. They'll undoubtedly get good amounts of UVB/D3, but get varying levels of calcium... Hmm. 

Any added information???
Please don't be afraid to hypothesize or provide personal experiences!


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## ascott (Jul 18, 2012)

Ok, you asked...

I believe that calcium is only a part of the cycle of the tortoise (which also includes his shell)...I think we as humans try to out think everything...just what we do...I believe that if we would stand back and observe a tortoise in the wild--we would see a tort that is ever versatile...ever searching for the next bite (exercising and sun exposure), seeking out shade (resting in the fresh air, shell having opportunity to dry and be healthy so no funky stuff growing), retreating to a darker cooler place (rest and mild humidity and shelter from night predators)...

Now, _I do not believe_ that we will ever ever ever be able to completely understand the food benefits from when they are out for the entire day (and I don't mean out in the sun, but rather out time from when they wake to set out for their day and when they retreat for the night) taking a bite or two from about a hundred different plants....how much calcium do they get? well, I know that arid species are usually surrounded by dry/dryer conditions which means dry soil plants have a high calcium content in comparison to wet/constantly wetter environments which do not have high calcium contents...so they absolutely have to be designed in different ways based on where they live, the food available and the quantity of food required to allow their body to perform at its peak....

Humidity does play a role, no doubt---however, I do not believe it is a full proof absolute remedy to a healthy bone structure under the scutes...I do believe that it renders the scutes a bit more pliable during growth of the bone...but bone is something that has to develop strong and solid --and in this case the scutes being hydrated enough is key in following the bone structure growth....this is where I believe sun, food, amount of food offered on a daily basis and exercise is so important...I will not ever be able to tell which one is the main catalyst for a smooth healthy shell, and I don't believe there is any single one...so I strive to offer the best I can of each...then let the tort be a tort....


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## pzowt (Jul 18, 2012)

Excellent post, Ascott!
I hadn't taken into thought the specific environments in the different places of origin! Neither did I think about a wild tortoise's presumed day of activity.
hmmm
Let's specify this a little bit by focusing on an african species (since I just obtained a new little leopard! woo!). Leopards seem to pyramid the most (from what I've seen)... and sometimes even in the wild. Their dry environment, according to what you said (which does make sense to me), should have calcium-fortified (haha) plants growing plentifully. This calcium ( and D3) presumably adds to the proper growth of a leopard's bone structure...
(I'm thinking out loud again)
and with your theory of humidity, sufficient moisture seems to provide the flexibility of shell-shape (scutes) during growth.... hmmm
This makes a lot of sense to me now!


Now, to summarize a little bit (in equation form!! wooo!!!)

Smooth Shells
= (Calcium + UVB/D3) + Water
= (Growing bones) + Humidity

But what about fibre? Why does fibre come up so often in tortoise care sheets? Or exercise??


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## ascott (Jul 18, 2012)

also, in my own speculation times, I wonder, the arid species would encounter times of extreme times (years of drought in some cases) so to me that would open the door of the possibility of a tort running too dry during the first few years of its life...and if there were drought years the plant growth of course would be affected and therefore the torts would not eat the calcium rich foods normally available (as the plants go dormant for years in arid environments simply to sustain a morsel of root system to lay in wait for rain)...yet the sun is bright and shining which is a part of what a tort needs but if the nutrition is not good and the tort is not eating properly then I would think that the growth would be affected to the bone under the scutes, right? Here is why---if there are periods of not enough calcium intake (not proper food available) then the body will use what it has --which in turn can begin to cause pyramiding due to the body feeding essentially off of itself...now, understand--this is simply what I have thought of and have absolutely no scientific mumbo jumbo to support my way of thinking....only thing I have is connect the dot science...1 plus 1, usually equals 2----


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## pzowt (Jul 18, 2012)

Yes! 1 plus 1 usually equals 2 in connect the dot science haha
That is my scientific method as well 

So what you're saying is that pure (un)luck in wild environments would be the cause of any (if at all) shell deformities? That sounds good to me! (Along with the fact that native humans can/do/have released human-induced pyramiding haha)

All seems understandable

Now what's your take on exercise and fibre??


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## ascott (Jul 18, 2012)

Exercise=essential to the mental well being, essential to the development of muscle, essential to the digestive system, essential to eating.

Fibre= essential to digestive system, essential part of alot of tortoise species diet and supplies the bulk to satisfy feeding needs and hunger desires.


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## dmmj (Jul 18, 2012)

Calcium does not provide a huge role in preventing pyramiding besides growing healthy bones and shells. The main reason why a lot of us stress humidity is because is sort of provides a lubricant for the shell, allowing it to grow easier? smoother? I have seen a picture of a leopard in a game type preserve that was pyramided, but not knowing it's history I can't say if it was a wild one or one that maybe was turned in.


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## Tom (Jul 18, 2012)

pzowt said:


> Everyone says that calcium is an imperative part of any tortoise's diet, right? And it should prevent pyramiding (alongside sufficient vitamin D3/UVB and fibre), right?



The answer to number one is a big "maybe". Depends on species, age, sex, diet, etc...

The answer to number two is a definitive "no". Whether a tortoise gets a calcium supplement every day, or never at all, will have no effect on whether or not it pyramids.

