Jack Frost Nipping At My Embryos

My first thawed hatchling, Mr. Freeze, moments after emerging with the desire to rule the world (as soon as he got a little extra warmth from my finger)

Two weeks ago our building decided to test its emergency power generators.  They assured us there should be no problems (never the case) and that electronics plugged into emergency wall sockets shouldn’t have a disruption in power while others might experience small outages that evening.

We assumed our incubator was in the emergency socket and had little concern to think that any disruption to power would cause problems.  Needless to say, that was not the case.  There was a surge when the power came on and according to the repair tech it fried 2 boards… however when power was restored instead of returning to its preset temp, room temp, or even remaining off, it decided to turn on and drop the temp to freezing (or below) (we are unsure of the exact temp as the display board was one of the 2 that fried).  Everything inside was covered in frost and ice including the few remaining eggs I decided to spare from embryo extractions and allow to hatch for breeding next year.

I was sure that they were all lost.  I had no doubt they could withstand brief cold snaps (and even seen TX spiny lizard eggs become completely solid through desiccation and fully rehydrate with the embryos still living), but had little expectation of these little anoles surviving a rapid freeze.  I can’t begin to express how frustrated I was thinking I had lost all these eggs I had set aside for the last 6 weeks and were sooo close to hatching.

I quickly made a makeshift incubator putting them in a closed chamber with warm water to provide heat and humidity, and after being severely annoyed for most of the day, I decided to just let them continue like this until they either hatched or rotted.

I must say I am impressed by the durability of these little guys as we now have 12 adorable hatchlings running around happy and green and 1 remaining egg eagerly waiting to pop.

Since they have survived a harrowing near death experience I must also assume they have been born with super-lizard powers and have given them appropriate names such as “Mr. Freeze,” “Sub-Zero,” and “Bobby Drake” (aka Iceman).  Time will tell if we will see their powers develop and mature.

Mr Freeze and Sub-Zero sizing each other up for future battles to come...

Now an interesting addition to this story: I was telling the guy who collects anoles for us in Louisiana about what had happened and he was not at all surprised.  He claims to commonly find new hatchlings early in the spring season whose eggs must have wintered and just recently hatched.  He also says he knows this is possible because a few eggs will fall into cracks in his large holding pens, where he houses the animals he collects, and in the spring he will find that the ones he missed or couldn’t reach will often hatch out once it begins to warm again.

I had never heard of carolinensis doing this before (though I know it can occur in a few other reptiles).  Considering these guys can often hatch in 4 weeks, going into winter stasis didn’t seem like something they would need to do since it would affect only the very latest clutches of eggs, and extending a 4-6 week incubation period to 4-6 months is quite impressive.

About chadwatkins

Chad is a PhD student at the University of TX @ Arlington researching the influence of transposable elements within the Anolis carolinensis Hox clusters on Hox gene expression and adult skeletal morphology.
This entry was posted in Natural History Observations, Notes from the Field and tagged , , . Bookmark the permalink.

3 Responses to Jack Frost Nipping At My Embryos

  1. Rich Glor says:

    Cool story. I’m not sure our tropical anole eggs would fare as well… How long were they likely at a freezing temperature?

    This reminds me of Jonathans paper on immersing anole eggs in saltwater (pdf).

  2. chadwatkins says:

    I don’t believe they were frozen for too long. Conservative estimate around 6 hours (but I would have assumed that to be sufficient to do damage). There was a 12 hour window from when the power went off to when we found them the next morning. It was a large upright incubator and I assume it would take 1-2 hours to drop to freezing temps. Plus I had my eggs on a rack inside a small Styrofoam cooler with ~1/2 inch of water to maintain humidity, and I figured another 2-4 hours for that to reach freezing as well.
    There was ice/frost on the eggs so they did freeze… I almost opened one then just to see if the embryo was still alive and to see if it was actually frozen solid, but now I’m glad I let them go and as of yesterday they have all hatched out.

  3. Barry Cogen says:

    I’ve actually seen 2 instances where A. carolinensis eggs have survived surprisingly low temperatures. The noteworthy one was from January of last year. We saw record lows for South Florida, with a sustained air temperature of under 30F for a few hours. The next morning I found a pair of unburied eggs on loose soil against a fence line. Not expecting anything to have survived the night before (let alone the previous week of cold), I left them in a bucket on my patio. 18 days later I was shocked to find they had both hatched, and looked otherwise unharmed by the cold. I offered wingless fruit flies (I felt bad for them, what can I say) which they ate a few of, and I sent them on their way.

    My amateur weather station feeds into weatherunderground.com, and since the numbers matched up with many stations around me I have to assume they’re reasonably accurate.

    I don’t know for sure if they developed cryokinesis, but I can’t otherwise explain these little ice-encased A. sagrei I keep finding…..

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