Poecilotheria tigrina Egg Sacs

I currently have 6 Poecilotheria females sitting on sacs: 2 fascata, 2 regalis, and 2 tigrina. In the last year I've hatched out 2 regalis and 1 ornata sacs. In all of this activity, the norm is for the females to make a silk chamber under a cork slab, spin a thick mat on the bottom, lay her eggs on that, then roll up the silk and eggs into a ball. They tear down the silk chamber and can come out if they want (maybe for an occasional drink or snack). But not the tigrinas. Both females are still sealed in their silk chambers a couple weeks later. Never seen this before. I'm wondering if in their native habitat this is done to hold in moisture during the dry season, or to keep out predators. Or maybe because they'e one of the 4 Poec species whose slings have an extra instar in their development and they give them extra protection. Anyone else have their Poec females do this?

BTW, I take out their water bowls when they have a sac. Over the winter I had an ornata discard her sac into her waterbowl just before I was going to pull it at the 30 day mark, and drown all her EWL's. Broke my heart to see all those lifeless little spiderlings. After that episode, they lose their waterbowl priviledges while they have sacs. Not going to risk it again.

Hey Poec54,
I have two P. regalis females currently holding sacs and they both have done exactly like your tigrinawesselis. All completely sealed up in their web chambers. One sac will be ready to pull in a couple days so she has stayed in a full 30 (or will be tomorrow). They are my first try at Pokie breeding so I didn't know the behavior was much out of the ordinary. Wonder if it could be the way I have the tanks set up or temp/humidity conditions? Interesting though.

I have also had regalis seal themselves in. Pretty sure my rufilata did the same.
Can't remember seeing the others sealing themselves in for the full incubation (I let the females hatch their own sacs)

Okay, so it's not a tigrina-only thing. Evidently there's a trigger for Poecs to do it; maybe a combination of temp, humidity, etc. Certainly keeps out some potential intruders, and may keep their scent contained so it's not an attractant to predators. The youngsters would have a protected playground to start life in. Now, if we can just figure what makes them maintain that sealed chamber, when others don't.

I think it might be to keep predators out, i have had offspring of many poecs and i dont see any differences between the ones who have 1 instar og the 4 who have an extra. I dont say that there is never any differences, but i have not seen any.

I know your asking about poekies but my P irminia and my C fasciatum did the same thing completely web their selves in for the whole time they were on a sac. So its not just a poekie thing either. I was thinking it may be to lock the humidity in as well. But extra protection from predators would make sense as well. Maybe they do it for multiple reasons.

A little late on this post, but here goes. I interpret the building of silk chambers as you have put it as a sign of the spider's insecurity in it's enclosure. In my experiences with Poecilotheria, a cork slab propped up against the side of a container is not a suitable hide for a Poecilotheria species.

When a tube of cork bark with a diameter of several inches has been provided to my individuals of Poecilotheria spp., they took up residence and came out only to feed. When provided a slab of cork bark propped up against the side of the enclosure or a cork tube with a diameter of a couple of inches, they spun "tents" under it to create a more secure hide for itself or didn't use any silk at all. With a cork slab, sometimes mine would just hide behind it. In an adequately sized cork tube, web was used as a lining and to seal off the opening. A determination of security is based on the principle of "a happy spider is an invisible spider." My own observations tell me a Poecilotheria species needing a tube to hide in is basically the same as providing a Haplopelma species with deep substrate to burrow in. An obligate burrower will construct silk chambers in it's enclosure too if it didn't have the proper conditions to give it a sense of security.

In the case of egg laying I would think that a tarantula that would otherwise not spin any silk retreat would make one at that time to provide more security for itself and the eggs. I don't believe any of what was mentioned was to regulate environmental conditions but more to provide a safe place to construct and care for the egg sack. I believe our enthusiasm for our tarantulas causes us to over analyze their behavior at times. That being said though, I wouldn't totally discount environmental regulation either. It's always a possibility. Also, there are far too many variables in captive conditions to tell what the threshold of a sense of security and insecurity is to a tarantula. It would be impossible to know why exactly one individual would create a silk chamber and another wouldn't.

AphonopelmaTX said:

My own observations tell me a Poecilotheria species needing a tube to hide in is basically the same as providing a Haplopelma species with deep substrate to burrow in.

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How many Poec sacs have you hatched out and what species? I want to get a feel for how much of this you've seen.

I'm not at all an expert but i happen to have some poeci's and a couple of them are paired females. 3 of them did web for having an egg sac i think. 2 of those have an hollow cork tube an the other just some cork against the glass and that one webbed like crazy.

Here some pics :

P. miranda in tube (which i think has an egg sac atm):


P. regalis also in tube without an egg sac :


And the P. subfusca without a tube, which had a sac but i don't see it anymore :


All 3 stay in there from the moment they 'closed' it but the P. subfusca came out yesterday late at night, so that's why i went checking and didn't spot the egg sac anymore...

David VB said:

I'm not at all an expert but i happen to have some poeci's and a couple of them are paired females. 3 of them did web for having an egg sac i think. 2 of those have an hollow cork tube an the other just some cork against the glass and that one webbed like crazy.

Here some pics :

P. miranda in tube (which i think has an egg sac atm):
P. regalis also in tube without an egg sac :
And the P. subfusca without a tube, which had a sac but i don't see it anymore All 3 stay in there from the moment they 'closed' it but the P. subfusca came out yesterday late at night, so that's why i went checking and didn't spot the egg sac anymore...

