Complex and surprising molt of adult female Brachypelma klaasi - Report

[OldFlash]

Hey folks, everything okay?

My adult female B. klaasi molted a few days ago, and the process ended up being pretty intense. I took some notes and thought it’d be cool to share here.

It started with her lying on her 4th right leg. She was completely sprawled over it. Since I didn’t know how long she’d been like that, I decided not to mess with her. Better to risk losing a leg than cause a bigger issue by intervening. Still, I kept a close eye on her.



Then, I noticed this on the underside of her abdomen (on the new exo)—a pretty significant tear exposing this white mass.



Honestly, I thought she wouldn’t make it through the molt and would die right there. I didn’t touch her and just let her be. I came back hours later, expecting the worst, and to my surprise, I found her like this:



Completely intact, alive, and gorgeous.
Here’s the exposed area from the process, about 5 hours later:





This female came to me earlier this year, already an adult. Looking closer at the photo of her lying down, you can tell there was already something going on in that area:



A cyst? A wound? I’m not sure.
But the speed of the healing—less than 5 hours—shows just how incredibly complex and fascinating the molting process is.

Anyway, she’s still alive, active, eating, and acting totally normal.
Anyone want to take a guess at what she’s got or had going on in that area?

 

[viper69]

That species is always so gorgeous, they get so large. It sure likes like those "cysts". That group out in the EU think they know what it is. I haven't contacted them, they posted on FB asking for more samples I think last year. Sure would like to know what it is, and what causes it if, our husbandry etc?

 

[OldFlash]

That species is always so gorgeous, they get so large. It sure likes like those "cysts". That group out in the EU think they know what it is. I haven't contacted them, they posted on FB asking for more samples I think last year. Sure would like to know what it is, and what causes it if, our husbandry etc?

Same here, would like to know for sure. I asked her previous owner if he’d noticed anything in the past and nothing.
I’m not familiar with that EU group you mentioned and I’m not on FB 🫠 Do you know if there’s any other way to get in touch besides Facebook?

 

[Ultum4Spiderz]

Hey folks, everything okay?

My adult female B. klaasi molted a few days ago, and the process ended up being pretty intense. I took some notes and thought it’d be cool to share here.

It started with her lying on her 4th right leg. She was completely sprawled over it. Since I didn’t know how long she’d been like that, I decided not to mess with her. Better to risk losing a leg than cause a bigger issue by intervening. Still, I kept a close eye on her.

View attachment 495194

Then, I noticed this on the underside of her abdomen (on the new exo)—a pretty significant tear exposing this white mass.

View attachment 495195

Honestly, I thought she wouldn’t make it through the molt and would die right there. I didn’t touch her and just let her be. I came back hours later, expecting the worst, and to my surprise, I found her like this:

View attachment 495196

Completely intact, alive, and gorgeous.
Here’s the exposed area from the process, about 5 hours later:

View attachment 495197

View attachment 495198

This female came to me earlier this year, already an adult. Looking closer at the photo of her lying down, you can tell there was already something going on in that area:

View attachment 495199

A cyst? A wound? I’m not sure.
But the speed of the healing—less than 5 hours—shows just how incredibly complex and fascinating the molting process is.

Anyway, she’s still alive, active, eating, and acting totally normal.
Anyone want to take a guess at what she’s got or had going on in that area?

I lost a few Ts to similar issues.

Underside abrasion help?

I rarely see this happening. I’ve changed the substrate already i noticed the spinnerets looked roughed up a bit too and discolored was some minor mold. It was on 100% Eco earth.

arachnoboards.com

 

[OldFlash]

I lost a few Ts to similar issues.

Underside abrasion help?

I rarely see this happening. I’ve changed the substrate already i noticed the spinnerets looked roughed up a bit too and discolored was some minor mold. It was on 100% Eco earth.

arachnoboards.com

Thanks for the link. And I’m sorry for your Ts.
How did they die? During molts?

Just took some pics of her molt. It looks almost like she was burnt. Pretty weird but very interesting.
What’s crazy to me is how fast it healed. To the point she was able to roll back up with no exposed part coming into contact with the substrate. It blew my mind.

 

[AphonopelmaTX]

Thanks for the link. And I’m sorry for your Ts.
How did they die? During molts?

Just took some pics of her molt. It looks almost like she was burnt. Pretty weird but very interesting.
What’s crazy to me is how fast it healed. To the point she was able to roll back up with no exposed part getting in contact with the substrate. It blew my mind.

