P irminia slings from tiny sac keep dying

[darlingi]

My first breeding attempt (P irminia) resulted in a tiny sac of ~15-20 slings. That was around 7 months ago. Today I lost another sling of said sac due to a failed molt (I think), which makes it 6 losses total. It makes me wonder if there’s a thing such as an „unfit“ sac. I’ve had them die in enclosures were I suspected I may have kept them too moist, but also, like in this case, where I have kept them on the dry side.

The sub is dry in the pic, but I had watered part of it a week ago. Because of the recent losses (indicating I might have to keep them drier), I don’t keep slings of this size with water dishes and wet the substrate + webbing instead.

Also; yes it’s definitely dead. I took a look under the microscope and saw mites crawling around. To me it looks like the carapace has been popped, but no further progress has ever been made.
This is how I found her; laying on her side not moving. Maybe she wasn’t even molting and died in a strange position for other reasons (impaction)?

 

[jrh3]

Is it possible that those oak leaves have some type of pesticide on them and if they are wild collected you could have picked up something predatory. Those are nice sized slings, if not juveniles, I would think if it was a sac issue they would have died after the first or second molt.

 

[darlingi]

Is it possible that those oak leaves have some type of pesticide on them and if they are wild collected you could have picked up something predatory. Those are nice sized slings, if not juveniles, I would think if it was a sac issue they would have died after the first or second molt.

I get those leaves from a reputable shop, so I doubt they’re the reason, but I’ve never thought about that tbh. I’ve been using a variety of leaves (not only oak) from said shop, and basically each of my enclosures has them, including the healthy T’s.

I’ve had a lot of „mystery“ deaths and while I’m always first to blame myself, the circumstances or potential causes vary so wildly that I’m not sure anymore in which direction to adjust my husbandry (keep more moist/dry etc)..

 

[Wolfram1]

perhaps the ventilation was adequate for smaller spiderlings but has become inadequate for larger specimens or during stress events like the molt where booklungs are probably working at reduced capacity


its hard to judge, but i don't see any ventilation at ground level and we can't see the top ventilation you use...
is it one of those boxes with pre installed circular plastic grille? Or did you just poke a few holes?

or perhaps it dodnt have enough to drink, dehydration will mostly affect them during premolt/molting if its not extremly severe


what are we supposed to see in the magnified picture?


i personally don't think it was pesticides or any microfauna you brought in, but i can't disregard that either.
here in Austria or even in Germany most forests are fine to collect in.
i'd honestly prefer to collect them myself over buying them as it gives me control over where the leaf litter came from, nor do i treat them to get rid of the soil fauna, fungy, etc. ... never had a problem this way.

in fact i'd be more worried that the leaf litter was treated against mites etc. if it was ment for reptiles....


in terms of how dry/moist you keep them that depends on your ventilation, without that information it essentially impossible to say if there was an issue...

 

[darlingi]

perhaps the ventilation was adequate for smaller spiderlings but has become inadequate for larger specimens or during stress events like the molt where booklungs are probably working at reduced capacity


its hard to judge, but i don't see any ventilation at ground level and we can't see the top ventilation you use...
is it one of those boxes with pre installed circular plastic grille? Or did you just poke a few holes?

or perhaps it dodnt have enough to drink, dehydration will mostly affect them during premolt/molting if its not extremly severe


what are we supposed to see in the magnified picture?


i personally don't think it was pesticides or any microfauna you brought in, but i can't disregard that either.
here in Austria or even in Germany most forests are fine to collect in.
i'd honestly prefer to collect them myself over buying them as it gives me control over where the leaf litter came from, nor do i treat them to get rid of the soil fauna, fungy, etc. ... never had a problem this way.

in fact i'd be more worried that the leaf litter was treated against mites etc. if it was ment for reptiles....


in terms of how dry/moist you keep them that depends on your ventilation, without that information it essentially impossible to say if there was an issue...

I have actually rehoused most of the slings a few weeks ago because I was worried the ventilation in their previous enclosures (little vials with only top ventilation) was not enough. So I doubt it’s not enough ventilation. I‘ll add a picture.
The substrate is not bone dry, there’s some moisture still. But still, I was leaning more in that direction; that I kept them too dry. They get water in one corner every few days (1-2x a week) since I cut down on keeping them as moist as before. As already mentioned, due to recent losses from that sac I was previously actually worried I might’ve kept them too moist before the rehouse, which is why I went on keeping them on the dry side.