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All of those look like egg sac-related spinning. My Miranda's look like that, completely sealed behind several layers of silk. Hard to see inside, even with a flashlight. If the subfusca's out and doesn't carry her sac, you can scratch that one, she either ate it or discarded it. Hopefully the other two will go full-term. My miranda this year are the first time I've seen a Poec stay in the chamber like that.

Ive had regalis, fasciata, and vittata do this as well.

David VB said:

I'm not at all an expert but i happen to have some poeci's and a couple of them are paired females. 3 of them did web for having an egg sac i think. 2 of those have an hollow cork tube an the other just some cork against the glass and that one webbed like crazy.

Here some pics :

P. miranda in tube (which i think has an egg sac atm):

P. regalis also in tube without an egg sac :

And the P. subfusca without a tube, which had a sac but i don't see it anymore :

All 3 stay in there from the moment they 'closed' it but the P. subfusca came out yesterday late at night, so that's why i went checking and didn't spot the egg sac anymore...

Click to expand...

That looks like there can be succes. They either give you the desired sac, or they molt. The subfusca you can forget about, if you dont see it, she ate it. All my paired miranda made this webbing and i am happy they did i can say.

Poec54 said:

I currently have 6 Poecilotheria females sitting on sacs: 2 fascata, 2 regalis, and 2 tigrina. In the last year I've hatched out 2 regalis and 1 ornata sacs. In all of this activity, the norm is for the females to make a silk chamber under a cork slab, spin a thick mat on the bottom, lay her eggs on that, then roll up the silk and eggs into a ball. They tear down the silk chamber and can come out if they want (maybe for an occasional drink or snack). But not the tigrinas. Both females are still sealed in their silk chambers a couple weeks later.

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FYI: My P. regalis did everything you explain above and is still in her silk chamber after 2 weeks. If you pull their water dish how do they get water? Do you keep the substrate moist or dry? Thanks!!

---------- Post added 04-17-2014 at 09:30 PM ----------

Ceratogyrus said:

I have also had regalis seal themselves in. Pretty sure my rufilata did the same.
Can't remember seeing the others sealing themselves in for the full incubation (I let the females hatch their own sacs)

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How did that go for you? Have you had some of your pokies eat their sacs?

MrCrackerpants said:

FYI: My P. regalis did everything you explain above and is still in her silk chamber after 2 weeks. If you pull their water dish how do they get water? Do you keep the substrate moist or dry? Thanks!!

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I pull the bowls on everyone now, except the ones with hammock sacs. I'll sprinkle a little water on the substrate once in a while when it gets dry, but I don't overdo it, as I don't want mites getting on/in the sac. I also pulled the waterbowls from the sealed-in tigrinas, they're not coming out to drink anyways. After you've had a sac drowned, you won't hesitate to take away water bowl prividges too.

Poec54 said:

I pull the bowls on everyone now, except the ones with hammock sacs. I'll sprinkle a little water on the substrate once in a while when it gets dry, but I don't overdo it, as I don't want mites getting on/in the sac. I also pulled the waterbowls from the sealed-in tigrinas, they're not coming out to drink anyways. After you've had a sac drowned, you won't hesitate to take away water bowl prividges too.

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Thanks! So just to clarify a P. regalis with a sac would be fine without a water bowl? I know the semi-moist substrate will reduce her water loss but she will not be able to drink from the substrate. Just making sure!

MrCrackerpants said:

Thanks! So just to clarify a P. regalis with a sac would be fine without a water bowl? I know the semi-moist substrate will reduce her water loss but she will not be able to drink from the substrate. Just making sure!

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Correct. Most females don't eat or drink when they're holding a sac (not that I've seen anyways). They're very devoted mothers. I'll moisten the substrate to raise the humidity a bit (but you can overdo it), which in turn reduces her water loss over that period. Plus many of us pull sacs at around 30 days, so it's that as much of an ordeal for them. As soon as I pull a sac, I give the female a water bowl again, and within a day or two start offering her food. The goal being to get the weight back on her so she can go back to normal.

Poec54 said:

Correct. Most females don't eat or drink when they're holding a sac (not that I've seen anyways). They're very devoted mothers. I'll moisten the substrate to raise the humidity a bit (but you can overdo it), which in turn reduces her water loss over that period. Plus many of us pull sacs at around 30 days, so it's that as much of an ordeal for them. As soon as I pull a sac, I give the female a water bowl again, and within a day or two start offering her food. The goal being to get the weight back on her so she can go back to normal.

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Thanks for the clarification

MrCrackerpants said:

How did that go for you? Have you had some of your pokies eat their sacs?

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Yes, had a few eating their sacs, but I would guess less than 10%.

All arboreals can do just fine without waterbowls, i only give avics waterbowls as it helps increase the humidity and i can keep the substrate less wet. Only for periods in breeding when i need to dry out the enclosure i introduce waterbowls. Otherwise i just use misting to keep them happy. I have only once in my many years in this hobby seen an arboreal use waterbowls, the tend to try and suck from the substrate. I add a waterbowl for a period if i see that.
When they have sacs i just water the corners away from the sac to keep humidity up.

Can i pull an egg sac too soon and what happens then? I'm not sure when or even if there is one but if i tear down their webs to check or pull the sac, they're being disturbed and that's not what i want... Is it a good idea to count 5 or 6 weeks from the day they were fully webbed in to check and maybe pull the egg sac if there is one?