# Do not rotate the eggs



## fzb2099

We always here this in breeding sheets:

"Do not rotate the eggs vertically, it could kill the embryo".

I've been searching for a while and I cant find anything to for the basis of this advise. (other than the fact the reptile eggs have no chalazae)

Anyone know where this comes from? and are there recorded event than flipping the egg vertically would definitely kill the embryo?

Thanks.

ps. and yes, u guessed it. I have 3 eggs which were outside the snake coil and I just want to make sure I give them the best chance possible when I incubate them. The MUST have rolled away from the clump, so I need to know which way is up.


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## paulh

I know that chicken eggs must be turned a couple of times a day to develop properly. Reptile eggs, on the other hand, are usually laid and left in their original orientation. But I am not aware of any experimentation to see just how much a snake egg can be turned without damage and at what age an egg is most resistant to damage from turning. My gut feeling is that laying time is when they have to be most resistant.

I can tell you that once I accidentally dropped a snake egg three feet, and it went bouncing across the floor about 10 feet to the wall. That embryo did not survive. But in those circumstances a chicken egg shell would have just broken. So I don't call it a fair test. 

And another time I was given some two day old snake eggs, and they sat on the floor of my car as I drove 40 miles to get home. Most of those eggs did not survive, but a couple hatched normally. On the other hand, the eggs were badly dehydrated when I got them, so I have no way of telling which eggs died of dehydration and which died of excessive movement.

For what it's worth, I'd just keep those three eggs in their present orientation.


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## ian14

Bird and reptile eggs are totally different. In bird eggs, the embryo is not attached to the shell - you will have seen from using a chicken egg that the yolk is loose and surrounded by the egg white. The yolk is the embryo, whichm if the egg had been fertilised, would eventually develop into the chick, with the albumen providing all the nutrients. The shell is also hard and so water loss/retention and oxygen transfer is not an issue. However, in reptile eggs, the embryo becomes attached to the side of the egg shortly after being laid. If the egg is turned, the embryo can become detached from the shell and die.
This is why bird incubators cannot be used for reptile eggs, as most of them have an automatic turning mechanism so that the egg is turned regularly. If this happened with reptile eggs they would all die.


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## Marinam2

You can incubate reptile eggs in any orientation quite a few of my corn eggs have been presented vertically stuck on to others in a mass.

Its just important not to turn them or move them from that presentation once incubation starts. 

I believe it is possible to adjust presentation on a fresh egg so long as it isnt shuddered too much so the rolling would not be an issue if the egg was a few mins from laying but as i said once incubation starts and the egg is settled it needs to be left alone.


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## Matt Harris

fzb2099 said:


> We always here this in breeding sheets:
> 
> "Do not rotate the eggs vertically, it could kill the embryo".
> 
> I've been searching for a while and I cant find anything to for the basis of this advise. (other than the fact the reptile eggs have no chalazae)
> 
> Anyone know where this comes from? and are there recorded event than flipping the egg vertically would definitely kill the embryo?
> 
> Thanks.
> 
> ps. and yes, u guessed it. I have 3 eggs which were outside the snake coil and I just want to make sure I give them the best chance possible when I incubate them. The MUST have rolled away from the clump, so I need to know which way is up.


In one sense it stands to reason that an egg has evolved to not being turned, then you shouldn't turn it, and reading about the structure of reptile eggs, I can see how turning could damage them, as Ian says above. However, I've never seen any research which provides evidence that turning eggs kills the embryo, and if so, why.

It seems to me that the advice not to turn reptile eggs is based on assumption rather than proof, although it's probably a correct assumption.

What is needed is someone to take a whole load of eggs and turn some of them to differing extents and at differing times during incubation, and compare hatching rates with a control sample.


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## ian14

Matt Harris said:


> In one sense it stands to reason that an egg has evolved to not being turned, then you shouldn't turn it, and reading about the structure of reptile eggs, I can see how turning could damage them, as Ian says above. However, I've never seen any research which provides evidence that turning eggs kills the embryo, and if so, why.
> 
> It seems to me that the advice not to turn reptile eggs is based on assumption rather than proof, although it's probably a correct assumption.
> 
> What is needed is someone to take a whole load of eggs and turn some of them to differing extents and at differing times during incubation, and compare hatching rates with a control sample.