I got the leaves from arachno-world.shop, which you might be familiar with since you're from Germany/Austria as well. I very much doubt they're treating anything since they're a dedicated T breeder.

Regarding the microscope pic; to me it looks like the carapace has slightly detached from the body. I added that because I am not even sure if she actually started molting, or just died in a weird position with a huge, shiny abdomen.

The rows of holes are on 3 sides of the enclosure:

 

[fcat]

It may help to drudge up some details on the other mystery deaths. Did they have anything in common? Same materials, where they were at in their molt cycles, position you found them in (death curl, dead right there, died during molt), getting direct sunlight, ages/size of specimens when they perished?

I see what you mean with the carapace looking separated, not on the scope but when zooming in on the position you found her.

There may be some pertinents that the experts will pick up on, I say it's worth detailing. Example, If any of the other Ts have been lost while molting then you would need to consider possible pesticide exposure as the mechanism of some is to cause death when molting, I think @The Snark

I just want to say I'm sorry this is happening with your first sac.

 

[darlingi]

First of all; thank you, I really appreciate that. This is taking a huge toll on my mental health so it feels good to read something empathetic.

For the other P irminia deaths: I have not found any of them dead in the process of molting. They were just unresponsive and not even in a death curl iirc. Usually looking like a still T but crawling with mites having a feast.

I’ve already mentioned that I was suspecting mistakes on my side regarding the moisture levels, but for the irminias I’ve had deaths in the little sling vials (4 I think) and now 2 in the bigger, drier enclosures as well. So I’m not sure in what direction to adjust my husbandry.

To put it in the bigger context of the other other mystery deaths; I’ve had a terrible streak of losses in autumn 2022 where I lost 3x C brachycephalus, 3x C fimbriatus and 2x C natanicharum. I remember finding the C natanicharum in dried out enclosures after I had failed to realize that the dry winter air had kicked in, so I assumed those were on me.
All of them were slings smaller or the same size like the irminia.

1 C fimbriatus died in a similar way like the P irminia in this thread; with a huge abdomen and not in a death curl. The day before it was only slightly responsive and remained in a weird threat pose-like position. Next morning it was dead. I was suspecting impaction back then.

There was one H pulchripes that was in a molting position (if I remember correctly) but ended up dying over night. That was in 2023.
Size was a bit bigger than the irminia.

Lost a juvie H mac about a year ago to what I think was too much moisture and an OBT with some kind of molt issue (old skin over abdomen, lethargic and dead a few days later).

Materials, feeders and substrate used were the same as in enclosures with healthy Ts

They are never in direct sunlight and I’m a pretty paranoid keeper in general, so no spraying of perfume or stuff like that in the vicinity of the Ts. I also can’t imagine how they’d come in contact with pesticides since I’m super careful when it comes to that stuff

 

[fcat]

Hopefully something stand out to someone.

I am probably guilty of keeping my Ts moist-er than they need to be...but paired with adequate ventilation, it's something I'm always chasing because I live in the desert and it's dry as heck here. To further offset that, I give more substrate so it can hold onto moisture longer.

For small slings my first order of business is getting them out of the sling vial and into something with cross ventilation, with some at the substrate level. I've got a teeny C natanicharum still in his because he did his home so well and he's premolt, but I pop the top every day or so (I work 24 hour shifts) and rotate it a bit, so I "catch" the gentle breeze of the ceiling fan. Is it dumb, yeah, but I want to make sure there is some air exchange at the bottom.

Substrate can be dry and deceivingly dark/wet looking. I'm always picking up the little guys' enclosures to monitor the weight.

Give this a gander, in case it helps

The Husbandry of Moisture Dependent Slings

DISCLAIMER: This writeup is specifically for the husbandry of moisture dependent slings and I’m going to be talking about the controversial topic of *humidity*. If you would like to argue about the merits of its application or importance in the husbandry of moisture dependent species, please...

arachnoboards.com

 

[darlingi]

Hopefully something stand out to someone.

I am probably guilty of keeping my Ts moist-er than they need to be...but paired with adequate ventilation, it's something I'm always chasing because I live in the desert and it's dry as heck here. To further offset that, I give more substrate so it can hold onto moisture longer.

