Spider's age and sex?

SueinTX

Arachnopeon
Joined
Dec 16, 2002
Messages
8
If I call my spider a "Smithi", that's the same as calling him a Mexican Red Knee, right? I'm brand new to this, so forgive me....and I truly do want to learn. :?

They said they don't know how old the spider is, but that they get them when they're young and he just went through his first molt. It was a Petco store, so should I assume they know for sure he/she is a real youngster? Is there any other way to tell besides the size? Last night when I looked at him really closely, from one tip of his foot, across horizontally to the other tip of his other foot is really about three inches.

About the sex, I have to wait until it's mature, but then what do I look for?

Also, I noticed that he created a small "web" from the edge of his water dish (it's a flatter ceramic dish a little more narrow than he is and it has stones in it that I put to keep him or the crickets from drowning) about a few inches down into his substrate. Is this okay? Does it mean anything?

Thanks again for all your help. I am finding all of this so fascinating. He seems to be a pretty mellow spider. When I put my hand in to change the water or put the temperature/humidity gauge in or put in a new thing for him to hide under, he could care less. And when I was holding him at the store, with some gentle nudging, he just climbed onto my hand and then my other hand and never flicked hairs. The pet store guy told me nothing about washing my hands after handling my spider because of the hairs!! Thanks for that advice ya'all. Have a good day.
 

Mojo Jojo

Arachnoking
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Nov 3, 2002
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It would be perfectly fine to refer to your red knee as a smithi (unless of course it isn't).

When they say it was his first molt, they mean since they acquired him. Believe me, there have been many prior molts. I have a link to another site, where you can see a cuouple of pictures of a red knee spiderling.

http://www.bighairyspiders.com/pic_smithi.shtml

Both pics are of the same t. The first one is probably after 1st molt. The second, I am guessing, is 1 molt later. Now these shots are closeups, with nothing for size comparison. But it is a really good website, so be sure to find the homepage and to bookmark it.

I am also posting a picture of my Brachypelma angustum. You have (think you have) a Brachypelma smithi. So they are closely reIated.

I just got done taking the picture. This guy has gone through one molt since I had it. That was probably its 2nd or 3rd molt.
I have put it by a penny, for you to use to compare size. (This guy is REAL fat!

Oh yeah, maybe somebody could post pics of their juvi smithis and juvi rosies.
 
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Code Monkey

Arachnoemperor
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Jul 22, 2002
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Originally posted by SueinTX
If I call my spider a "Smithi", that's the same as calling him a Mexican Red Knee, right?
Yes, smithi is a common shorthand for Mexican Redknee or Brachypelma smithi. As a rule, we generally refer to all Ts with their scientific name unless they're really common. This prevents any confusion about what is being talked about.

They said they don't know how old the spider is, but that they get them when they're young and he just went through his first molt. It was a Petco store, so should I assume they know for sure he/she is a real youngster?
Unless you're lucky enough to have a Petco where the invert/herp guy is a hobbyist *on his own*, I wouldn't trust them to tell me how many legs they have. That said, odds are any smithis they have will be young because with few exceptions for smuggled specimens, all smithi sold within the U.S. are captive bred and there's no profit in waiting around for larger than large enough that it looks like a B. smithi. An adult is about 5" or so in legspan and they grow relatively slowly so you should be able to tell if it's young or nearing maturity by size. Since you say he's about 3" it's probably somewhere in the range of 2.5 to 3 years in age.

About the sex, I have to wait until it's mature, but then what do I look for?
Actually, at 3" you can easily sex a T just by examining the epigastric furrow between the anterior book lungs. I find that Brachypelma individuals can be sexed very reliably at any size around 2" or above. Check out this recent thread for some photos:http://www.arachnopets.com/arachnoboards/showthread.php?s=&threadid=3451. This has also led some to suspect that the dealers selling to Petco and similar stores are dumping their male off. If you do have a male, it will probably mature within the next 2 years if it's already 3". If you lucked out and got a girl, you've got at least 15 to 20 years more with her.

