In response to the current debate concerning humidity...

[Paul Day]

I'm sorry, I misinterpreted you Scott about the spiderlings needing water dishes... I think a lot can be learned here about humidity levels. I think Scott has brought up a good question here:

"I think T's need internal hydration more than anything else to succesfully molt. This would mean that having a source of water for the T to drink whenever it would need to is more important than air humidity. "

When spiders eat food, they suck on it, sucking the moisture out of it. That is what makes their little bodies fat, and what is that "fat"? It's mostly moisture! That is how you can tell if a spider is dehydrated or not, if it's body is plump and healthy looking. In this case, if I was to apply my theory to yours about enviormental humidity not being important Scott, I could technically take the water dish out of a T. blondi's aquarium, stop misting the aquarium, and the spider would be ok as long as I fed it an enormous amount of food all the time! But would this be healthy? Anyone want to test my theory (hehe). In fact, crickets themselves are very moist! Have you ever squeezed one (I'm sure you have). It's very easy to believe that they are mostly water, like tarantulas, like HUMANS (but we need direct sources moisture for different reasons)!

There is an increasing suspicion that molting problems have little to do with inadequate humidity levels. I think Sam Marshall's book describes this (I could be mistaken... maybe it was Schultz). As tarantulas are mostly water by weight (something like 99%), this rarely becomes a problem unless the spider is on the verge of death and has been kept at a improper humidity level for a long time. That is especally difficult to theorize if if the spider is fat . So if anything, a spider fails a molt due to not being fed enough!

Never let your spider starve or get skinny prior to premolt. This means, when you expect it to happen, increase feedings! This will help build up the moisture in the spiders body! This is my theory. I could be wrong, but has totally worked for me in telling if I'm doing "ok".

Have you ever noticed how a tarantulas body decreases in plumpness after a molt? This is because the spider loses an excessive amount of moisture after the event (in fact, you can see the moisture on the skin of the spider). If a spider dies a few days after a molt, it most likely is because the humidity in the environment was not being properly maintained during post molt. So in that case, humidity is a concern, since the spider has not eaten at the time (being in postmolt). But water dishes can help at this point, but you can also do it by misting. It's a matter of preference really.

I really don't think we are all too sure why tarantulas fail molts, we just assume it's humidity. In some instances, such as a real old tarantula not being able to pull out of the skin, it makes sense, but rarely (unless a tarantula is skinny and dehydrated to begin with) could that be a proven answer to a problem. Tarantulas kept at seemingly perfect humidity levels can fail at molting (and often do in the case of T. blondi, with little other possible cause). So I do not see the proof nor the correlation in the prognosis that humidity is the primary blame for molting problems.

So, in conclusion, humidity, maintained by anything but food, is only a true concern during premolt or postmolt, when the spider is not eating or absorbing moisture through food anymore. The humidity in the air prevents the spider from "drying out", so there is no need to use a water dish in most spiders enclosures. So if the spider has stopped eating, increase humidity levels immediately to prevent complications.

I could be wrong, again, but it makes sense to me.
Anyone else have anything else to add?
Pauly

 

[ArachnoJoost]

"So if anything, a spider fails a molt due to not being fed enough!"

I thought a spider could 'choose' the moment he goes into premolt, and not have a set time for it. Because with powerfeeding there is less time between molts. I cannot believe that a spider that is too skinny would go into premolt, in the wild a spider can't feed as regularly as we give them food, so I think they would only go in premolt if they had a few good meals (especially for the adults).
And I think most people do feed their spiders enough, so there must be some other reason for the failed molts.
Another idea is that in the wild only a small number of spiderlings survive to be spiders, only the strongest. In the hobby you try to keep every spiderling alive, so the 'weak' ones survive as well, this can cause weak bloodlines if they are bred with. So on the long run, you can expect some problems with spiders, and because molting is the most critical time, you'd notice it there first
btw, that doesn't mean I know the solution for this, I would probably try to save as much also.
just a thought,
greetz,
Joost

 

[Botar]

Joost,

I've never heard that the T can choose when it goes into premolt. I'm not saying that isn't the case, just that I've never heard of it. Do you know where you read that? I would like to read more on it.