I am pretty sure that it has nothing to do with an assumption, but due to the physiology of the egg - by being turned the embryo becomes detached from the shell. The shell is porous to allow gas and water vapour transfer, with blood vessels attached to the shell itself. When I get 5 minutes I'll have a look in one of my old uni textbooks, I am sure it was in there. To clarify, turning vertically has nothing to do with it, turning full stop can cause the embryo to detach.


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## fzb2099

The only thing I'd dispute with the comment above is:

The embryo in a reptile egg sits on the underneath the top surface of the egg. Hence, it is wrong to say that flipping the egg with detach the embryo (which will then be at the bottom)

Most people say that flipping it causes the embryo to sit at the bottom and then is "drowned" in its yolk. Is there any evidence of this?

And if the drowning is true, then there must be a maximum degree of rotation before it drowns. picture this, embryo is on top, u turn the egg 10 degree, it's still relatively top. U turn it 90 degree, the egg is on a side wall.. will it drown? a full 180 degrees and its definitely in the bottom.

Firstly, I dont really believe the drowning theory. Its unproven and to simplistic. Surely evolution has accounted for snake eggs to be subject to some movement. Imagine is a female's nest is attacked by predators. In her defense of the eggs, moving her body and distending the coil, at least one eggs would wobble.

opinions anyone?

ps. Its healthy that we are discussing this. Too many care tips have no scientific basis. I hope someone with the means picks up on this and tries to prove the theory, one way or the other.


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## pigglywiggly

ian14 said:


> Bird and reptile eggs are totally different. In bird eggs, the embryo is not attached to the shell - you will have seen from using a chicken egg that the yolk is loose and surrounded by the egg white. The yolk is the embryo, the yolk is the food for the embryo whichm if the egg had been fertilised, would eventually develop into the chick, with the albumen providing all the nutrients. The shell is also hard and so water loss/retention and oxygen transfer is not an issue.if this were true the chick would suffocate long before it hatched! However, in reptile eggs, the embryo becomes attached to the side of the egg shortly after being laid. If the egg is turned, the embryo can become detached from the shell and die.
> This is why bird incubators cannot be used for reptile eggs, hovabators are for birds as most of them have an automatic turning mechanism so that the egg is turned regularly. If this happened with reptile eggs they would all die.


 :whistling2:


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## Matt Harris

ian14 said:


> I am pretty sure that it has nothing to do with an assumption, but due to the physiology of the egg - by being turned the embryo becomes detached from the shell. The shell is porous to allow gas and water vapour transfer, with blood vessels attached to the shell itself. When I get 5 minutes I'll have a look in one of my old uni textbooks, I am sure it was in there. To clarify, turning vertically has nothing to do with it, turning full stop can cause the embryo to detach.


That sounds fine in theory, as does the 'drowning in yolk' theory, but is there any evidence to prove an effect?


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## Nix

I am with Ian on this one. It is about detachment of blood vessels. Reptile eggs are polar. 

Eggs laid in any orientation can hatch as long as the orientation isn't changed after they are laid. If you have 3 separate from the others incubate them in the orientation they are currently in.


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## Matt Harris

Nix said:


> I am with Ian on this one. It is about detachment of blood vessels. Reptile eggs are polar.
> 
> Eggs laid in any orientation can hatch as long as the orientation isn't changed after they are laid. QUOTE]
> 
> Have you (or anyone else) tried changing orientation to find out? As above, it sounds fine in theory, but where's the proof?


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## LorriAnne

*Newbie here, but I searched for this...*

and came across some info that others interested in this topic might find helpful.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4543940/

If the link doesn't show up because I am new, search for 
Myth busting? Effects of embryo positioning and egg turning on hatching success in the water snake Natrix maura
Fabien Aubret,a,1 Gaëlle Blanvillain,1 and Philippe J. R. Kok2

It is an article from the US National Library of Medicine 
National Institutes of Health


I was interested in this because I live with my youngest son in Bolivia and we just found some snake eggs yesterday.We both love snakes - they are so cool! We have a baby Peni lizard right now that our cats caught, though, but no snakes. We rarely see them. The landlord cleared a bunch of grass away and now we see snake holes everywhere.