The role of humidity, as well as temps, diet, exercise, calcium and sunshine, will likely be something that we research and learn about for many more years. I'm constantly learning and observing more. Dean and I are running a comparison of two different methods on sulcatas from the same group and age right now. Neal is raising smooth leopards in relatively dry conditions, and has told me that he thinks hydration, and not so much humidity, is a big key. Humidity may simply be a way to stave off dehydration through respiration in an artificial dry environment. Also factor in the habits/adaptations of different species. Sulcatas burrow and stay underground. Leopards hide, but not necessarily underground in damp burrows... Much to consider. Throw in all the varieties of Testudo , and the redfoots, and we can throw the sweeping generalities out the window...

To answer your specific question: No. I don't think we offer too much calcium, and no, I don't think it has anything to do with pyramiding. Many of the worst cases of pyramiding are caused by relatively ignorant keepers, who never even offered a calcium supplement, while offering a very calcium poor diet at the same time. In these cases, it is clear that an excess of calcium supplementation was NOT the cause, or even a contributing factor for horrible pyramiding.


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## Arizona Sulcata (Jul 18, 2012)

Tom said:


> The answer to number one is a big "maybe". Depends on species, age, sex, diet, etc...
> 
> The answer to number two is a definitive "no". Whether a tortoise gets a calcium supplement every day, or never at all, will have no effect on whether or not it pyramids.
> 
> ...



Agree 100%.


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## ascott (Jul 18, 2012)

> I'm inferring that when we provide too much calcium in our tortoise's diet, _the added moisture and baths will provide enough water to flush out any excess calcium (which I am going to assume causes pyramiding).
> _



I do not believe the point of this comment was saying that giving too much calcium is the cause of pyramiding, but if folks offer calcium supplements in large volumes then wouldn't large amounts of humidity and hydration wash away or decrease the calcium levels by the tort expelling it quicker than if high levels of humidity and hydration where not offered---hence removing the added calcium some folks offer.....which in turn means a potential of calcium deficiency...at least this is what I understood this to mean...


Calcium plays a tremendous role in so many factors, in addition to a healthy shell formation...

http://africantortoise.com/leopard.pdf


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## Jacqui (Jul 19, 2012)

ascott said:


> Humidity does play a role, no doubt---however, I do not believe it is a full proof absolute remedy to a healthy bone structure under the scutes...I do believe that it renders the scutes a bit more pliable during growth of the bone...but bone is something that has to develop strong and solid --and in this case the scutes being hydrated enough is key in following the bone structure growth....this is where I believe sun, food, amount of food offered on a daily basis and exercise is so important...I will not ever be able to tell which one is the main catalyst for a smooth healthy shell, and I don't believe there is any single one...so I strive to offer the best I can of each...then let the tort be a tort....



Well said!


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## CactusVinnie (Jul 19, 2012)

As said before, increased moisture makes the scutes more flexible and so the contraction pressure decreases-> that logically leads to- at least theoretically- a more smooth appearance. 

We should not yet forget that pyramiding is much more than rigid, scorched tough keratine scutes with obvious margins protruding a little... that's maybe due to extreme dryness, especially at very young tortoises... I have such a baby (not my production, received it that way) with such scutes- esp. vertebrals- but he's not pyramided in the sense we are talking about here... that I would say it was from a too dry environment. If I will have the time, I will post exemplifying pictures.

But pyramiding usually consists in serious INCREADSED THICKNESS of scutes due to keratine proliferation, in the detriment of the bony layer, that can't keep the same growth speed. *Lots of food* without the proper amount of *calcium* and sun/UVB naturally lead to a good amount of GROWTH, but no harmonious growth; even the "pyramids" are "growth", and need protein to be built.
That's why severe pyramiding cases came together with a collapsed carapace, because the lack of calcium to confere it resistance. 
So, lack of calcium is another important feature. I would say the most important factor.

I keep my baby tortoises on the dry side... practically, no soaking, although I spray with a hose for a few seconds every 4-5 days, mainly to make them get out of the hide, to have dinner in the late afternoon. Some times I spray directly on them, but only 1-2 seconds, very fast. They have growth but very good growth, despite the generally dryish conditions. 

Here I would say it's the difference: even if increased moisture makes the scutes more flexible and prevent "scute edging" (new term of mine , to be exemplified with pictures), it cannot prevent pyramiding, in the sense we generally define it. It is obvious that only the protein-feed keratine scutes will not became so deformed solely by lack of elasticity!! It is about *an abnormal thickness*, no matter how strong are the tensions generate by the drying keratine... these maybe exist, but they couldn't stop, neither explain the deficitar growth of the skeletal part-> collapsed carapace. No way! Saying that dry, rigid, brittle keratine lead to difformity is the same with saying that people in arid areas should have deformed fingers!

So, together with my babies example, I think that there can be very dry, but impecable carapace. Better than a flexible one attenuating tensions when water saturated, it is one already dry, made by strong well built keratine! The "overfeeding" situations, if good quality food (low protein, high fiber and calcium) provided, should translate in a good growth spurt as it happens even in habitat in favourable years- even 5 mm wide growth-lines!! Why not growing only by the vertical-> pyramiding? Because the bony layer was also well sustained and it grew in a harmonious way too, resulting in a good gain in dimensions and weigth. 

After some research on Spanish Graeca, A. Highfield found that is not much a difference in burrows/hides moisture level compared to the surroundings. Wich was DRY. 

