DIE: Way to determine genetics vs. environment? (Warning: graphic photos)

[LauRuffian]

Geez, what a year. My last clutch was due to hatch last week. This was from my first time pairing of my ghost het amel, 50% het motley (bred by Susan Willis) female to my ghost stripe 66% het amel, dilute male (also from Susan Willis). She laid what I considered a massive first-year clutch of 25 eggs, but most were slugs. Only 11 appeared viable and of which, only 8 candled fertile. Over the weeks of incubation, I watched those die off one at a time until I was left with just 3 good eggs come day 55.

At day 72 I noticed changes that I hope suggested pipping in two of the eggs, but alas, it was due to the babies being DIE. Removing them, both snow/coral snow babies were horribly deformed. The first clearly died earlier in development and seemed fused at the center, with many of its organs appearing outside the body:

The second baby appears pretty close to full term, but is similarly (though not as severely) deformed in the center:

Obviously, I'm not holding out a lot of hope for that last egg. At least I proved the male is 100% het amel, but...yeeeeesh.

I'm trying to determine if the disaster is due to incubation or just a baaaaad genetic combination between my male and female. FWIW, I was already planning on breeding them to different snakes next year, but obviously if it's environmental I'd like to do what I can to prevent such a disaster--especially since the male might be bred to my son's beloved girl for her first season.

Details: Eggs were incubated in an Exo-Terra fridge-style incubator on the top shelf. I bought the incubator last year because it cools as well as heats--important in Southern California. It was set to 84 but actual temps on the shelf containing these eggs was about 81.7ish, with a couple of hot days bumping it to about 85 or so but never above that I observed. I did notice the egg box seemed to have a lot more moisture on the sides than I've seen with other clutches, but there wasn't much in the way of mold so I wasn't concerned. My other clutch in with this one had about the same hatch rate as the same pairing produced last year, with one DIE (that I'm pretty sure is due to the location of the egg--buried on the bottom of an egg-pyramid and the baby couldn't fully pip through) and one runt that died 24 hours after hatching. The remaining hatchlings are healthy (no deformities/kinks, etc.) and all ate at first asking.

Both of the snakes are registered with the American Corn Snake Registry and their pedigrees can be seen here:
Male, Theo
Female, Alina
While they are not siblings, there is some inbreeding; their fathers were full brothers a few years apart, for one. Still, this is not unusual in this hobby. Next year I intend to breed them both to completely unrelated snakes (Alina to an ultramel anery tessera, Theo to an amel het motley.)

So the essence of my question is: Is there a way to determine whether this disastrous clutch was due nature (catastrophic genetics) or nurture (incubation issues)?

 

[HerpsOfNM]

So the essence of my question is: Is there a way to determine whether this disastrous clutch was due nature (catastrophic genetics) or nurture (incubation issues)?

I had similar happen with cal kings back somewhere around 99-00, I forget exactly what year. What I do remember was that back then I was using a hovabator for egg incubation. I had 2, one for snake eggs and the other for my leopard geckos. I had the cal kings set to 84°F if I recall as I was naïve in thinking I could use it as an overflow 'bator for excess leopard gecko eggs.

Of the 20 something cal king eggs I had in there, I only had 1 hatch. Prior to that I watched sibling eggs either do DIE-premature or go DIE-full-term. I chalked this up to 2 possible issues: 1) humidity and 2) temperature.

Back then I lived in southern New Mexico - possibly quite similar to your difficult situation of maintaining both humidity and temps. I feel confident in ruling out humidity as I incubated in some Rubbermaid food storage containers with bed-a-beast (aka coconut fiber/coco coir/tropical soil/etc) and that remained moist throughout incubation. I also always had fresh water in a couple standing water bowls within the incubator. That left temps. I suspect that I possibly had spikes and/or did not have the incubator at the temp I thought I had. The reasoning....it did ultimately get leopard gecko eggs placed into it around the same time the cal king eggs went in. Leos are TSD, higher temps (86-90°F) = male and lower temps (80-82°F) = female. Incubate at 84-86 and you should get a mixed ratio. None of the eggs that hatched were female from that 'bator. At a mixed temp I can still pull all male, but sex is locked in for leos at 2 or 3 weeks if I'm remembering correctly.