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## ian14

LorriAnne said:


> and came across some info that others interested in this topic might find helpful.
> 
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4543940/
> 
> If the link doesn't show up because I am new, search for
> Myth busting? Effects of embryo positioning and egg turning on hatching success in the water snake Natrix maura
> Fabien Aubret,a,1 Gaëlle Blanvillain,1 and Philippe J. R. Kok2
> 
> It is an article from the US National Library of Medicine
> National Institutes of Health
> 
> 
> I was interested in this because I live with my youngest son in Bolivia and we just found some snake eggs yesterday.We both love snakes - they are so cool! We have a baby Peni lizard right now that our cats caught, though, but no snakes. We rarely see them. The landlord cleared a bunch of grass away and now we see snake holes everywhere.


If you read the abstract of this paper, below, it would appear that science does confirm that snake eggs should not be turned.

Scientific Reports
Nature Publishing Group
Myth busting? Effects of embryo positioning and egg turning on hatching success in the water snake Natrix maura
Fabien Aubret, Gaëlle Blanvillain, and Philippe J. R. Kok

Additional article information

Abstract
It is a common belief that reptile eggs should not be turned after oviposition once the embryo has attached itself to the inner membrane of the shell as it might kill developing embryos. Here, we used 338 eggs from 32 clutches of the water snake Natrix maura to (1) thoroughly describe natural clutch arrangement, (2) experimentally assess the effects of natural embryo positioning and (3) egg turning on embryo metabolism, hatching success, and hatchling phenotype. Clutches contained, on average, 59% of embryos located at the top, 28% at the bottom, and 14% on a side of the egg. Larger females laid larger clutches with higher proportion of top located embryos. Top embryos displayed higher metabolic rates (heart rates), shorter incubation time, and produced lighter and shorter snakes than bottom embryos. Egg turning did not significantly influence egg development, hatching success or hatchling phenotypes. However, post-birth mortality was significantly higher in turned (37.5%) compared to unturned (4.5%) embryos, providing support to the common belief that eggs should not be moved from their natural position.


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## dcap

ian14 said:


> Bird and reptile eggs are totally different. In bird eggs, the embryo is not attached to the shell - you will have seen from using a chicken egg that the yolk is loose and surrounded by the egg white. The yolk is the embryo, whichm if the egg had been fertilised, would eventually develop into the chick, with the albumen providing all the nutrients. The shell is also hard and so water loss/retention and oxygen transfer is not an issue. However, in reptile eggs, the embryo becomes attached to the side of the egg *shortly after being laid*. If the egg is turned, the embryo can become detached from the shell and die.
> This is why bird incubators cannot be used for reptile eggs, as most of them have an automatic turning mechanism so that the egg is turned regularly. If this happened with reptile eggs they would all die.


I think the shortly after being laid is the key part. That is why you'll see people lift the main mass of eggs and pop in the incubator box and any 'roll-outs' marked with an R and kept in the orientation you found them in. 

Always thought the thinking being is roll-outs have either been kicked out as duff eggs by the mother or accidentally rolled away. Quite often the roll-out will make it to hatch, so worth saving if you are incubating them all.

Have a watch of one of Jay's Retic egg collecting videos on YouTube [prehistoric pets] and you'll see the care taken to keep them upright but they just take any roll-outs and keep them right way up (they don't mark their eggs).

I put a small mark on mine just in case I knock them at anytime (Trinket eggs and a nose) ... plus since so far my colubrids have hatched over a 3-4 day timescale and one hatchling has managed to knock all the other eggs over which I then corrected (everyone hatched), I was glad I'd marked them (no idea if I needed to but wasn't going to chance it).


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## loxocemus

someone posted (as in mailed) a clutch of corn eggs from one uk keeper to another as an experiment. the clutch hatched fine.

rgds
ed

ps don't mail eggs, its just an interesting factoid.


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