The most pyramided species in natural habitat are hermanni- both Eastern and Western. Is it a coincidence to the fact that they are the only Eurotestudo, living in the less arid environments of all Testudo?? Europe, the only areal of T. hermanni, barely has some seasonal semiarid, and mostly not arid at all areas. Hermanni can get overfed some seasons, and they have incredible growth spurts, that cannot be synchronised with a good amount of calcium for a while. Especially if they eat snails (hermanni delicacy), the protein apport is huge, and they may slightly pyramide even in the wild.
As for moisture... the Balkans have enough of it... hermanni NEVER lives far of the forest, in fact it lives only nearby forests, and finding a moister hide in summer is simply resolved by retreating into the forest. Many Ibera do the same when near forest, but they live even in open prairies- Hermanni don't. 
So, how the most wild-pyramiding cases occur even in the "moister" Testudo habitat, if humidity matters that much??

I am referring only to Testudo genus, but I suppose it is generally the same for arid/semiarid tortoises too.


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## Tom (Jul 19, 2012)

Fabian, Raise a smooth sulcata or leopard that way and then lets talk. I've never done any Testudo sp. my way, and it appears you've never done any sulcatas or leopards your way. I think this is a case of apples and oranges. My comments above are colored by my frame of reference, which is raising sulcatas and leopards in Southern CA. I read Highfields T. gracea studies with great interest. I think most of the people who have raised both sulcatas and Testudo will agree that in most "mild" climates, that a Testudo sp. raised in a naturalistic outdoor enclosure will seldom pyramid, even if things are relatively dry. This is NOT the case for a sulcata or leopard in a dry climate. My current adults were raised primarily outside, similar to how you describe your set up, and they still pyramided substantially.


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## mctlong (Jul 19, 2012)

Fascinating thread, all very good arguments....hmm. 

So much to consider.


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## Madkins007 (Jul 19, 2012)

CactusVinnie said:


> (snip)
> 
> But pyramiding usually consists in serious INCREADSED THICKNESS of scutes due to keratine proliferation, in the detriment of the bony layer, that can't keep the same growth speed. (snip)



I have a shell of a red-footed tortoise at home with moderate pyramiding. The scutes are only paper-thick, but the bone has risen up under the mis-shapen scutes.



pzowt said:


> Everyone says that calcium is an imperative part of any tortoise's diet, right? And it should prevent pyramiding (alongside sufficient vitamin D3/UVB and fibre), right? (snip)
> 
> To be exact on my hypothesis, I believe we provide too much calcium! Knowing that calcium is water-soluble, I'm inferring that when we provide too much calcium in our tortoise's diet, the added moisture and baths will provide enough water to flush out any excess calcium (which I am going to assume causes pyramiding). (snip)



Offering calcium, by itself or in conjunction with D/3, etc. does not seem to be 'the' answer to pyramiding, and calcium is not water-soluble, although in a properly hydrated tortoise excess calcium is excreted in the feces.

The thing that I see pretty consistently in these discussions is that the tortoise shell is a pretty intricate 'dance' coordinating dietary issues, heat/humidity issues, and the balance of food/climate that each species experiences.

I sometimes wonder if there even IS an 'all in one' answer or if it boils down to doing a better job of recognizing and duplicating key elements of the native habitat?


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## chairman (Jul 19, 2012)

Are there any species other than tortoises/turtles that have keratin growing on bone without an intermediate layer or layers of skin/flesh?

My thought is that bone growth issues in shells are directly related to the lack of flesh, blood vessels, etc surrounding the bone. 

I don't think we'll know the mechanism until either a tortoise enthusiast hits the powerball and desires to spend a couple million on research, or a big pharmaceutical company can be convinced to spend millions studying pyramiding as a way to develop expensive drugs for human bone growth issues.


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## Tom (Jul 19, 2012)

Madkins007 said:


> The thing that I see pretty consistently in these discussions is that the tortoise shell is a pretty intricate 'dance' coordinating dietary issues, heat/humidity issues, and the balance of food/climate that each species experiences.
> 
> I sometimes wonder if there even IS an 'all in one' answer or if it boils down to doing a better job of recognizing and duplicating key elements of the native habitat?




With this I agree. It is clear, that there are differences between the species, as far as what is needed for proper growth.





chairman said:


> I don't think we'll know the mechanism until either a tortoise enthusiast hits the powerball and desires to spend a couple million on research, or a big pharmaceutical company can be convinced to spend millions studying pyramiding as a way to develop expensive drugs for human bone growth issues.



You are so right about this. Sad, but true.


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## CLMoss (Jul 19, 2012)

I find all of this information about pyramiding very interesting. But please help me understand the conflicting information regarding "Star Tortoises." Some believe that it is due to inbreeding & others believe it to be a survival mechanism (the ability to "right" themselves).



Here is something that I read at Star tortoise.net: 



2008 RFUK forum post, Andy Highfield (Tortoise Trust, UK) writes that he has seen hundreds of x-rays of pyramided tortoise shells, and he's never seen a pyramided tortoise that didn't have metabolic bone disease. Having said that, he states that this excludes Indian Star tortoises and African starred tortoises where conical scute formation is genetic. He then writes: "Despite the 'pyramid' or tent-like structure of the vertebral scutes on these, the bone density is entirely normal and no lesions are present."