In 2001 and 2002 (I specifically remember those seasons), again I had similar happen to corn and great plains rat eggs. I had almost exact results as yours and it was due to temp spikes during those seasons. I had eggs go term, but the neonates were DIE and kinked/malformed just as yours.

I'd wager to bet it might have been temperature related. Unfortunately, the only means to possibly ruling that out is repeating the pairing and shooting for a temp of 78-82°F.

Had I been able to source 1 gallon glass pickle jars locally I had plans of attempting to just incubate at my herp room temp which runs 75-82 (night-day). A number of once prominent herpers (both field herpers and captive breeders) had discussed this in length on a now defunct private field herping forum I was privileged to be on. I'm mentioned this before on here, but those individuals strongly felt, and had the data to back it, that we as a community that keep North American colubrids actually incubate our eggs too high. Many of those guys were not even using an incubator, but as I mentioned, used 1 gallon jars placed in a warm closet with incubation temps at 76-79. I want to say I recall those gents reporting not many DIE, most hatchlings on average emerged much more robust, and most took straight to f/t / eating in general without hesitation. These guys were working with milk snakes (Mexican milks, NM milks, and one other species I'm forgetting), gray-bands, and I think there were some hognose. There might have been a suboc clutch or 2, but these guys were very much keepers of SW US stuff.

EDIT...typing up what I've done to possibly fix at least my woes...

So as for what I've done:

Well, in 2002 I purchased my first green tree python from Garrick DeMeyer. The GTP bug hit me hard and by 2003 I had 8 GTPs, which wasn't easy to do then on college kid income while working for $8.50/hr at a natural history museum 20 hrs a week. Determined to breed GTPs, I didn't do so until 2006/2007, paired in Nov 2006, eggs hatching in May 2007. In my determination I wanted to strictly do maternal incubation.

My herp room held a constant 85-86, which was perfect for this, but little did I know that in the process of mom making her hive of eggs that she'd crushed an egg. She came off the hive 2 weeks before due date and I had no plan B up and running. I dug out my male hovabator that the previous year I had dialed at 86°F, gave it 24 hrs to cycle up, and moved the eggs into it. I had the same happen all over again with kinked, malformed babies, except I did manage to get 2 perfectly formed baby chondros. 1 baby died within a month, refusing to touch anything. The other died 6 months later, where it would tease feed, but wouldn't actually eat its pink.

Around this time, Damon Salceies - one of the gentleman I hinted at of above - was in the mix of getting his albino chondro project off the ground. He posted over to the Morelia Viridis Forum a How-to for a "Cooler-bator" or "Igloo-bator" incubator. Damon and I spoke a few times via email regarding his set up as he'd made some changes, but never posted about it to either the forum or his former page on ks.com (I'll abbreviate it Rich oke: ).

I made my version using a 100qt Igloo cooler. Damon had a baffle in his design, but later removed it - I forget why. The idea was it was to supply fresh air into the incubator. The workaround he suggested to me was simply picking up a quality aquarium air pump and run a line into the incubator. That line sits in a 4in deep stainless steel bowl, the same kind you'd see at various restaurants to aid in keeping food hot. The bowl holds water, which is heated from below, and another bowl with food sits atop it, thus keeping the food warmed (Panda Express does this if you've ever eaten there).

This does 1 of 2 things: 1) within the incubator is pipe tape wrapped around a PVC frame at the bottom of the cooler and these stainless steel bowls sit on top of it creating a heat sink of increased surface area to avoid temp spikes when opening the incubator and 2) a source of humidity. I run an air line with a ceramic bubbler stone on the end into the middle bowl. Another frame, the white wire shelving you can find at Lowes or HD, sits on top of the bowls and then I use 3 cambro clear plastic food boxes to house my eggs. The pipe tape has no built in thermostat (tough to find this kind) and is controlled by an old school HerpStat ND. I have it set to 81.5°F in proportional mode, where it rarely goes above using 20% power to keep the bator heated.

Though I've yet to hatch chondro eggs within this set up, I have had excellent success with a number of other species to include corns. I absolutely LOVE the setup as I can pretty much control it by 0.2°; something that is needed if/when I try my luck at chondros again as temps naturally vary during maternal incubation and many replicate this within their incubators.