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Now I'm going to have to go through my books and digital library to see if I can find some answers. To me it looks like the arthropod equivalent to scar tissue. Good thing I don't have anything going on this weekend.

 

[Ultum4Spiderz]

Thanks for the link. And I’m sorry for your Ts.
How did they die? During molts?

Just took some pics of her molt. It looks almost like she was burnt. Pretty weird but very interesting.
What’s crazy to me is how fast it healed. To the point she was able to roll back up with no exposed part getting in contact with the substrate. It blew my mind.

View attachment 495209

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One died in heavy premolt . The other one randomly just died it was my first lp. It’s 20 gal is still empty I have no space for it.

 

[OldFlash]

Now I'm going to have to go through my books and digital library to see if I can find some answers. To me it looks like the arthropod equivalent to scar tissue. Good thing I don't have anything going on this weekend.

There's no such thing as too much knowledge, you're welcome 🫠🫠🫠

 

[OldFlash]

One died in heavy premolt . The other one randomly just died it was my first lp. It’s 20 gal is still empty I have no space for it.

And were you able to find out what caused both issues?

 

[Ultum4Spiderz]

And were you able to find out what caused both issues?

No one was possibly old worn down topsoil caused the issue. The link above that t had soft eco earth I think possibly mold caused it but I don’t know. I removed the mold and it never improved. Was 10 years old or so.

 

[OldFlash]

No one was possibly old worn down topsoil caused the issue. The link above that t had soft eco earth I think possibly mold caused it but I don’t know. I removed the mold and it never improved. Was 10 years old or so.

It’s a possibilty, no doubt about it. But, tbh, I have a hard time believing it’s substrate related. In my mind, if it was the case, we would have tons and tons of cases like mine or yours.. I don’t know.

It’s weird.

 

[Nitroxide]

I tried to find info on my end - I did find in the tarantula guide something similar about multiple cases in the brachypelma (mostly albopilosus, obviously now as tliltocatl) with either substrate or overfeeding issues causing abdomen abrasions and/or abdominal hemorrhaging. It does look like an old injury so potentially something with the previous owner? But just speculation now.

I also found an article with carapace ruptures during molts so may as well have just been a previous molting injury that is still healing.

It did look pretty gnarly during the molt, though. Happy she pulled through and it looks much better already!

 

[OldFlash]

I tried to find info on my end - I did find in the tarantula guide something similar about multiple cases in the brachypelma (mostly albopilosus, obviously now as tliltocatl) with either substrate or overfeeding issues causing abdomen abrasions and/or abdominal hemorrhaging.

Thanks for your input. As much as I find it hard to believe it’s substrate related, (and only because I feel we would see it happening everyday) it does make the most sense for sure. Maybe some chemical or added material to the substrate that may be harmfull to some inverts?
It does make sense.

. It does look like an old injury so potentially something with the previous owner? But just speculation now.

I agree, it does looks like an old injury, but the guy never noticed anything. He’s a snake breeder, had two tarantulas but was never really into it.

I also found an article with carapace ruptures during molts so may as well have just been a previous molting injury that is still healing.

That’s what I thought at first. And thought that her leg being underneath her had caused it. Then I noticed it was already there before the molt.

It did look pretty gnarly during the molt, though. Happy she pulled through and it looks much better already!

Ii looked pretty bad indeed. Her right chelicerae didn’t look good either. She couldn’t move it, it looked swollen, kind of deformed.. She was a mess.



I’m still surprised she made it 🫠

 

[jennywallace]

Glad your T is fine. My adult female LP has a similar black coloured abrasion on the underside of her abdomen. I noticed it after her last moult, but she's fine and shows no ill effects from it.

 

[Nitroxide]

Thanks for your input. As much as I find it hard to believe it’s substrate related, (and only because I feel we would see it happening everyday) it does make the most sense for sure. Maybe some chemical or added material to the substrate that may be harmfull to some inverts?
It does make sense
.
I agree, it does looks like an old injury, but the guy never noticed anything. He’s a snake breeder, had two tarantulas but was never really into it.

Yeah agreed super weird for substrate especially mostly everyone uses similar types of substrate but maybe even bad batch, who knows. I've never had substrate issues as well and have gone through a lot of changes as I learned about spiders over the years so wouldn't be able to speak from experience for substrate issues. But may as well be an old injury or molt issue, especially with the chelicerae issue as well. Hopefully she recovers well and no issues in the future!