I noticed that my SL Star tortoise (hatchling) had a growth spurt and did see her scutes have become more defined. It worries me because I am/was under the impression that I am doing everything right. Here is a recent photo of her, she is about 7 months when this photo was taken.



Thanks, any feedback is really welcomed.


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## Tom (Jul 19, 2012)

Sorry, I don't know stars.

But it is entirely possible to have pyramids without MBD in any species, depending on how you define MBD.


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## Madkins007 (Jul 19, 2012)

Tom said:


> Sorry, I don't know stars.
> 
> But it is entirely possible to have pyramids without MBD in any species, depending on how you define MBD.



Yeah, that is true- the term MBD is a catch-all phrase for many actual bone-related issues. Even though the most common is Nutritional Secondary Hyper-Parathyroidism (a dietary issue involving the balance of calcium, phosphorous, and vitamin D), there are a lot of other things under the umbrella.

Personally, since it does involve bone, and it indicates a problem of some sort, I would call it MBD, but that does carry a lot of stigma to it.


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## ascott (Jul 19, 2012)

> I sometimes wonder if there even IS an _'all in one'_ answer or if _it boils down to doing a better job_ of recognizing and duplicating _key elements of the native habitat_?



Perfect.


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## GeoTerraTestudo (Jul 19, 2012)

One thing we know that pyramiding is _not_, is this:







Okay, kidding aside, here are my thoughts on pyramiding in chelonians. Although humidity plays a role in proper carapace development, it's not the only factor or even the primary factor, because even omnivorous pond turtles can get pyramiding:






*Source:* http://aqualandpetsplus.com/Turtles, Misc II.htm
*Caption:* _"One-year-old red ear fed on a hamburger diet. Note the pyramiding."_

I think the ultimate cause is malnourishment leading to abnormal bone growth (a form of MBD). If an animal doesn't get the nutrition to which it's adapted, it's metabolism is going to be disrupted, and it's going to develop physiological and anatomical problems, such as shell deformity.

Tortoises appear to be more vulnerable to pyramiding, probably because they are primarily herbivorous and have narrower dietary requirements. Aquatic turtles are omnivorous, so they have a variety of sources from which to obtain their nourishment. But of course, they are not invulnerable, and can succumb to MBD if conditions are bad enough.

As mentioned above, pyramiding is primarily a problem of the underlying bones of the carapace. In chelonians with pyramiding, the bones of the shell are expanded, meaning they are not only taller (forming pyramids), but are also less dense than normal bone. Here are a couple of photos that do a good job of showing how malformed the bones of pyramided tortoises are.

*Source:* http://startortoises.net/pyramiding.html
*Healthy carapace:*





*Pyramided carapace:*





Notice how the bones in the pyramided carapace are not only lumpy, but also more porous.

The next question is, how does bone become so porous? Probably because it is not getting what it needs, namely the right amount of calcium, the right amount of vitamin D3 (to metabolize the calcium), and the proper rate of growth. These factors explain why omnivorous turtles don't get pyramiding nearly as often as herbivorous tortoises. Turtles get lots of calcium from the skeletons of their prey; tortoises must rely on calcium-rich vegetation and mineral licks. Turtles can also get vitamin D3 from their prey, as well as by exposure to sunshine; tortoises must rely almost exclusively on exposure to sunshine. Finally, turtles are adapted to fairly rapid growth due to their energy-rich food. In contrast, tortoises are adapted to slower growth, so if they get too many calories too often, their bones' growth rate can outstrip the supply of calcium in the body, leading to porous bone.

This is why feeding too much raw protein (like ground beef) can lead to pyramiding in tortoises, and more rarely in turtles, too. Not only is the additional protein providing too many calories and fueling accelerated growth, but it also prevents the animal from eating calcium-rich, vitamin D3-rich foods. Add to that the strain on the kidneys and the excess fat, and you are sure to get a sick chelonian.

It is interesting that experiments have demonstrated that elevated humidity can promote smooth shells in tortoises. Clearly, the humidity is doing something, too - perhaps promoting slow, even growth of the keratinous scutes. However, aquatic pond turtles and semi-terrestrial box turtles can also get pyramiding with a poor diet, so this seems to indicate that metabolic factors are at least as important as environmental factors, if not more so.


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## EricIvins (Jul 19, 2012)

GeoTerraTestudo said:


> One thing we know that pyramiding is _not_, is this:
> 
> 
> 
> ...



Using a Turtle that shed its scutes is a fairly bad example, as I have seen Turtles that looked like that shed the accumulated scute layers and look perfectly normal afterwards.......

Try to find an example of a pyramided Turtle that doesn't shed its scutes and take it from there........


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## GeoTerraTestudo (Jul 19, 2012)

EricIvins said:


> Using a Turtle that shed its scutes is a fairly bad example, as I have seen Turtles that looked like that shed the accumulated scute layers and look perfectly normal afterwards.......
> 
> Try to find an example of a pyramided Turtle that doesn't shed its scutes and take it from there........



No problem:

*Box turtle with MBD (tragic example):*




http://www.tortoisetrust.org/articles/webdiet.htm

*Red-eared slider with pyramiding:*




http://bamboozoo.weebly.com/the-turtles.html

I also have some pix of Florida red bellied cooters with pyramiding (not shedding scutes), but because it is from another forum, I cannot post it here, as that would be against Tortoise Forum Guidelines. Feel free to PM me if you want more information.