So, I'd personally look into going the cooler-bator route. I've not been much a fan of the "mainstream" commercial herp product corps as you can usually do better making it yourself and for less sometimes. I've definitely not been impressed by the incubators they offer, more often than not reading of or hearing about incubation failures.

 

[Tavia]

Last year I had quite a few DIES in my corn clutches, one in particular. None of them had anything obviously wrong with them and were near full term. None appeared to be kinked. That year I tried incubating at lower temps to see if it made a difference in size and eating, which it did seem to do. The ones that did hatch were more robust than my previous clutch the year before, but the dams and sires were different in those two years. Still, I felt like the incubator might have been spiking, leading me to distrust it and I'd also heard of other, long time breeders, using the shelf method and I've already been successfully incubating my Asian ratsnake and Crested/Gargoyle gecko eggs on a shelf in the reptile room that is kept around 74 to 77 degrees ambient, though the shelf usually stays a bit warmer and doesn't fluctuate much, generally around 76-79 degrees.

So this year I decided to incubate everything on the shelf. One clutch completely crashed, one half did, with many DIEs, fought mold and phorid flies and maggots through the whole thing, the first time I've ever had a problem with flies and the babies were very small and not very robust. That was a repeat pairing from my first year breeding that had smaller babies, so could have partly been genetic but I think these were even less robust than the first year's babies.

The final corn clutch were nice and big, robust babies, for the most part but one was kinked and one was a late term two faced DIE baby, though I'd guess that last's also more likely random genetic chance and or uncontrollable factors when the embryo started to form, not likely to be related to temps or humidity.

It sounds like a great lot of bad luck is going around with corns this year though, among many widely separated breeders, both experienced and otherwise, feeding from many different food sources, so I'm not sure it's all something the breeders are or are not doing or the genetic faults of the snakes or anything else obvious, though it might be something very subtle, I guess.

 

[HerpsOfNM]

It sounds like a great lot of bad luck is going around with corns this year though, among many widely separated breeders, both experienced and otherwise, feeding from many different food sources, so I'm not sure it's all something the breeders are or are not doing or the genetic faults of the snakes or anything else obvious, though it might be something very subtle, I guess.

I've been hearing the same from many off-line sources, that this season's just been crap shoot for a number of people.

Something that's assumed nice within snake keeping is not really having to constantly gutload your feeders! It make sense, and yet it's absolutely astounding how nutrition is passed on from feeder insect to lizard and the consequences that occur on the offspring side if mom isn't getting proper nutrition. With snakes, again you can assume that by feeding a whole-food prey item you pretty much cover the nutritional needs to the breeding pair. The only real variable is whether one is feeding their snakes enough or not for mom to carry the burden of egg production, whether livebearer or egg-layer.

FWIW, I always did my cresties on a shelf. That's dating back to '98/'99. Only had one DIE back then until I got out of cresties in 2002.

 

[MysticExotics]

I agree. I used an incubator the first year, but have shelf incubated ever since. I've mostly had pretty good success, but this year wasn't as good.

 

[hypnoctopus]

I've only bred two clutches, but my first clutch was room temp incubated, and had 100% perfect babies - robust, healthy, good eaters. The temperatures for that clutch had some fluctuation because I was in the middle of moving, so they had to be in the car with me, and then on top of that, we had no air conditioning for a short period of time, so I was worried that that might have affected them, but thankfully it didn't.

My second clutch, this year, was also room temp incubated, and I had one DIE baby. It obviously died pretty early on in development; the color hadn't even come in yet and its little skull wasn't fused all the way shut. The middle of its body was all fused together and kinked like yours, but its organs were inside. This clutch has three non-feeders so far, and several of the babies are quite tiny, like 3-4 grams. However, the temperature this time was extremely stable, so I think it must just be a fluke.

Here's my little DIE baby:

I'm sorry you've had so much trouble with your babies!

 

[jet_set_willy]

Do all of you brumate your breeding pairs ?

I've read somewhere that some don't and was just wondering if this effected success rates at all?

