Mold on cork bark!? What should I do? What do I do wrong?

[Hagazpacho]

Hi! I have recently found this on the inside of Lucifer's hide, I'm afraid it's mold... what should I do? Clean it, throw it out? I don't know how it got there, I have good ventilation and I do what the breeder I bought from said, I water the corner of the substrate, and water it again when it dries out. Could this be the problem? If so, what do you guys recommend to keep him/her (L. Parahybana) at a healthy humidity? Thank you!

 

[boina]

That's not fungus, that's lichen. It grows on cork bark.

And kind of humidity, or lack thereof, is healthy for a L. parahybana. Humidity numbers are arbitrary and are likely to induce you to keep your tarantula too wet. They just need a bit of moisture here and there, like you are doing, and that's it. After all, they are spiders and not reptiles. Do not, and I repeat: DO NOT let the enclosure get too moist. These are much easier to kill by too much moisture than by too little.

 

[Hagazpacho]

That's not fungus, that's lichen. It grows on cork bark.

And kind of humidity, or lack thereof, is healthy for a L. parahybana. Humidity numbers are arbitrary and are likely to induce you to keep your tarantula too wet. They just need a bit of moisture here and there, like you are doing, and that's it. After all, they are spiders and not reptiles. Do not, and I repeat: DO NOT let the enclosure get too moist. These are much easier to kill by too much moisture than by too little.

Hi! Sorry, the picture might not show what I thought of, I was thinking about this white fuzzy stuff on the wood, but if that is lichen, then I will be relieved

 

[boina]

That's really hard to see, but if you have mold growing on cork bark you have a real problem, not because of the mold - that's hamless enough - but because mold does not grow on cork bark unless you have an overly moist, stuffy environment that's really unhealthy for your tarantula. You shouldn't be worried about the mold (harmless!) but you should really worry about what you did to get it there.

As I said, I'm not sure it's mold.

 

[Teal]

I'm not seeing any mold...

 

[Spidermolt]

You can just boil the cork bark in a large pot for a few minutes them let it sit out and dry for a few days until its bone dry. Bye bye mold

As for how the mold got there your substrate looks like it has way too much moisture, make sure you have enough ventilation and let the substrate dry out a bit or just but in new substrate all together

 

[Hagazpacho]

Thanks everyone!

 

[The Grym Reaper]

If it's been set up relatively recently then you might get the odd bit of white fuzz pop up here and there, it's pretty much a non-issue as it generally uses up any nutrients in the sub and dies off shortly after.

 

[viper69]

So maybe, just maybe people who post nondescript pictures should think it helpful by putting arrows on what we are to look at. It's crazy idea I know...like breathing.

 

[AphonopelmaTX]

... unless you have an overly moist, stuffy environment that's really unhealthy for your tarantula.

I don't fully understand the reasoning behind this statement. Maybe I don't understand the context in which it is written though. Most ground dwelling tarantulas are fossorial by nature and depending on where they occur naturally, can spend their entire lives or a significant amount of it in a closed, damp, stuffy burrow deep in the ground. In my experience overly dry conditions in captivity can kill a tarantula of any species quicker than damp unventilated conditions.

Since Aphonopelma hentzi is a species I have observed in nature in the course of a full year, I will use them as an example. In north Texas, the rainy season occurs in early summer and again in late summer through fall. The clay soil these tarantulas live in are saturated several months throughout the year and they live in sealed off burrows in this wet clay. One finds the burrows of A. hentzi sealed more often in a year than open.

So what is special about keeping a fossorial tarantula species in damp stuffy conditions in captivity for an extended amount of time that is unhealthy for them when they live in the same conditions naturally?

 

[boina]

Ok, step by step:

In my experience overly dry conditions in captivity can kill a tarantula of any species quicker than damp unventilated conditions.

My experience is exactly the opposite. My tarantulas and tarantulas of the people I know tolerate dryer conditions significantly better than humid, stuffy ones. There are exeptions to this, of course, like to obligatory moisture dependant species (mainly Theraphosa, Megaphobema, Asian fossorials).

can spend their entire lives or a significant amount of it in a closed, damp, stuffy burrow deep in the ground.