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## Yvonne G (Jul 20, 2012)

Hi Gaddy:

I think Eric was making the point that water turtles eventually shed their scutes. All of them do. 

However, you've gotten me to thinking. I've seen some pretty lumpy RES and they LIVE IN WATER! So the "spray them 'til they drip" theory to prevent pyramiding, kind of falls out the window when you think about that, doesn't it.


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## Tom (Jul 20, 2012)

Two very different phenomenon happening between water turtles and tortoises. Not even apples to oranges. More like trees to mushrooms...


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## EricIvins (Jul 20, 2012)

emysemys said:


> Hi Gaddy:
> 
> I think Eric was making the point that water turtles eventually shed their scutes. All of them do.
> 
> However, you've gotten me to thinking. I've seen some pretty lumpy RES and they LIVE IN WATER! So the "spray them 'til they drip" theory to prevent pyramiding, kind of falls out the window when you think about that, doesn't it.



Actually, all Turtles do not shed their scutes - Alot of North American species do, but some don't.........

The point was that most North American Sliders that have shell issues have nothing to do with "pyramiding"........In fact, all it takes is 6 months of wheat germ Koi pellets, and those "lumpy" Sliders turn into smooth animals.......That has nothing to do with MBD.......


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## GeoTerraTestudo (Jul 20, 2012)

Tom said:


> Two very different phenomenon happening between water turtles and tortoises. Not even apples to oranges. More like trees to mushrooms...



I disagree. Sure, pond turtles can shed their scutes, but pyramiding is a deformation of the underlying bone. So, even though they shed their scutes from time to time, if the carapace has lumps, they will remain.

Terrapins and tortoises do have different diets (omnivorous vs. herbivorous), but in both cases, the animal is not getting the nutrition it needs in the right amounts (calcium, vitamin D3, and calories), so the result is deformity in the bones of the carapace.

The phenomenon is not limited to chelonians. As mentioned above, we're basically talking about rickets, which can happen in any vertebrate, including us.



EricIvins said:


> Actually, all Turtles do not shed their scutes - Alot of North American species do, but some don't.........
> 
> The point was that most North American Sliders that have shell issues have nothing to do with "pyramiding"........In fact, all it takes is 6 months of wheat germ Koi pellets, and those "lumpy" Sliders turn into smooth animals.......That has nothing to do with MBD.......



The slider in that first picture may be shedding its scutes, but the one in the second picture has a more profound issue of bone deformity, which scute-shedding will not remedy.


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## CLMoss (Jul 20, 2012)

OK, here is my question: Is pyramiding in the case of "Star tortoise" more or less cosmetic? Also, is there a chance that heredity (natural selection) plays a larger role than has been discussed? In the past I raised three young Stars (I don't know if they were SL Stars or mainland Stars, they were wc). Each shared the same environment; food, humitity, vitimans, etc., And each shell developed differently: two had moderate pyramiding and one was very smooth. 
I am aware that I am speaking about a smaller gene pool than other tortoise species located around the world; however, I believe that there is something to be learned in comparing these different species. All of the adult (15-20+ year old) Stars that I have met, including my hatchling's mother, and photos that I have seen of Stars have had tent-like scutes (pyramiding).
Please note that all of this scientific information is new to me, and I am just trying to understand how to care for my hatchlings. Also, I am a bit surprised how few Star owners there are on this forum and/or that are interested in this topic.


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## mctlong (Jul 20, 2012)

GeoTerraTestudo said:


> *Source:* http://startortoises.net/pyramiding.html
> *Healthy carapace:*
> 
> 
> ...



This is a fascinating picture, thank you for posting. I work with human skeletal remains. Our bones thicken in areas that are psysically stressed. This is the body's way of creating a natural armour to prevent the bone from wearing away, breaking, or from sustaining additional injury. For example, if I were to break my arm, the bone around the break would heal (assuming I'm a healthy person with suffiient calcium reserves). In addition, the healed bone (scar) will be thicker than surrounding bone. This is the body's way of protecting high-impact areas. Another example, if I were a professional baseball pitcher, the segment of bone in my arms that are attached to the well-worked pitching muscles would be thicker than surrounding bone. Why? - because the stress of the enlarged muscles triggers the body to thicken the bone. This thickening allows the bone to bear the weight and stress of the muscles. 

Am I making sense?

Okay, so mammels and reptiles are very different creatures. However, when I look at these pictures, the first thing I think is that the bone directly under the scutes is physcially stressed. The body is cushioning the bone the protect it. 

If this is the case, my question is - What is causing the stress? 

Some possibilities:

1.) Heat stress - The scutes are getting too hot. This heat damages underlying bone. Bones reacts/heals itself by thickening. This protects the bone, and as an added benefit, helps regulate the tort's core temperature in its hot habitat. 

2.) Cold Stress - The scutes are getting too cold. This cold damages underlying bone. Bones reacts/heals itself by thickening. This protects the bone, and as an added benefit, helps regulate the tort's core temperature in its frigid habitat. 

3.) Impact - Something is impacting (hitting, rubbing against, etc.) the scute, damaging the underlying bone. This impact causes tiny fractures in the bone. The bone reacts by thickening to prevent further damage.

