B. smithi / B. emilia

fuzzytarantula

Arachnopeon
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Sep 9, 2011
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Hello everyone,

I was wondering how long it would take for a female B. smithi or B. emilia to grow 2 - 3 - 4 inches? [An answer for all three, please :)] I'm trying to get a female specifically; am I correct that they generally get bigger than males? Is there a general lifespan chart that shows their gender, age & corresponding size?

Thanks for everyone's help!

Rissa
 

xhexdx

ArachnoGod
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Jul 20, 2007
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It depends on how much you are feeding them and what temps they are kept at. The more you feed and the higher the temps (within reason - I wouldn't stray higher than 85 degrees), the faster they grow.

Females are generally bulkier than mature males.

I'm not aware of any charts of that nature.

Pics of my emilia:



 
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fuzzytarantula

Arachnopeon
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Beautiful emilia! I'm leaning more towards them than the smithi kind I think.

Still, does anyone have a rough idea how old a 2" female might be?
 

jbm150

Arachnoprince
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I've grown up two emilia slings from specks to 2.5", both only took a few months (probably 6 at the most). I can check my molt records when I get home for accuracy. Both however were male, so take from that what you will. I will say, they far exceeded the pace of my pulchra; it's been almost 2 years and she's barely past 2" :/
 

JC

Arachnolort
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I managed to get a .75" B.smithi female up to the 3" mark in about four month time. And a 1" B.emilia sling took me 7 months to get it to 3", I fed B.emilia alot less and the temperature was alot lower.
 

Status

Arachnopeon
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Sep 11, 2011
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sorry for being an idiot, but is the B. emilia the mexican painted red leg? (i'm not good with the names yet :( )
 

fuzzytarantula

Arachnopeon
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Sep 9, 2011
Messages
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Thank you Jeff & JC! :) I was thinking about buying a 3" and wanted to get a rough idea how old she is.

My next question is, are you able to determine the sex of a 3" tarantula? What differences should I look for in a female?
 

jbm150

Arachnoprince
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It's still tough to really say for a 3" specimen. Joe's probably pretty close, I'd say 1-3 yr old would cover the majority (there are probably outlyers on both sides). I'm not sure how much difference you'd see physically at that small size. You'd have to look ventrally (plenty of threads on how to do that) or best case, look at a molt. As they get bigger, females tend to get "thicker" than their male counterparts
 

cnapple

Arachnoknight
Joined
May 23, 2011
Messages
152
Thank you Jeff & JC! :) I was thinking about buying a 3" and wanted to get a rough idea how old she is.

My next question is, are you able to determine the sex of a 3" tarantula? What differences should I look for in a female?
I was able to sex, both ventrally (estimate) and via spermathecae, my 3.5" B. auratum, so you shoild be able to. There are some excellent sticky threads for learning how to sex. I'd link for you but i'm on a nook e reader now and it's hard enough to type! ;)
 

xhexdx

ArachnoGod
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JC

Arachnolort
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I disagree.

Your link is to a 2" spider, first of all. Second, a .5" spider isn't going to have any of its sex organs developed to the point of being viewable, even under a microscope. I would be very interested to see something that proves otherwise.
Have you tried looking for it under a microscope?

Yeah, my bad. Was just looking for an example of a scoped image to show cnapple. Not the best example for a .5", but it should help with cnapple's 3" spider.
 
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JC

Arachnolort
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Ok, this is where I am getting to if you haven't already noticed, and where I believe most of your confusion lies

The following statement is simply incorrect:


Second, a .5" spider isn't going to have any of its sex organs developed to the point of being viewable, even under a microscope.


So is this statement(close but not scientifically correct):


Go by size, not by age. Age means nothing regarding maturity.


Because as I explained here:

http://www.arachnoboards.com/ab/sho...ro-Venezuela&p=1834782&viewfull=1#post1834782

Not size, but anatomical structure.
In order for an animal to be considered sexually matured, it needs to have fully developed its sexual organs. End of story.

For example, when we see a Poecilotheria ornata in the FS section marketed at 7'', we assume that it is fully sexually matured only because it is at this size they are normally matured. Truthfully size means nothing, because it is the physical development of the spermathacae that determines this in conjunction with the functioning of the spiders other sexual organs. You may also have the reverse situation. You may have a Chromatopelma cyaneopubescens mature at 2.5 inches, because the sexual organs are ready and able to produce offspring. Scientific biological anomalies yes, but if you understand the basics they are very possible.

In a nutshell:

Functioning sex organs and offsprings can be produced = sexually mature
Not yet possible to produce offspring = immature

Now you are asking if size makes a difference if how much offspring can be produced. The answer is yes, but it has to do with the animal's prime states, different story.

So, before I rap up on this thread, let me clear some things up.

1. YES, I have sexed 0.5'' slings accurately through a scope. They were very slow growing species, such as B.klaasi and desert Aphonopelma sp.. These spiders where maybe .33'' when I received them, and three to four molts later finally reached .5''(maybe even shrank on one particular molt). This would have given sufficient time for some type of sexual organ development.

2. Most of our hobbyists aren't that well equipped when it comes to acquiring data on tarantulas on a microscopic level(not saying you in particular). I am pretty sure someone with a grade 'A' stereoscopic microscope and a understanding of lighting can easily find sex organs on a .5'' sling on large number of species.
 
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Amoeba

Arachnolord
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Jun 13, 2011
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603
Read what JC and xhexdx have written then apply what you've learned to your question. Also apply that Ken the bug guy is a dealer and has done this for a bit.
 

xhexdx

ArachnoGod
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I suppose, first of all, that any .5" sling (with the exception of Cyriocosmus spp. and maybe a couple others) is going to be second or third instar. Yes, the higher the instar, the more developed the spider will be. So I suppose I made an assumption and should have been more specific. My apologies. That being said:

So, before I rap up on this thread, let me clear some things up.

1. YES, I have sexed 0.5'' slings accurately through a scope. They were very slow growing species, such as B.klaasi and desert Aphonopelma sp.. These spiders where maybe .33'' when I received them, and three to four molts later finally reached .5''(maybe even shrank on one particular molt). This would have given sufficient time for some type of sexual organ development.
Three or four molts to go from a third of an inch to half an inch? Over what timeframe? Even Brachypelma and Aphonopelma are going to show more growth than that - I have also never (in my experience) seen a spider lose size after a molt. What exactly is 'sufficient time of sexual organ development'?

2. Most of our hobbyists aren't that well equipped when it comes to acquiring data on tarantulas on a microscopic level(not saying you in particular). I am pretty sure someone with a grade 'A' stereoscopic microscope and a understanding of lighting can easily find sex organs on a .5'' sling on large number of species.
I am pretty sure someone with such a setup and understanding would also be taking pictures of these .5" molts that clearly show spermathecae, yes?

One last thing to try and clarify...I acknowledge that as the spider molts and grows, so do the sex organs, etc. I suppose if someone has the perfect setup and knows exactly what to look for regarding the beginnings of sex organs, that it would be possible.

I'd still like to see pictures.
 
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