No. Earth is always porous. And not only that, there are worms and stuff in there that make micro-tunnels and move earth and so on. Air gets exchanged all the time. Glas/plastic isn't.

So what is special about keeping a fossorial tarantula species in damp stuffy conditions in captivity for an extended amount of time that is unhealthy for them when they live in the same conditions naturally?

Natural conditions are much different than what you can provide in captivity. The one and most important difference is the microbiota. It has only been studied in more detail in the last 10 or so years. Every natural soil environment has a very specific community of micro organisms living in them. They are absolutely essential in creating a healthy environment. The research about it is abundant, but there isn't really a good introductory level review, so I'm not sure what to cite here. Maybe you can just google a bit around?

My own summary of the situation:
The importance of microbiota cannot be overestimated. They are specific for every environment, even for every micro-environment. Microbiota around plant roots are different than microbiota without access to plants, for example. They consist of bacteria, fungi (often microscopic ones, Protozoa, and microscopic worms. Their specific composition keeps the environment healthy. They are exceptionally good at keeping pathogens in check, plant pathogens as well as animal pathogens. There is even research that they play a major role in keeping allergies at bay (so get your hands dirty, people ) Every animal is of course specifically adapted to the microbiota in the environment it usually lives in, i.e. it receives benefits from interacting with them. Further, it is resistant against the pathogens that may occur among those microbiota. Spiders don't have an adaptive immune system, like mammals, only an innate one, but they have a very specific set of antimicrobial peptides that is geared towards what they'd normally encounter.

Now you take that spider out of it's natural environment and put it in an enclosure with a very poor microbiome, only a few species, and those are nothing like those the organism it is used to. It immediatly loses it's protection against pathogens and who knows whatever else. And on top of that it gets exposed to pathogens that are completely new, that it has never encountered and where its set of antimicrobial peptides may not work.

Now, it is very well known that bacteria and other microorganisms grow much more abundant in moist versus dry soil. So, you have moist soil - a perfect breeding ground for bacteria - and a poor microbiome that can't keep those bacteria in check... The outcome is just logical.

Humidity without the natural microbiota - that are impossible to provide - can spell disaster. That's what people mean by 'humid, stuffy conditions'.

 

[Mirandarachnid]

In my experience overly dry conditions in captivity can kill a tarantula of any species quicker than damp unventilated conditions.

My experience is exactly the opposite. My tarantulas and tarantulas of the people I know tolerate dryer conditions significantly better than humid, stuffy ones.

Could these opposing experiences have something to do with the ambient humidity of the areas you live in?

I live in an arid region, and I have noticed that my T's seem more 'comfortable' with more moisture. When I allow the top layer (2cm) of sub to dry out I notice that they quickly dig down to the moist layers of substrate or start straddling their water dishes (Lasiodora, Nhandu, Brachypelma). Granted, I have been keeping T's a significantly shorter amount of time than either of you, so my experience of trial and error is limited.

If I recall correctly (my recollecting machine isn't in the best condition, mind you), I believe I read @EulersK mention that he keeps things slightly more on the damp side as well, considering he lives in a desert.

 

[boina]

Could these opposing experiences have something to do with the ambient humidity of the areas you live in?

No. Humidity yes, unventilated conditions - no. Moisture + lack of ventilation doesn't work. Explanation see above.

Moisture alone wasn't discussed, so your example is invalid.

 

[EulersK]

If I recall correctly (my recollecting machine isn't in the best condition, mind you), I believe I read @EulersK mention that he keeps things slightly more on the damp side as well, considering he lives in a desert.

You got it. The likes of C. cyaneopubescens can usually be kept 'bone dry', but they would die if kept that way where I live. Very, very few species are kept truly bone dry where I live.

 

[viper69]

In my experience overly dry conditions in captivity can kill a tarantula of any species quicker than damp unventilated conditions.

This is not true for Avicularia.

 

[PhilMcWonder]

Buy some springtails and release them in the cage. they are small and non-invasive to the tarantula. They eat your T's poop, plant matter, mold and fungus. They just require some moist substrate.