4.) Pressure - Something is applying pressure to the scure above the bone. This pressure could be something as minor as air pressure. Some other things that may cause pressure include the weight of soils in burrows, the weight of a flipped tortoise on its back, or the weight of a heavier-than-average scute.

5.) Scute elasticity - Something is preventing the scutes from expanding and growing property. This lack of elasticity creates tension in the areas of the bone attached to the scutes. The bone thickens to handle the stress. This could be particularly damaging if the bone is growing at a different rate than the scute.

Anyhoo, this is just me thinking outloud. 


Geoterra also makes an excellent point when he points out the porosity of the bone which could very well be a lack of calcium. 

Thicker bones require more calcium. I would not be surprised to see a calcium deficiency in an animal with thicker than average bones. This is because the body will require more than average calcium to sustain the thicker than average bones.


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## GeoTerraTestudo (Jul 20, 2012)

Shelly, you raise a good point about bone thickening in response to stress. However, as you said, stressed bone is _more_ dense, not less. The bones in that X-ray are porous, indicating a lack of calcium apatite, and not an abundance of it. This comes about from metabolic disease.

As I mentioned above, although the causes of pyramiding are debatable, they do seem to fall into two camps: metabolism and hydration. Both are probably at play, though. Pyramiding usually occurs in young tortoises, who have more rapidly growing carapaces. Not only are they more vulnerable to metabolic disease, but if their carapace is dry, then the keratin in their scutes may warp, causing the thin, underlying bone to bow outward. So, both nutrients and humidity may lead to pyramiding in herbivorous, terrestrial tortoises; for omnivorous, aquatic turtles, it's probably just nutrients.

As for Indian and Burmese star tortoises, and _Psammobates_ tortoises, some degree of pyramiding appears to be natural. As their names suggest, these species have star-like patterns on their scutes, so having raised scutes may improve their camouflage.

Redfoot and leopard tortoises, like most species, tend to grow smooth carapaces. However, in they wild, they may exhibit some mild pyramiding.

*Wild leopard tortoise (location unknown):*




*Source:* http://www.livingdesert.org/desert_animals_new_sub_animal.html?id=60

*Wild redfoot tortoise in Venezuela:*




*Source:* Photograph taken by me

I don't know why these two species exhibit minor pyramiding in some parts of their range, but not others. Both species are found in both forest and savanna habitats, so maybe they don't have pyramiding in more humid areas, but do exhibit pyramiding in the drier parts. Also, maybe they grow more quickly during the dry season in some areas. Finally, perhaps some individuals have been slightly malnourished for part of their lives.

Here are some good articles on pyramiding:
http://www.tortoisetrust.org/articles/pyramiding.html
http://www.petinfoclub.com/Exotics/Know_your_pet/Health__pyramiding_in_tortoises.aspx
http://www.reptilechannel.com/turtles-and-tortoises/tortoise-care/pyramiding-in-tortoises.aspx
http://redfoottortoise.com/redfoot_tortoise_pyramiding.htm
http://islandbiodiversity.com/Afr J Herpetol 2004 tortoise diet.pdf
http://africantortoise.com/_sulcatadiet2.pdf
http://onlinelibrary.wiley.com/doi/...sCustomisedMessage=&userIsAuthenticated=false


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## mctlong (Jul 20, 2012)

GeoTerraTestudo said:


> Shelly, you raise a good point about bone thickening in response to stress. However, as you said, stressed bone is _more_ dense, not less. The bones in that X-ray are porous, indicating a lack of calcium apatite, and not an abundance of it. This comes about from metabolic disease.



I said bones under stress become thicker. They do not necessarily become more dense. 

Keep in mind that a thickened bone will need more calcium than a regular bone. If it does not get the additional calcium it needs to produce the additional bone mass, the bone will still thicken under stress, but will be porous. If there in insufficient calcium for the bone to heal properly, a physically stressed bone will become thicker _and _ will be porous. 






Following this same topic of calcium....

A deficiency in the absorption of calcium can cause bones to be more brittle and prone to breaking or getting fractures/microfractures when stress is applied. When this weak bone fractures, the thickened scar forms around it. This process of healing/thickening depletes the body of calcium even further (calcium is used to build new bone material around the injury). This weakens the bones even further because the body has less calcium. 

Theoretically, this could become a dangerous cycle where the bones become more and more brittle and break more often leaving an animal deformed with brittle, soft, porous bones that are deformed with porous lumps (thickened areas). Ouch!


I guess you could compare it to some of the deformity you see in rickets.


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## Tortus (Nov 18, 2012)

Interesting topic.


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## Tom (Nov 18, 2012)

Here is something to consider in all of this: If any of the pyramided specimens that we are discussing had been raised in a closed chamber with the correct temps and humidity, with all other factors (diet, calcium, etc...) remaining the same, do you think they would still have pyramided? I don't.


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## lovelyrosepetal (Nov 18, 2012)

I don't think they would either. Going back over many old posts and seeing how so many sulcatas have been raised smooth with high humidity and lots of soaks, since that time and then seeing how pyramided they are when they were raised dry, leads me to believe that hydration is the key factor to some of these species pyramiding or not. I have some sulcatas that were started with good hydration and I have kept it that way and they are looking smooth and healthy. I have seen Tom's sulcatas that he has raised and they are the smoothest, most perfect sulcatas and he keeps them very hydrated and humid. I have also seen many sulcatas that, from the beginning, were kept dry and they have pyramided. If it is mainly diet you would see a lot smoother and healthier sulcatas, but most people don't keep them hydrated and then you get the pyramiding. I am only talking about sulcatas, I have no experience with any other species. I don't even think that after all the examples that this is opinion, it seems to me to be fact. If it looks like a duck, if it quacks like a duck......