Botar

 

[ithuriel]

personnaly i provide my Ts with wide shallow water dishes with cotton wool to stop accidents. my b.vagans has a habit of when she is eating a cricket of sitting on her dish and occasionally having a drink. one time a cricket did something to her and she threw a wobbly , legs going everywhere throwing her body up and down and she dashed straight for the dish , sat on it and after a few minutes was ok , went back and ate the cricket. she is quite happy , fat and is so secure in her cage now she doesnt sit in her burrow anymore . very pretty too , really gotta get my digital camera back.my rosie likes her dish too but is more restrained and uses it more has a cricket trap i also quite regularly change/clean the dishes(good way to keep an eye out for mites too). .......oh , just in case you might think rusty sits on her dish while she is eating because the humidity is low , isnt the case, she just has got into the habit of doing it , strange quirky little T:?

 

[ArachnoJoost]

Botar:
Didn't read it anywhere, it was a thought of mine, and I do not quite mean 'choose' as if a spider thinks about that...
It's just that when you powerfeed a T it will molt and grow faster, so I thought that could/would work the other way around, that the spider 'delays' his molt till he has had enough to eat and can make it safely through the molt.
greetz,
Joost

 

[schlinkey]

sounds logical Joost..

 

[MrDeranged]

I see what you're saying Joost, but I think that 'delay' is the wrong word for it. IMO, it's not a conscious decision on the part of the T, but more it's body's response to not having the needed resources to complete the molt. In powerfed spiderlings, they're getting much more food than is necessary, thereby keeping their reserves at a level that is conducive to molting more often. Reserve levels are not the only thing to consider either. When dealing with larger T's, you can powerfeed as much as you want, you're still not going to get them to molt every three weeks. There is a time period that HAS to pass, whether in slings or adults, for the new exuvia to be formed. As slings are smaller, and with the powerfeeding, have a larger resource store in comparison to their size, they MAY be able to complete this quicker than a larger adult that is being comparatively fed. Irregardless of this, a T has a set time period, although no one knows what this may be, and whether or not they have the resources available, they will molt when that new exoskeleton is ready. If they don't, they're gonna die.

Hope that doesn't add more questions to the pot

Scott

 

[MrDeranged]

"I'm sorry, I misinterpreted you Scott about the spiderlings needing water dishes"

Not a problem, it happens.

"When spiders eat food, they suck on it, sucking the moisture out of it."

IMO, not really. What they're doing is liquifying solid body mass and then ingesting that. I guess the easiest way to compare it is to picture being fed through an IV.

"In this case, if I was to apply my theory to yours about enviormental humidity not being important"

I never said that environmental humidity is not important, just that it is not AS important as internal hydration.

"I could technically take the water dish out of a T. blondi's aquarium, stop misting the aquarium, and the spider would be ok as long as I fed it an enormous amount of food all the time! But would this be healthy?"

Technically you should be able to if my theory is fact. When dealing with T's that come from extremely humid environments, there are too many other variables as well though. Did they evovle to utilize the high humidity of their environment. Is there something about the moisture levels of their environment that is conducive to their molting properly? Is there something about their size that prohibits them storing enough resources for them to successfully molt in an arid environment? These are just a few of the questions that come to mind when dealing with any High Humidity environment species.

"If a spider dies a few days after a molt, it most likely is because the humidity in the environment was not being properly maintained during post molt. So in that case, humidity is a concern, since the spider has not eaten at the time (being in postmolt). "

This is definitely a possibility, but there is also the fact that it may be a problem with something internal that we have no idea about.

"so there is no need to use a water dish in most spiders enclosures."

I wouldn't necessarily say that. Although technically, it should work as long as there is enough prey for the T to get it's needed resources, I feel that there should be a water dish in all T's enclosures on the chance that at some time, it may need to regulate by getting a drink.

Scott

 

[belewfripp]

Safety Net

I basically think of water dishes as safety nets. If I knew exactly what the current biological condition of the T was, what the effects a certain amount of moisture would concretely have on that biological condition, and had the knowledge and information to regulate precisely according to necessity, I could probably do without a dish. Mostly, though, we don't have that kind of precision available. We can make more broad, generalised statements about what is going on but not a whole lot more.


While I maintain a few Ts without water dishes (1 1/2 in. H. minax, 3 in. T. blondi, 2 in. C. brachycephalus, 1 1/2 in. A. moderatum) that has more to do with the container not being big enoough. I have a 1 in. Grammostola sp. "Chaco golden-knee" that has molted perfectly under utterly bone-dry circumstances. And for the more moisture-dependant ones, I keep the substrate pretty well-watered. For the T. blondi, no water dish is used because whenever it has been thirsty I have observed it simply hunkering down to the wet substrate and sucking water from it.