 

[LauRuffian]

Thanks so much for your input and experience, everyone. Before I get into it, wanted to update that Baby #3, as I expected, didn't make it. Removing the dead baby (a ghost) revealed it was rather badly kinked and, like its siblings, had several organs outside its body. Eeeeesh. Pics:

Regarding possible incubator issues: A couple of times, I swapped this clutch with another one (the one that hatched healthy babies) so that they each spent time on the top and bottom shelves for several days. Granted, this one spent more time on the top than bottom, but thought that was worth noting. Also FWIW, the DIE in the other clutch were perfect looking (no kinks or deformities).

I kept thermometers on every shelf of the incubator and monitored temps very closely and it was always a hair under 82 (81.7 or so), with 1-2 days when it was crazy hot outside the temps reaching 85-86 or so for at most a half day. Still, HerpsofNM your words resonate so I'm trying to think if it's possible there were other, unobserved spikes. I can't dismiss it outright, but it seems unlikely. How much of a spike is enough to cause damage?

This was my first year using the Exo-Terra. In the past I've used a Hovabator, and my Miami girl produced robust (BIG babies!), healthy clutches with a 95% hatch rate at 82-84 degrees two years running. The following year, my lavender's clutch had poor eggs/hatching ratio, and there were issues of humidity and the like. Still managed 10 babies from 18 eggs, but I was concerned about the humidity issue and the possibility of heat spikes since the incubator can't cool. That's what led me to buy the Exo-Terra. If I recall correctly, Nanci LeVake uses the same type for similar reasons--she lives in a hot climate and wanted cooling capabilities.

My concern with shelf/closet incubation is temperatures can vary so much in the house, particularly since many exterior walls aren't insulated. Still, definitely worth considering. Right now I'm leaning toward going back to a Hovabator and maybe putting the incubator(s) in a different room.

jet_set_willy, no, I did not brumate my breeding pairs as in the past it's never been an issue. That said, this year I absolutely will at least to some extent. Around November or so, I'll stop feeding then turn off all heat sources a couple weeks after the last feed, darken the room, and outside of water ignore the snakes. I'll start warming them up and increasing light in January-ish. I also had rather lousy fertility rates, so I figure that can't hurt to try and do something to improve those.

From what I could see in the DIEs, the male is in fact 100% het amel, but wasn't able to prove if the female is het motley. At least I learned what I needed so it makes sense to continue with my plans to breed the male to my son's amel het motley female and then the ghost female to the ultramel anery tessera. I just need to come up with an incubation plan.

 

[Tavia]

This year was the first year that I brumated my corns, so I don't know if that had any effect or not.

 

[HerpsOfNM]

Do all of you brumate your breeding pairs ?

I've read somewhere that some don't and was just wondering if this effected success rates at all?

I've always cooled my colubrids, 1) to give me a break on feeding and cleaning and 2) numerous breeders have talked about infertility issues when they don't cool or when winters are warm enough (this is a southern US thing) that cooling doesn't really get to happen. I almost had the too warm a winter thing this season. I'll leave it at almost as jury is still out when it comes to actual hatching - stuff's still cook'n.

That said, usually not cooling results in infertility, thus you get eggs, but either slugs or infertile ova. All my females from 2014 had 2015 off due to not knowing if I was going to be renewing rental lease, thus either renting elsewhere and moving or buying a house. Unfortunately for me, my lease was set to expire in June, which years past was when eggs were hatching and/or still cooking. I didn't want that headache/heartache. Similar happened this year, except again all my females had last year off so everyone should have been recovered. My wife and I closed on our first home back in March, moved the herps down in April, and moved the rest of the house at the beginning of May. I didn't pair stuff until April, which is why I won't have eggs hatching until end of this month and all the way into Oct. AAAAANNNND it looks like a number of females are about to double clutch. :awcrap: :crying: :crazy01: :toiletgra

Tangent aside...I had 1 female, that dropped in 2014, give me nothing but 9 infertile eggs this season. Another proven (2013 & 2014) female also gave me 9 eggs of which 1 was infertile. A 3rd female gave me 11 eggs, of which 6 were infertile. 3 variables are at play here for me: 1) the males paired to these females were virgin, 2) only 1 female was virgin and she's the one that did 11 total with only 5 fertile, and 3) we had a warm winter here in north Texas. Even with this, I'm at 64 fertile eggs currently, with 2 females possibly still set to drop their first clutches for the year, and what looks to be possibly 3 females looking to double clutch.