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## Kapidolo Farms (Nov 18, 2012)

Associated things to consider.

1) We expect a much higher 'success' rate for captives than wild, each animal is not a genetic duplicate, so there may be a genetic component, that would tend to remove readily pyramiding individuals out of wild populations. Not that Pyramiding itself is maladaptive, but could be associated with some other maladaptive trait. I do not know this or have any evidence to suggest it is true, it's am idea to consider.

2) At least for eggs, different forms of calcium make different calcium crystals in egg shells. Perhaps the form the calcium as consumed has some effect on how the bones in the shell are formed. I do not know this or have any evidence to suggest it is true, it's an idea to consider.

3) Indian stars and the Tents are considered to be 'natural' pyramiders. However I have seen tents in the wild both pyramided and not. I have seen Indian stars both pyramided and not but all captives for live animals. I have seen preserved Indian Stars from Pakistan, that were as smooth and big and round as sub-adult radiata. 

4) Wild tortoises become as fixated on diet items as captives. There are enough studies to suggest this as a general principle. The more restricted the choices in the wild over all and for any one season/year the strong the selectivity signal (aberrant shell growth) may be.

5) Gut flora in tortoises is much more fooled with by keepers than would be the case in wild tortoises, which without regard to food offered, impacts what nutrients are readily available in one form or another.

6) Many nutrients come in a wide range of forms, and most testing is not precise enough to differentiate those forms. The tests used are geared towards human diet and nutrition.

These are further considerations to confuse the issue. I'll not suggest I have an answer.

Will


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## sibi (Nov 18, 2012)

I would tend to agree with Mark. Based on my experience with raising sulcatas, dry environments that are artificially induced produce all kinds of problems for the tort, in addition to pyramiding. Sulcatas are not designed to thrive in hot, arid climates despite their origins. In the wild, they would know how to stay out of the heat, burrow to keep warm, eat as they go on their merry way. No doubt, if left to themselves, they would thrive and look beautiful (barring any drought or food shortages). Proper diet as described above with enriched calcium levels, exercise, exposure to sun which will help the calcium to be absorbed, HUMIDITY levels adequate enough to help shape scutes and help prevent pyramiding are some of the essential conditions for sulcatas. Now, as someone mentioned before, there may be some torts that don't need so much care as captives, but sulcatas aren't one of them. Tom has for years grown and observed the ideal conditions for raising sulcatas in captivity, and I for one agree with his assessment on sulcatas. These magnificent creatures know how to keep themselves fit in the wild--they were designed that way. But, having them in captivity now puts each one of us as their steward. We have to be mother nature to them, and I'm mighty glad to have some of the best experts on raising sulcatas here on this forum to learn from their mistakes so that we don't have to make them ourselves.


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## tortoises101 (Nov 19, 2012)

A hypotheses on MBD and pyramiding in aquatic turtles is that it is largely a result of a diet too high in fat and protein. When food high in macronutrients such as fat and protein (hamburger, for example) are offered, it puts a great deal of strain on the liver and the liver cells begin to detriorate, thus reducing the liver's ability to absorb calcium and D3. During this process, the shell will grow much slower or develop a collapsed structure, regardless of how much calcium or D3 is included in the diet, causing MBD. The improper growth of the shell will induce the scutes to not shed and begin to stack, resulting in a pyramided structure.


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## Tortus (Nov 19, 2012)

That's fascinating. So pyramiding in aquatic turtles and tortoises is not related at all? 

I'm surprised this thread stayed buried for so long. The scientific community could learn a lot by coming here.


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## tortoises101 (Nov 19, 2012)

Tortus said:


> That's fascinating. So pyramiding in aquatic turtles and tortoises is not related at all?
> 
> I'm surprised this thread stayed buried for so long. The scientific community could learn a lot by coming here.



They have a different shell structure and live in very different environments; two fundamental factors. 

I agree 110%.


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## Baoh (Nov 19, 2012)

Tortus said:


> The scientific community could learn a lot by coming here.



Hilarious.


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## Tom (Nov 19, 2012)

Will, I love the way you have presented the info in your last post. All of those things ARE worthy of some consideration. I do not have your knowledge or experience with wild torts and I appreciate you sharing this insight with us. [end of comments specifically to Will.]

To all, Here are some things that I have shared in the past, but bear repeating in light of this current discussion.
1. My current adults, and all the previous ones too, (sulcatas AND leopards) were all raised dry, as was recommended by all the books, breeders and "experts" of the day, back in the 90's. They all pyramided. We are talking about a dozen animals and their pyramiding was suprisingly consistent over about a ten year period. Knowing what I know now, the consitency of their pyramiding is not a surprise. I tired various housing and feeding regimes, but all were housed dry, since that is what was assumed that sulcatas (and leopards) needed back then. Their direct offspring were raised humid and hydrated. Damp substrates, covered tops, daily soaks and shell spraying. Even though these are the direct offspring of moderately pyramided adults, they are smooth. Their diets, temps and enclosures were all very similar. The one factor that was dramatically changed was the "wet" factor. This, along with many other similar observations all over the world, is why I believe that genetics only plays a minimal role, if any.

