What happen to this Irminia?

Goopyguy56

Arachnoangel
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Anywho, it would be interesting to see if the hair comes back after a molt
 

spideyspinneret78

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I could definitely be wrong....but it almost looks like one of those taxidermied specimens. If this is real, it's really strange.
 

DaveM

ArachnoOneCanReach
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This is fascinating! I've checked these photos against references as best I could, and the characteristics and proportions of these spiders appear to check out. I can believe that these really are P. irminia.

I want to float an idea.

We all know that a premolt T is forming a new exoskeleton underneath the old, and that it is secreting molting fluid in the [so-designated "apolytic"] space between the new and old layers. The molting fluid will eventually serve to lubricate the cuticles as the spider slips out of its old skin. But before that, during premolt, enzymes in the fluid digest the supporting [chitin/N-acetylglucosamine polysaccharide] matrix of the outer exoskeleton -- this thins and softens the outer exoskeleton. We can see a bare abdomen darken when the pigmented layer is digested away; instead of reflecting peachy-colored light, the light passes through and is absorbed by newly forming darker hairs and pigmented layers underneath. The shininess we observe is just like the shininess of a blister: a thin, smooth, translucent membrane with fluid underneath.

Well then, what stops the enzymes in the molting fluid -- the enzyme chitinase in particular -- from also digesting and damaging the newly forming exoskeleton?
People have two ideas about that:
1) The new exoskeleton is covered with a hydrophobic film protecting it from aqueous solution enzymes. We can see water bead up on a T that gets wet; it does have some water repellency on the outer surface of the cuticle.
AND more convincingly / interestingly / better confirmed
2) The new exoskeleton is covered with a secreted protein called Knickkopf that specifically inhibits chitinase. (Here's a paper on that topic: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3193238/ )

So looking at these photos, it seems to me that the newly forming exoskeleton was not protected from the molting fluid enzymes. There are some setae remaining on the tarsi, but mostly the setae are all gone. The thin, hairlike setae have a high surface-area-to-volume ratio and could be accessible to enzymes from all sides, and I think they would be digested away long before the exoskeleton armor plates below.

I think these spiders have a defect in the mechanisms that protect the newly forming exoskeleton. If it is as OP says, that this happens to a population kept in the Philippines, then it is probably genetic. It could be a mutation in the Knickkopf gene, or in the promoter of that gene that causes insufficient production of the protein. I feel that there is a slight chance that this mystery could be solvable. If anyone wants to mail me a sample that I can extract DNA from ( a dried molt would suffice), I could PCR sequence Knickkopf and the promoter region. I would compare the sequence with my P. irminia, which are normal and beautiful. Also, curious, question to the OP: if you spray mist water on your hairless spider (yes, I know it won't like it, but this is for science), does water bead up on the exoskeleton as it does with normal Ts?
 

mosca9tails

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Also, curious, question to the OP: if you spray mist water on your hairless spider (yes, I know it won't like it, but this is for science), does water bead up on the exoskeleton as it does with normal Ts?
It does heres the photo(sorry im still new to this 😅)
And YES IVE GOT PERMISSION FROM THE OWNERS OF THIS PICTURE thanks 😃

Here’s an update as well.
He sent me a video this morning, he also said that his irminia seems to have lost its ability to climb smooth surfaces like completely.
Heres a link as well
 

DaveM

ArachnoOneCanReach
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Yes, thanks, water repellent intact. This might direct suspicion to the Knickkopf protection being defective.

Losing the ability to climb smooth surfaces is interesting as well. Tarantulas have tarsal scopulae -- foot pads made of dense, very fine [microscopic] hairs. The hairs spread out over smooth surfaces [like glass] and help the feet stick by van der Waals forces, molecule-molecule attraction. I suspect that the loss of climbing ability is caused by losing the hairs in the scopulae also. I wonder: are the tarsal claws normal? I don't suppose your friend could get us a magnified photo of the very ends of the spider's feet?
 

mosca9tails

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I could definitely be wrong....but it almost looks like one of those taxidermied specimens. If this is real, it's really strange.
Yup definitely strange. At first we thought that it is taxidermied, some thought its a trapdoor spider

Yes, thanks, water repellent intact. This might direct suspicion to the Knickkopf protection being defective.

Losing the ability to climb smooth surfaces is interesting as well. Tarantulas have tarsal scopulae -- foot pads made of dense, very fine [microscopic] hairs. The hairs spread out over smooth surfaces [like glass] and help the feet stick by van der Waal's forces, molecule-molecule attraction. I suspect that the loss of climbing ability is caused by losing the hairs in the scopulae also. I wonder: are the tarsal claws normal? I don't suppose your friend could get us a magnified photo of the very ends of the spider's feet?
Ill try to ask for a close up photo of it.
Ill keep you guys updated

the owner replied and heres the update
The Irminia(the one in the video) was an import (probably from Europe)
It molted in a temperature of 28-32 degrees celsius
The tarantula ate yesterday
Also, the guy has a few avicularias in his collection that are doing well (big deal because avics are really difficult to keep here in the Philippines because of our the weather, temp here are now reaching 40 degrees celsius)
 
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DaveM

ArachnoOneCanReach
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Molting at 28-32 °C would be just fine for P. irminia. They come from the tropical rainforest area of southern Venezuela, Guyana, and into northern Brazil: => routinely hot and humid.

I don't see anything we can do for these spiders except hoping that they can make it through the next molt, and that the next molt will be less problematic.
Best wishes to you and your friend. 🌈
 

Chebe6886

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I would bet money on this being some kind fungal/bacterial infection. The things in common, I believe, Is that they are from same region. Also in every pic seems to be very humid/wet, this may not have always been the case prior but going off what I see.
Both of these points support an opportunistic infection. That could inhibit setae growth in any number of ways.
 

DaveM

ArachnoOneCanReach
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I would bet money on this being some kind fungal/bacterial infection. The things in common, I believe, Is that they are from same region. Also in every pic seems to be very humid/wet, this may not have always been the case prior but going off what I see.
Both of these points support an opportunistic infection. That could inhibit setae growth in any number of ways.
Please bear in mind that the photo with water droplets on the spider was done because I asked them to test spray with water to check if the exoskeleton was still water repellent. No doubt it is humid in the Philippines and in Venezuela.
 

Chebe6886

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Please bear in mind that the photo with water droplets on the spider was done because I asked them to test spray with water to check if the exoskeleton was still water repellent. No doubt it is humid in the Philippines and in Venezuela.
I had saw you asked for that one instance but the enclosure/s I saw pics of had drops on the wall. While these animals do come from humid environments they do not live in humid plastic containers. As we know with a Avicularia they come from humid locations but will suffer in a overly humid/damp enclosure. I could very well be wrong but infection just makes too much sense in this situation. If a fungi/yeast/or bacteria was able to invade the space between developing and old exoskeleton I could absolutely see something like this being a result. OP asked for possible causes and I feel infection definitely is a possibility elevated humidity or not. Bc Ts don’t go to vets I can only imagine there is a whole host of pathology and sicknesses almost nothing is known about
 
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