Egg Growth

Chris Anderson

Dr. House of Chameleons
I had a female Trioceros montium drop a clutch today. Its the third clutch she's dropped for me and I've bred her to my male a couple times now. You don't realize how much eggs grow during incubation sometimes. These two clutches are both from the same female Trioceros montium. On the left you see a clutch that is 2 hours old and on the right, you see a clutch that is 162 days old:

3648839066_71efbeedd7_o.jpg


Its amazing how much the first clutch of eggs has grown! And here's the female after she finished laying:

3648034307_4aa3795983_o.jpg



Chris
 
Chris,

Do you use small grade vermiculite? Do you notice any difference between that and large grade vermiculite in effectiveness?

Kev
 
Kevin,

To be honest, its been so long since I used the large grain stuff that I couldn't say I could tell you if there was any difference or not. I don't have a problem with the small grain vermiculite and wouldn't hesitate to recommend it to anyone, however.

Chris
 
Chris,

Do you use small grade vermiculite? Do you notice any difference between that and large grade vermiculite in effectiveness?

Kev

We experienced problems with small-grade vermiculite in crocodilian incubation (Crocodylus intermedius), as it became compacted too quickly and created a film of sediment on the contact surface, causing faster desiccation (and possibly a more limited gas exchange). I have since used medium to large-grade vermiculite for incubating anything, and have had great success.

Cool photos...

Fabián
 
We experienced problems with small-grade vermiculite in crocodilian incubation (Crocodylus intermedius), as it became compacted too quickly and created a film of sediment on the contact surface, causing faster desiccation (and possibly a more limited gas exchange). I have since used medium to large-grade vermiculite for incubating anything, and have had great success.

Cool photos...

Fabián

Interesting, Fabian. Are you sure it was the small grade vermiculite in general that was the problem rather then something in the vermiculite that caused the film to build up? I've never had a problem but I'll keep an eye on it. Also, considering how anoxic the environment is where eggs are naturally laid (buried under compacted soil), how much would gas exchange need to be limited for it to make a big deal?

Chris
 
I no longer use vermiculite for incubation media for two reasons, one being that it tends to hold moisture a litte too well for my liking, many instances of egg moulding and of over absorbtion of moisture by the eggs for myliking, though experimentation with it, using a course perlite layer on top yeilded better results.

The second issue with it was post hatch, having small dragons, and pythons become covered with it prior to discovery and in one instance personally having a hatchling asphixiate after filling its mouth/throat with it.

I prefer sphagum moss, which seems ideal, not only for its mould inhibiting properties, but lack of compaction and even moisture distribution below the eggs. It also serves well
to sheild eggs from moisture droples from the box lid (used as a thin layer ontop of eggs)
seems to absorb moistre more evenly, preventing wet spots.

(think of the effect you get when you dip paper towel in a spill and the moisture spreads through the paper, the same seems true of sphagum moss, all drier moss will absorb, rather than just a spot of dampness.)

I have never lost a fertile egg using sphagum moss, no mould, and no issues with moisture content, you dont have to weigh it when preparing eggs boxes, Aka 1:1 like vrmiculite, simply soak it and squeeze dry till it forms in your hand, and thatsabout perfect, no need to make adjustments during incubation, provided you seal the containers. (lids can be removed breifly once a week or so for oxygen exchange and replaced)

Intresting photos chris, Ive noticed a few species egg growth is similarly impressive, some dragons, legless lizards, and colubrids eggs begin quite small (large in number)
and increase size 200% or more, in much shorter incubation periods too. I do note these
lizard species, and ofcourse the colubrids(tree hollows), all lay egg chambers in loose debris and/or soft soil, leaf litter or loosly dug sand burrows, So I presume
a good gas exchange rate and A need for room for the clutch to expand.

Something noteable however, is that all the above are warm climate species.
cheers
 
Interesting, Fabian. Are you sure it was the small grade vermiculite in general that was the problem rather then something in the vermiculite that caused the film to build up? I've never had a problem but I'll keep an eye on it. Also, considering how anoxic the environment is where eggs are naturally laid (buried under compacted soil), how much would gas exchange need to be limited for it to make a big deal?

Chris

Hey Chris,

You raise a good point. I don't know how much gas exchange is present in a chameleon egg during incubation, but in our experience working with Orinocos, the sediment left by the vermiculite at the point of contact (which was about 50% of the egg) was very very obvious, leaving a very thin, shiny film of the mineral across the whole surface of contact. After experimenting with a few other media (sand, sand/coarse vermiculite, coarse vermiculite), we found that the eggs did not desiccate as easily, and we came to the conclusion that the film created by the vermiculite might have reduced the permeability of the egg, thus preventing it from absorbing water properly. You can see this phenomenon when you squeeze vermiculite between your fingers. This may not be such a big issue for the smaller eggs of chameleons, but I feel more comfortable with the amount of space created by coarse vermiculite, which allows the egg to be in less direct contact with moisture.

Something else to keep in mind is that crocodilian eggs, as you know, have a hard shell, similar to those of chelonians, so that might have increased the effect of the sediment sticking to the surface of C. intermedius. It would be interesting for someone to run some controlled tests on this with calyptratus eggs or something.

Cheers,

Fabián
 
Back
Top Bottom