2. Diet. I know a man in south Florida who proudly showed me pics of his super smooth large sulcatas. He raised them entirely outdoors in his back yard. He found it amusing that they had learned to climb up onto the low back porch and eat all the cat food out of the bowl. They had been doing this daily for nearly their whole lives. They also ate whatever weeds and grass grew in their back yard, but he really didn't feed them. They were approximately 80 pounds at 5-6 years old. If you didn't know better, you would swear they were wild caught and at least 10 years old. Again, I have observed similar dietary atrocities with the results dependent upon the environment in which the tortoise were raised. Feed them cat food in Southern CA or AZ, and you get a horribly malformed, pyramided mess. Feed them cat food in the south Florida or Louisiana rain, warmth and humidity, and you get large, but smooth tortoises. Mind you, I am NOT advocating what is clearly a bad diet, I am just pointing out that even on a diet that any reasonable tortoises keeper would assess as "bad" the tortoises still grew smooth and looked like their wild counterparts.

On the other side of this same coin, I raised my current adults on an excellent diet and fed small quantities, even skipping days occasionally, based on the advice of the day which was that, "too much nutrition, is just as bad as the wrong nutrition". My current adults ate mostly grasses and weeds, almost no grocery store greens, a fair amount of cactus, all in reasonable small quantities. They were always hungry, but I was attempting to simulate what I was told happens in the wild. Of course I kept them dry, since I was told they were a "desert" species that came from dry arid regions just South of the Sahara desert. They grew very slowly. They are now 14.5 years old and just barely 70 pounds for my two males, and 40 pounds for my female who is one year younger. Most of that growth is in the last three years, since I started feeding the, a more reasonable diet. I have produced "mini" sulcatas, if you will, for all my efforts. As anyone can see from the pics I have posted, they are quite pyramided. As Will pointed out, this COULD have something to do with the nutrient content of the food I fed them. My question then is: Why are their offspring, who were started in the same exact enclosures, on the same ranch, fed the same foods that grew in the same weed patches, drank the same water, NOT pyramided? The only variable that changed from 1998 when the great Walter Allen gave me Scooter and Bert, to 2010 when I finally bred Scooter and Bert, is the water management strategies that I have employed with their offspring.

I don't have documented lab studies to prove what I assert. I only my have short lifetime of personal experiences and observations. There IS the Austrian study of 2003 the DID prove that protein does NOT cause pyramiding, and that humidity DOES prevent it...


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## Kapidolo Farms (Nov 19, 2012)

Tom said:


> There IS the Austrian study of 2003 the DID prove that protein does NOT cause pyramiding, and that humidity DOES prevent it...



Tom, is this something handy where you could offer a more specific reference for. Even the primary author would help. Thanks.

Will


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## Tom (Nov 19, 2012)

I tried to look it up and post it for you, but the link is no longer there. I apologize. I have a very weak 3G wireless signal here, so it might just be that is is not popping up for me. It was on the sulcatastation.org website. There is now only a summary of the results, but the summary is followed by the correct citations. I tried to link it here for you, but my weak signal is not cooperating. You'll have to go to the ss website, click on the highlighted link that says "What causes pyramiding.", and the summary is a few scrolls down the page.


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## Neal (Nov 19, 2012)

http://africantortoise.com/_sulcatadiet2.pdf

_Influence of environmental humidity and dietary protein on pyramidal growth of carapaces in African spurred tortoises (Geochelone sulcata)_


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## Tom (Nov 19, 2012)

Thank you Neal.

Will, given your background, I would love to hear your thoughts on this study. It seems valid to my untrained (scientifically speaking) eye, but Andy Highfield called it "flawed" and referred to the humidity thing as "a red herring", at one point.


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## Kapidolo Farms (Nov 19, 2012)

Tom said:


> I tried to look it up and post it for you, but the link is no longer there. I apologize. I have a very weak 3G wireless signal here, so it might just be that is is not popping up for me. It was on the sulcatastation.org website. There is now only a summary of the results, but the summary is followed by the correct citations. I tried to link it here for you, but my weak signal is not cooperating. You'll have to go to the ss website, click on the highlighted link that says "What causes pyramiding.", and the summary is a few scrolls down the page.



Got it . . .

Wiesner CS, Iben C. 2003.
Influence of environmental humidity and dietary protein on pyramidal growth of carapaces in African spurred tortoises (Geochelone sulcata).
J Anim Physiol a Anim. Nutr 87:66-74.

and now so does everyone else.

View attachment Wiesner - 2003.pdf



Will


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## evlinLoutries (Nov 20, 2012)

Tom said:


> The answer to number one is a big "maybe". Depends on species, age, sex, diet, etc...
> 
> The answer to number two is a definitive "no". Whether a tortoise gets a calcium supplement every day, or never at all, will have no effect on whether or not it pyramids.
> 
> ...



I agree with Tom, its the humidity and its food that cause the pyramid..

Too much proteint I think can cause pyramid too, such as beans, or even dog food or cat food..

For my experience, good diet, with correct food and great enclosure(place) with humidity more than 60-70% can make tort growth smoothly..


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