For the most part though I consider my information on what state they currently are in and what they need to be imperfect and incomplete. With a water dish, you have a safety net. The ambient humidity might drop a little too low for a few days before you notice or feeding time comes up again but if there is a full water dish the T can sustain itself and minimise moisture loss by drinking from the dish when it needs to. In this way I feel more comfortable using a dish.


While I might be able to get away with not using one in most of my T's tanks, I prefer to have it there in case I screw up or something comes up and I can't get to spider maintanance until later. At times I have had to put off feeding/watering for as long as an extra week, making two weeks since some of them have had substrate moistening and feeding. With a water dish, in situations like these the likelihood of having a dead or severely dehydrated T are lessened. due to the presence of several large aquariums in the spider room the ambient humidity is high enough that water dish evaporation is not very high and usually enough water remains in the dish even over that length of time that the T can get some kind of moisture boost if I'm running behind in my care.


Adrian

 

[Paul Day]

" personnaly i provide my Ts with wide shallow water dishes with cotton wool to stop accidents."

While you are stopping one accident, you are creating another bad situation. It's been said by Schultz that there might be some correlation between sponges or cotton in water dishs and dying tarantulas. This is because any cloth or deeply pourous material placed in standing water becomes a breeding ground for bacteria. These are difficult to clean as well, without possibly running them through a washer (but of course, soap and bleach won't be good for the spider either. Spiders can not tell clean water from dirty water I'm afraid.


"I basically think of water dishes as safety nets. If I knew exactly what the current biological condition of the T was, what the effects a certain amount of moisture would concretely have on that biological condition, and had the knowledge and information to regulate precisely according to necessity, I could probably do without a dish."

Of course, there is nothing wrong with overcompensation. I don't personally feel confident enough to try raising a huge Blondi without a water dish, but I am comfortable enough to do it with a lot of other species. It's really a matter of preference.


"IMO, not really. What they're doing is liquifying solid body mass and then ingesting that. I guess the easiest way to compare it is to picture being fed through an IV."

Yeah, I should of put that differently Scott, but it doesn't change that spiders are absorbing moisture through their food. It is mostly water, with some proteins and ash.


"When dealing with T's that come from extremely humid environments, there are too many other variables as well though. "

Of course! And this is why everything is theory. There is so little known about a T. blondi's habits in the wild. Shoot, we are just now discovering the exact habits of black bears during hybernation, and we are learning that they are doing a lot more then just "sleeping".


"I thought a spider could 'choose' the moment he goes into premolt, and not have a set time for it"

As for spiders being able to "control" molting, I believe it's sort of like going to the bathroom. Like they need to do it, but can put it off slightly. But they don't actually "choose" to. And molting isn't a "timed" event. It depends on a lot of different factors, primarly the temp. in the enclosure. If it's higher, the spider will molt faster. But power feeding the spider more also contributes, but to what degree I could not tell you...


"my b.vagans has a habit of when she is eating a cricket of sitting on her dish and occasionally having a drink."

Contrary to popular belief, B. vagans is NOT a dryland species. It is one of the exceptions in Brachypelma, along with the curlyhair. You should be keeping it at medium humidity, and it'll do fine without a water dish (I'm assuming you are keeping it dry, and forgive me if I'm mistaken). Chaco's are not dryland species either. The Chilean Rose is the exception in Grammastola, as most other species in that genus require medium humidity. But I'm sure they can stand low humidity too for a while if you provide a water dish, I'd just rather mist.

"It's just that when you powerfeed a T it will molt and grow faster"

I do not think powerfeeding has a signifigant effect on molting intervals. For instance, I had a A. chalcodes go into molt 5 months ahead of schedule for no appearent reason, besides a drastic change in temp (increase). I fed it normal amounts of food . So I think temp is what you should concern yourself about if you want your spider to grow fast. But feeding a lot of food to a spider ensures max. size, and a reserve of moisture.


"I have observed it simply hunkering down to the wet substrate and sucking water from it."

Simply put, especially with spiderlings, the water droplets that fall into the soil are enough to keep a spider at bay if it needs a quick fix when it's thirsty, IMO. So this is proof enough that spiders do not "need" a water dish. I don't keep a water dish with my 4 inch Blondi either, but don't tell anyone (though I constantly keep the substrate watered). It would bury it, so I had no choice

Pauly