Is it true that Lasiodora parahybana doesnt stop growing?

[Tobey]

Hi! I just got my first L. Parahybana. Its an adult female (from what the breeder told me). I have heard this species of T. never stops growing, is this true? If not, when do they actually stop growing?

 

[Ran]

I believe all female tarantula species grow till they die.

 

[Nightstalker47]

Hi! I just got my first L. Parahybana. Its an adult female (from what the breeder told me). I have heard this species of T. never stops growing, is this true? If not, when do they actually stop growing?

Only males stop growing, and that's when they mature. Some will attempt to molt again after maturity but they almost all universally die in the process.

Every female tarantula regardless of species will molt and grow until its death. The growth will slow down drastically as the spider ages, but it will not cease.

 

[EulersK]

... no.

Female tarantulas never stop molting, until death of course. But they most certainly do stop growing. Some species of tarantula live for decades - it's not like they grow perpetually until they die like a tree.

Very basic biology is at play here, namely genetics. But even beyond that there is the issue of respiration. Remember learning about the giant bugs back in prehistoric times? That was because the oxygen levels in the air were much higher. There's a reason those bugs don't exist anymore - their bodies simply can't transport the oxygen effectively enough to support a large body. So there is a maximum size that spiders can grow both genetically and physically.

The likes of Lasiodora and Theraphosa seem to show us the maximum body mass that a tarantula's circulatory system can handle: around 8"-10" and a third of a pound. Much larger and they'd likely suffocate.

 

[Tobey]

Gotcha, thank you for the info!

 

[cold blood]

... no.

Female tarantulas never stop molting, until death of course. But they most certainly do stop growing. Some species of tarantula live for decades - it's not like they grow perpetually until they die like a tree.

Very basic biology is at play here, namely genetics. But even beyond that there is the issue of respiration. Remember learning about the giant bugs back in prehistoric times? That was because the oxygen levels in the air were much higher. There's a reason those bugs don't exist anymore - their bodies simply can't transport the oxygen effectively enough to support a large body. So there is a maximum size that spiders can grow both genetically and physically.

The likes of Lasiodora and Theraphosa seem to show us the maximum body mass that a tarantula's circulatory system can handle: around 8"-10" and a third of a pound. Much larger and they'd likely suffocate.

Agreed....but a LP is a 7-8 inch range t....not 8-10" as the LP hype train would like you to believe....lots of exaggerrated hype out there in an attempt to move value-less LPs.

 

[darkness975]

I have heard this species of T. never stops growing, is this true?

Sounds like sensationalism with the intention to sell more LP's. They will max out eventually as previously stated.

 

[boina]

Theoretically a tarantula can grow with every molt - if the conditions are favorably and it has lots of food. However, that doesn't mean if you feed a tarantula enough it will get huge. After maturity growth will slow down considerably, so they may still grow with every molt, but something in the range of a few mm - that's like 1/8th to 1/16th of an inch, so not something you'd really notice. Very old tarantulas will often be bigger than average for the species, but since growth slows down so much you will not get oversized tarantulas.

 

[darkness975]

Theoretically a tarantula can grow with every molt - if the conditions are favorably and it has lots of food. However, that doesn't mean if you feed a tarantula enough it will get huge. After maturity growth will slow down considerably, so they may still grow with every molt, but something in the range of a few mm - that's like 1/8th to 1/16th of an inch, so not something you'd really notice. Very old tarantulas will often be bigger than average for the species, but since growth slows down so much you will not get oversized tarantulas.

You mean that episode of Monster Quest I saw where there is a giant 4 foot long Tarantula large enough to eat humans is not real??? I was looking forward to adding one of those to my collection!

 

[RemyZee]

Agreed....but a LP is a 7-8 inch range t....not 8-10" as the LP hype train would like you to believe....lots of exaggerrated hype out there in an attempt to move value-less LPs.

I wouldn't call them "value-less". They are nice looking spiders, and I quite enjoy them.

 

[EulersK]

Agreed....but a LP is a 7-8 inch range t....not 8-10" as the LP hype train would like you to believe....lots of exaggerrated hype out there in an attempt to move value-less LPs.

Agreed, but someone always raised their hand with "I've got a nine-incher!" Just trying to avoid that.

 

[Nightstalker47]

... no.

Female tarantulas never stop molting, until death of course. But they most certainly do stop growing.

