Stillborn Hatchlings - any real reason?

SXE-C · #1 (**permalink**) 22-09-2009, 02:10 PM

HI,
This year has been a bit of a mixed bag for me in terms of our breeding success, I`ve had a lot of eggs and a lot of healthy hatchlings.

BUT - I`ve also had, upto now, around 10 perfectly formed `apparently` healthy young leos that have gone full term and just not made it out of the egg for some reason. The incubation process is spot on - mixed temp (we use a converted fridge) that is constant 81 degree at the bottom, 85 in the middle and 88 at the top. Obv statted etc..with a pulse stat. The tubs get aerated once a week to allow fresh air and possible rehydration (never getting a drop of water on the eggs, I know the danger of this)- these tubs being cricket tubs selloptaped until the last holes, to allow slight airflow and keep the moistrure levels stable. As an incubating medium, we use perlite, with every single scrap of water squeezed out. I really don`t think it`s anything with the whole incubation process or the methods - we`ve done the same for years without any problem.

The thing that leads me to think the process is ok, is the high number of healthy hatchlings we`ve had - not losing a single fertile egg to sinking OR mould all year, so the hydration/moisture part is ok I think. Condensation in the tubs isn`t a problem either.

What`s puzzling me - as I`ve had no problem putting most still born hatchlings down to nature, or simply an unfortunate, isolated weak hatchling that didn`t make it out the egg - is that the stillborns have had different mothers, different fathers etc - so not from 1 particular male or female. They`ve also been from clutches that have been incubated at high and low temps, and there`s also been times where both eggs have died, and times when 1 egg out of a clutch has failed yet the other one hatched. Why would an egg go full term, make it completely all the way and die at the last second - and why would there be a pattern for it?

I also know that some of the eggs have been alive (seen them wriggling about through the glass) after the egg had sunk, AND even when there`s been a slit in the egg, yet I`ve gone back an hour later and the hatchling hasn`t made it out the egg and has died (no movement for hours). I always leave any sunken (prob dead) egg for at least 3 days too before cutting it open, and they`re always dead by that point (the ones that haven`t hatched within a few hours anyway).

Why are they going full term - fully developed - and then not making it? Surely, if there was a temp or humidity issue, then they wouldn`t get all the way to the end, and they`d show at least some degree of deformity if they did make it and there`d been fluctuations (even the ones that don`t make it aren`t deformed/ and don`t have tail kinks etc).

Any help would be massively appreciated, as I just can`t understand why an embryo/hatchling would develop very well for a set time (say 50 days), the eggs perfectly fine too and then just as it`s about to hatch, something goes wrong. Would love some serious ideas please. Thanks.

Big Red One · #2 (**permalink**) 22-09-2009, 05:57 PM

Interesting...
I'm having similar results - 19 eggs laid form two different mums. 4 gone off, 2 stillborn hatchlings (same as you described) and so far 7 healthy hatchlings and one with a bent tail who's now improving.
It's annoying me though as I can't pinpoint a reason for thee 'failures' !!!

sparky_bubble06@hotmail.c · #3 (**permalink**) 09-10-2009, 10:18 PM

we've had it with beardie eggs this yr too and we've done EXACTLY the same as we did last yr when we got 100% hatch rate (amazingly lol)

if anyone could put a finger on these wierd going ons, would be interesying to find out.

maybe it could be just weak babies, but then i've had smaller ones hatch out than the 2 still borns this yr. we also had 1 that managed to get out the egg and die within the 24hrs in incubator (to absorb yolk sack)

Gregg M · #4 (**permalink**) 09-10-2009, 10:49 PM

Everyone who has issues says that their incubation is spot on.... The fact is that if the embryos go full term and die in the egg, there is most likely something wrong with your incubation...

You could be adding too much or too little water to you incubation medium... With perlite, you are not supposed to just "squeez" water out of it... Perlite is not an absorbant material... In your incubation container, it acts more like drainage stones... This could be your problem right there...

Something is causing you hatchlings to stay in the egg to long or die before they hatch... It could be due to himidity, temperatures, or improper gas exchange...

Improper humidity and fluctuations in temp will not always cause embryos to die early on in development nor will it always cause visual deformations...

Sorry to say, but when you run into that amount of issues, you might want to take a step back and look more closely at your incubation method... These issues are almost always the direct result of human error... We have all made mistakes when it comes to incubation... We just need to learn from them in order to better our results...

Prem Morph · #5 (**permalink**) 10-10-2009, 09:49 AM

I would be pointing a finger at Co2 build up. If your incubation box has insufficient ventilation Co2 can build up in the box, Co2 is a heavy gas and in only slightly elevated levels can make the neonate sluggish causing them to drown full term. I tend to use cadbury boxes for incubation boxes and drill a series of 3mm holes in both ends of the box and a few in the lid. When I set the box up, to start with I add vermiculite(or any of your preferred mediums) that has been moistened to the correct level and then add eggs, finally I weigh the whole thing and write on the box the weight. I weigh all the boxes weekly to maintain the correct amount of water just adding water to the box in the corner if required. I also visually check the eggs opening the lid of the box and then replace in the incubator.
Using this method over the last 20 years or so I would say I have had a 99% hatch rate (basically if its fertile its hatched)

Yazyaz1 · #6 (**permalink**) 27-10-2009, 01:26 PM

could also be too much calcium in the egg?, im not sure, never breeded, but crooked tails, dont leos tails have calcium in them? please dont be mean lol, i only just got my first ever leo

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