 

[TheraMygale]

It has not happened to me yet. The first thing i thought when i saw that, was scar tissue rubbing. Its at the perfect place too. And its a big abdomen.

it reminds me of the calluses dogs have on their elbows.

now, dont get me wrong here, i have no clue or knowledge on this sort of thing.

its more my thought process that brings me there.

it can obviously be anything, like a tumor, or cysts. but without science people analyzing samples and dissections, we are on standby.

this contribution is very informative. The more we get to look at these abnormalities, the closer we get to having answers.

help Lp with scab on the bottom of abdomen!!!

I was watering my female L. parhybana and decided to take her out and look her over. She hairs when you mess with her too much making me itchy for a week... Anyway i pinch grabbed her and she had a scab on the bottom of her abdomen. Im not sure how long it has been there as i have had her for...

arachnoboards.com

 

[Smotzer]

Wow very interesting, this is probably some of the clearest photos we’ve had of one of these similar issues yet! It does remind me a bit of scar tissue as well just from the appearance.

 

[spideyspinneret78]

I've a few adult females that were overfed and obese when I got them, with similar lesions on the undersides of the abdomen that thankfully weren't this severe. I fed them very very sparingly and with each subsequent molt they lost weight and the lesions healed more. My AF G. rosea now has just a slight blemish where there was once a blackish colored lesion. In one of his videos (or podcasts, I can't remember), Tom Moran had an avian and exotic vet guest speaker who explained that he believed molting injuries and some abdominal sores such as this are caused by obesity and the underlying layers of exoskeleton herniating through the weakened areas, especially during molting. Maybe something similar is going on with your tarantula.

 

[OldFlash]

Wow very interesting, this is probably some of the clearest photos we’ve had of one of these similar issues yet! It does remind me a bit of scar tissue as well just from the appearance.

I've a few adult females that were overfed and obese when I got them, with similar lesions on the undersides of the abdomen that thankfully weren't this severe. I fed them very very sparingly and with each subsequent molt they lost weight and the lesions healed more. My AF G. rosea now has just a slight blemish where there was once a blackish colored lesion. In one of his videos (or podcasts, I can't remember), Tom Moran had an avian and exotic vet guest speaker who explained that he believed molting injuries and some abdominal sores such as this are caused by obesity and the underlying layers of exoskeleton herniating through the weakened areas, especially during molting. Maybe something similar is going on with your tarantula.

Very interesting. First time dealing with this issue. I don’t know much about her past, but since she already had something going on in that area before molting, she was probably overweight at some point in her life.

Hopefully it’s been healing with every molt and not getting worst

 

[AphonopelmaTX]

There's no such thing as too much knowledge, you're welcome 🫠🫠🫠

New knowledge has been assimilated. Wasn't too bad to research, I just forgot to reply.

Turns out, that dark spot in the shed exuvium is more like the arthropod equivalent of a scab than scar tissue. When a terrestrial arthropod experiences an injury such as a puncture or tear in the exocuticle, the arthropod's immune system kicks in and quickly clots the wound with cells in the hemolymph called hemocytes. Following the initial plug, further encapsulation of the wound occurs, and a large amount of chemical reactions take place to produce antimicrobial compounds and to produce a more stable and secure plug. The most important of which is melanin production which turns the affected area dark in coloration and provides the majority of the antimicrobial and antifungal properties. Depending on the stage of new cuticle production between ecdysis the injury, immune reaction, and new melanin rich plug can affect the formation of the new cuticle making the injury appear on the new cuticle even after the molt. Best case scenario is that an injury occurs before new cuticle creation and a spider can shed off the "scab"; worst case scenario is that the immune response happens late in the growth cycle and affects the new formation of cuticle to the point it basically can't heal and the spider bleeds out or an infection sets in.

What is particularly interesting in spider immunology is that their immune system is not adaptive. If the built in biochemical processes that encapsulates the wound, and the resulting antimicrobial and antifungal mechanisms don't work, the spider will get sick and die; they do not produce antibodies. Also what is kind of cool is that the whole process of wound healing is fast and something of an all-in-one solution.

After reading about the process of wound healing in terrestrial arthropods, it all matches up to your own observations. Mainly how quickly you noticed the wound healed itself and how the appearance of a dark area that looks burned matches the description of what a melanin rich plug would look like.