Theoretical role of fungus in egg development.

[Jeweledchameleons]

I wanted to share some thoughts on this subject.
but first some background might be worth mentioning.

Weather people realize it or not, the role of mycological life in the
biosphere is extensive, pervasive and often goes unnoticed by us humans.
Many organisms actually depend upon different assorted fungi to not only
thrive, complete their life cycle -but to even simply survive.

Orchids (for those that don't breed them) require some type of mold or
fungus to be present where their wispy "seeds" settle. So that when the
orchid germinates it can form a symbiotic or even parasitic relationship with
that fungal mat to nourish it in the manufacture and transport nutrients to it.

Plants also use mycological networks to their advantage to increase their
root systems effectiveness 100 times or more. Providing massively
enhanced surface areas, the manufacture and release of nutrients. Not to mention creating
a protective shielding against attack or outside infection.

We all know that many chams (if not all) strongly prefer to lay their eggs
among the base of plant cover.
It's been already theorized that they've evolved to take advantage of what
was described as a "wick effect" from the root systems to regulate water
and gasses to the developing egg cluster. One has to wonder about the
different chameleon species are also using fungus that the conjunction
with the plants to support their egg development.

Those that have bred different chameleons have always viewed mold as a
sign of a dangerous infection. Yet we can easily see that most eggs don't
instantly die from having a fuzzy layer on it. Instead for those that are
"dead" it's quite possible that the many eggs were quite infertile before any
signs of fungus were first noticed.

Although, we currently try to keep the incubation media "clean" and devoid of
anything other than the eggs we're intent upon hatching. I wonder if anyone
has any thoughts upon the use of non-sterile media
deliberately seeded with with either a fungal or bacterial combo culture to aid development.

Yes, I know that this is the stuff of a graduate thesis.

But some thoughts from other members on this subject
might help lift the level of conversation above the discourse
regarding the quality and consistency of "what's appropriate for chameleon droppings" around here...

 

[Sepioteuthis]

Interesting topic. I'll throw a few cents at it.

I've only incubated 2 clutches of chameleon eggs (R. brevicaudatus & Ch. melleri) and only observed fungal growth in one of them. I'll describe both situations and then give my opinion on what I think this shows aboutthe relationship between fungus and eggs.

The brev eggs; I found the eggs by accident when remodeling the brev enclosure. Because I didn't now how far along the eggs were I scooped them out with the surrounding soil and incubated them like that. This soil had been in the brev inclosure for more than six months and clearly was anything but sterile. In the next 3 months of incubation there was no visible fungal growth at all and all three eggs turned out to be fertilized (2 hatched, 1 died duringthe hatchling process).

The melleri eggs I dug up right after they were laid and these I incubated in a more traditional manner (sterilized vermiculite) although I didn't wipe the egglaying substrate (peatmoss) off the eggs. After about three weeks a number of eggs started to shrivel up - these eggs were all covered with fuzzy fungus. In the course of incubation there was some fungal growth on the viable eggs, however the fungus seemed to be growing on the bits of peatmoss that where on the eggs rather than the eggs themselves. There didn't seem to be a correlation between the presence of this little bit fungus on the otherwise heathly looking eggs and the hatching success (some hatched, some didn't). However the bad eggs all ended up covered in fungus sooner or later.

Overall, based on my limited experience I think that instead of using or needing the fungus, the viable eggs may actually repel the fungus. I think the benefit of laying eggs among roots is that it protects the eggs from accidentally being exposed during incubation, in addition to the improved airation that you mentioned. This inadvertently means that the eggs are layed in a fungus-heavy environment from which heatly eggs seem to be able to protect themselves.

 

[Jeweledchameleons]

I generally agree with what you've said above.
However there are many different species of fungus that can infect buried eggs.
There are also those that wouldn't bother them at all.

I would protect against any of the aggressive species that would make
a meal out of any protein they came into contact with
while I can imagine that some of the more benign mycorrhizal fungi
might have more of a positive effect.
At least protecting the egg cluster from the invasion of a more aggressive
species that would consume the egg mass.

The practical problem is how and if a active mycorrhizal fungus could be
brought into an egg incubation culture to test.

Granted that this is all academic since experienced individuals hatch rate are satisfactory.
But it may serve as an option for those trying to hatch an infected clutch
where the use of commercial fungicides can't be used.

All in all, this is just an example of my mental wanderings