For small slings my first order of business is getting them out of the sling vial and into something with cross ventilation, with some at the substrate level. I've got a teeny C natanicharum still in his because he did his home so well and he's premolt, but I pop the top every day or so (I work 24 hour shifts) and rotate it a bit, so I "catch" the gentle breeze of the ceiling fan. Is it dumb, yeah, but I want to make sure there is some air exchange at the bottom.

Substrate can be dry and deceivingly dark/wet looking. I'm always picking up the little guys' enclosures to monitor the weight.

Give this a gander, in case it helps

The Husbandry of Moisture Dependent Slings

DISCLAIMER: This writeup is specifically for the husbandry of moisture dependent slings and I’m going to be talking about the controversial topic of *humidity*. If you would like to argue about the merits of its application or importance in the husbandry of moisture dependent species, please...

arachnoboards.com

You wouldn’t believe how often I have looked into that thread over last few months It’s good advice but it still doesn’t really help anymore because right now it feels like they die either way, no matter if kept moist or on the dry side.

As for the substrate; in the case of the dead irminia, the substrate still had some dampness in the lower levels left (I’m also a fan of deeper substrate to provide a way of „storing“ moisture). Not much moisture, but to a degree where the substrate feels a tad „cold“ to the touch and sticks to the hand. Last time I added water was like a week ago maybe? Anyway, she shouldn’t have been dry for more than a couple of days, worst case.

Given that she looks super plump, not dehydrated at all, I’m wondering wether they really are that fragile to fail a molt after drying out for a couple of days, when they regularly do get moisture. But again; I’m not even sure if she was molting, since she’s right out in the open and not in her web tube.

 

[fcat]

Do you breed your own feeders?

 

[darlingi]

Do you breed your own feeders?

No, for the slings I exclusively feed mealworms that I keep in the fridge and go buy some more when they are running low. I have also suspected the mealworms for a while, but then again I also feed them to many of my juvies and they are all doing well.

 

[The Snark]

Sounds like the gamut of suspects has been well examined. Unless some smoking gun surfaces; Bio 101. Genetics doing exactly what they are supposed to do, removing defects from the gene pool.
With any anomaly before or during gestation, barren, un-thrifty, or birth rate outside of the norm and so on, some defect is suspect. In this case, the female, roughly analogous to a human female producing a suspected defective amniotic sac.

 

[Brewser]

Translation - Survival of the Fittest ( Natural Selection )

 

[Ultum4Spiderz]

My first breeding attempt (P irminia) resulted in a tiny sac of ~15-20 slings. That was around 7 months ago. Today I lost another sling of said sac due to a failed molt (I think), which makes it 6 losses total. It makes me wonder if there’s a thing such as an „unfit“ sac. I’ve had them die in enclosures were I suspected I may have kept them too moist, but also, like in this case, where I have kept them on the dry side.

The sub is dry in the pic, but I had watered part of it a week ago. Because of the recent losses (indicating I might have to keep them drier), I don’t keep slings of this size with water dishes and wet the substrate + webbing instead.

Also; yes it’s definitely dead. I took a look under the microscope and saw mites crawling around. To me it looks like the carapace has been popped, but no further progress has ever been made.
This is how I found her; laying on her side not moving. Maybe she wasn’t even molting and died in a strange position for other reasons (impaction)?
View attachment 472876

I had a similar issue with obt and t gigas back in the day weak bloodlines it seems I was sold . Sorry … I had it happen to other species including yours too.

 

[darlingi]

After having lost 3 more irminia slings „randomly“ I was ready to just believe it’s a weak sac but just now I randomly found my precious balfouri female dead. I can’t believe it. She was acting weird for a few weeks but I brushed it off as her being in premolt. Her abdomen looks wrinkled, but the irony is that I actually gave her water more regularly than usual over the last few weeks because I assumed the molt was coming.

Not like I flooded the enclosure or anything, but it’s not like she was weeks without water. She loved to web the water dish so I resorted to water the webbing. She was super plump the last time I checked on her. She even had 2 dead mealworms in her enclosure from the last time I attempted feeding her. Does anybody have an idea what could be going on here? I’m going insane

She didn’t die on the water dish btw, I just moved her there for the pics. Position was also a classic death curl, not as chaotic as pictured

 

[darlingi]

Looks like there’s some sort of crust on the inner side of one of her legs. Possibly an injury?