I'm not convinced that growth would come to a complete hault. In order for Ecdysis to take place the arthropod has to have outgrown it's former exoskeleton, if not the process is impossible. So technically, molting in itself will always result in growth, be it minimal or not.

The very definition of "molt" is to shed and cast away a former shell/skin/exo to make way for growth. You can't have one without the other, it's true that with older specimens it may be less noticeable, but that doesn't necessarily mean it's not happening.

 

[EulersK]

The very definition of "molt" is to shed and cast away a former shell/skin/exo to make way for growth. You can't have one without the other, it's true that with older specimens it may be less noticeable, but that doesn't necessarily mean it's not happening.

Not sure how true this bit is. I've personally witnessed many males that are actually smaller after molting. I don't mean skinnier - I mean that their literal diagonal leg span is less, they have a smaller carapace, and their abdomen is smaller. I first saw this in E. truculentus, where the spider ended up being almost an inch smaller after maturing into a male.

And even if the growth is necessary, we all have adult females that have molted and put on no noticable size, even fractions of an inch. If it's not noticable to even a ruler, then even if they're indeed growing by a miniscule amount it doesn't matter. If you tell someone that they grow indefinitely until death, images of a giant old tarantula come to mind. Which is misleading to say the least.

 

[RemyZee]

Agreed, but someone always raised their hand with "I've got a nine-incher!" Just trying to avoid that.

Lol! True dat.

 

[Tomoran]

You mean that episode of Monster Quest I saw where there is a giant 4 foot long Tarantula large enough to eat humans is not real??? I was looking forward to adding one of those to my collection!

I literally JUST watched that one again last night! hahaha

 

[cold blood]

I'm not convinced that growth would come to a complete hault.

My G. porteri has the exact measurements that she did 20 years ago...she's molted like 6 times in that span.

They never stop molting...but growth does halt or we would see that old individuals of longer lived species would be consistently very large...they are not. Even the longest lived species have a max size they reach. Genetics + environment should give individual growth an ultimate limit.

In order for Ecdysis to take place the arthropod has to have outgrown it's former exoskeleton

Then explain my porteri.

Growth is almost certainly not the lone trigger, just the most obvious.

The very definition of "molt" is to shed and cast away a former shell/skin/exo to make way for growth

The very definition may need revision then...hehe.....wouldn't be the first time.

 

[cold blood]

I literally JUST watched that one again last night! hahaha

So disappointing, wasn't it.

But I think we all knew what to expect...the whole time they were talking about it, I was like,

 

[Tomoran]

It sure was! I had seen it years ago, but I didn't remember how truly awful it was. My favorite part is by far when Rick West tries to keep a straight face as the shaman describes the giant person-snatching spider! Haha

So disappointing, wasn't it.
But I think we all knew what to expect...the whole time they were talking about it, I was like,

 

[AphonopelmaTX]

I'm not convinced that growth would come to a complete hault. In order for Ecdysis to take place the arthropod has to have outgrown it's former exoskeleton, if not the process is impossible. So technically, molting in itself will always result in growth, be it minimal or not.

The very definition of "molt" is to shed and cast away a former shell/skin/exo to make way for growth. You can't have one without the other, it's true that with older specimens it may be less noticeable, but that doesn't necessarily mean it's not happening.

That's not necessarily true, but I would like to know what your thought process is though. Ecdysis is just one step in several which an arthropod goes through to replenish the cuticular layers that make up the exo and endo skeletons as well as other parts of the anatomy. Ecdysis is the process you actually see, in other words, when a spider is coming out of the old "skin." Molting and ecdysis are synonymous.

One step you don't see is the regrowth of the new cuticle layers underneath the old. That new cuticle doesn't have to be larger than the old cuticle for successful completion of ecdysis. That new cuticle is soft and pliable and for a spider to pop open the carapace, it forces hemolymph to the prosoma essentially inflating itself. For spiders that undergo regular postultimate molts, like female tarantulas, the spider's body is very slowly replacing the parts it can but not growing in size. Think of it in a similar way to how we humans are constantly growing new skin cells and shedding off old, dead skin cells. A spider which undergoes regular postultimate molts essentially does the same thing but at a much slower pace. Something like once a year for adult female tarantulas.

 

[cold blood]

Think of it in a similar way to how we humans are constantly growing new skin cells and shedding off old, dead skin cells. A spider which undergoes regular postultimate molts essentially does the same thing but at a much slower pace. Something like once a year for adult female tarantulas.

I literally almost used this same comparison.