Thanks so much for your input and experience, everyone. Before I get into it, wanted to update that Baby #3, as I expected, didn't make it. Removing the dead baby (a ghost) revealed it was rather badly kinked and, like its siblings, had several organs outside its body. Eeeeesh.

That's unfortunate. What's odd here is in say leopard geckos, eyelid and pigmentation development was some of the last traits to develop. If I recall, pigment is also one of the last things to develop in snake eggs. It's VERY curious that all you've posted, even the snows, show clear pattern and pigment migration development. So the question becomes why the delay in organs being inside the body? This could very well be temp/humidity related, it could be genetics, or it could be factors of both. :shrugs:

 

[LauRuffian]

That's unfortunate. What's odd here is in say leopard geckos, eyelid and pigmentation development was some of the last traits to develop. If I recall, pigment is also one of the last things to develop in snake eggs. It's VERY curious that all you've posted, even the snows, show clear pattern and pigment migration development. So the question becomes why the delay in organs being inside the body? This could very well be temp/humidity related, it could be genetics, or it could be factors of both. :shrugs:

I agree--if the babies were all just badly kinked, I'd more likely assume it was due to temperature spikes. But I find it quite peculiar that they got so far in development (near-hatching size, in at least two cases) without abdominal closure. I don't know muh about the stages of embryonic development, but as you suggested, from what I've read color is one of the last things to develop.

I'm not sure what effects humidity has on development, but now I'm quite curious. Last year I had an issue with insufficient initial humidity. A family emergency had me leaving the house 24 hours after they were laid and so I couldn't monitor initial conditions, and when I returned 4 days later they had started to dry and dent. Despite my efforts, the dented-due-to-drying eggs never recovered. That's why I wanted something with better humidity regulation. Perhaps, though, I overdid it and these eggs were too humid? I've only heard of humidity affecting eggs in either drying them out or causing mold, so I'm wondering what effect it may have on development.

Going to go do some more reading in the Corn Snake Genetics digital guide now...

 

[HerpsOfNM]

I know you can drown eggs with too high of humidity. And from what I've been told that's usually from trying to recover low humidity conditions. What I was told was basically to drape either paper towel or newspaper over the eggs and mist it to raise humidity back up. This leads to direct water contact to the egg surface, which in turn can lead to drowning I suppose. I've never done such though.

If anything, my setup should be too high if one thinks about it. I've got 3 stainless steel rectangular bowls that each hold over a gallon of water. From there I then have a 20-gallon rated Aqueon/Whisper air pump driving fresh air into the incubator with an air stone in the middle ss bowl. The Igloo cooler I have has a lip inside designed to hold a tray that is used to place lunch meat and other items you don't want falling into ice/ice water. Resting on that lid are 2 1/4in thick clear Lexan panels cut to contour the curved corners of the cooler and rest upon said lip. I regularly have heavy condensation build-up on these panels. However, I don't have condensation build-up within each egg chamber (cambro food boxes) nor within each Ziploc freeze food containers I use to house each clutch of eggs.

Mold's not been an issue, but each season I tear down the incubator and clean it with 91% isopropyl alcohol. Even then I do get some mold and slime build-up, but that's so far (knock on wood) only been on internal structures of the incubator and not within the egg chambers or Ziploc containers.

This all in mind, I know that too low of humidity, should the embryo make it to term, can result in not being able to slit through the shell. I always kept humidity a little higher with crested gecko eggs because of how calcified Rhacodactylus (we'll lump them all into Rhacs for sake here) eggs can be/are. Others, such as chahuoa have heavily calcified shells and keeping humidity high is crucial to being able to slit the egg and even then a number of breeders, large and small, still have baby chewies get stuck in egg.

I saved Damon Salceies' incubator how-to page. I'll see if I can find it and attach the images...

I have the page saved, but failed at saving the images at fullsize vs thumbnails. PM me your email and I can see if I can zip it all and forward over.