Also, I noticed that he created a small "web" from the edge of his water dish (it's a flatter ceramic dish a little more narrow than he is and it has stones in it that I put to keep him or the crickets from drowning) about a few inches down into his substrate. Is this okay? Does it mean anything?
It means it's a tarantula. Whether you can see it or not, your T will cover everything in its tank with webbing. This probably makes it easier for it to get around and to sense prey.
 

Lasiodora

Arachnoangel
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Oct 11, 2002
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852
Brachypelma smithi is the scientific name for mexican redknee. Scientific names are more accurate because sometimes the same spider has more than one common name. This confuses things and many times leads to misidentifying the spider. Three inches would be considered juvenile. There is no way to get an exact age without having molting records from when it was a sling to now. Well at this size I believe you can sex him/her. You can wait for it to shed then look for the spermatheca a pic is in this thread by Lariz:
http://www.arachnopets.com/arachnoboards/showthread.php?s=&threadid=3733

The spermatheca is located between the book lungs in the picture. The book lungs are the four white objects.

You can also visually sex an adukt mature spider. Males have palpal bulbs on their pedipalps. You can't miss it. It makes their pedipalps look swollen. They will also have spurs on their pair of first legs.

The web laying is normal. That just means it's settling in. When it lays down a heavy web it is getting ready to molt. Yours already did that. So it will be awile before it does again.
Mike
 

rknralf

Arachnolord
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Jul 19, 2002
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Is this what yours looks like?

Here is a picture of my male B. smithi.
I got him in April and he was about 2 inches. He is now about 3.5 inches and is getting ready for a molt. Since I got him he has molted 3 times and this next one will be his 4th with me.
All in all, he has a bad attitude and is not handleable. He flicks hair and will strike if not left alone. This behavior only started after he reached this size.
I hope yours stays friendly.
Ralph
 

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SueinTX

Arachnopeon
Joined
Dec 16, 2002
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8
Ralph,

My spider looks just like yours except the red on his knees is brighter. Not saying anything about your spider not being pretty, because it certainly is, just saying that to give you more information about him. Like if a brighter or deeper red means it's older. Although I am new to T's, my spider is definitely not the Chilean Rosehair they think they sold to me.

My spider is also much bigger than the spiderlings in the two pics in the other post. I will try to take pictures tonight and post them tomorrow and ya'all can see what he looks like and how big he is. I hope I just have beginner's luck and got a nice spider - especially since I lucked out with the cost of him. :)
 
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Immortal_sin

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here is a male and female side by side for comparison. It does sound like you may have B smithi, not G rosea...as the B smithi is fairly distinctive...if so, you got one hell of a deal!
 
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Botar

Arachnoprince
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Aug 27, 2002
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SueinTX,

Looks like your questions have been answered. Welcome aboard. You'll find lots of friendly advice and answers to your questions here. A B. smithi will be relatively easy for you to sex at that size. Just check some of the threads on sexing T's and you should be set. Even if you do wind up with a male, there are plenty of people looking for male B. smithi for breeding exchanges. Good luck to you and keep us posted.

Botar
 

SueinTX

Arachnopeon
Joined
Dec 16, 2002
Messages
8
Immortal_Sin - that is what my spider

looks like. He looks like the one in your picture on the left (on the rock). Last night I put in one of those corner half logs and he seems to like it. He is out and about a lot. I love watching them walk.

I read also that you should not put their hiding place over the heat pad. Is this also true for the winter months? In southeast Texas where I live, it never gets very cold really, but it can get down to 67 degrees in my house. I also have him up on an entertainment center that is to the left of a big windown. He gets sunlight, but not direct.

Oh, he ate one of the three crickets that I put in there. The other two were removed last night. He is very very mellow about having your hand in there (he was not under a hiding place, he was just right out in the open in the middle in a warm spot) chasing crickets. He went into his hiding place when I was vacuuming in the room, but he seems pretty confident and mellow.
 

arachnopunks

Arachnobaron
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Nov 10, 2002
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You shouldn't need to provide a heat source for the Smithi unless the abient temperature in your house gets below 60 degrees. Tarantulas (burrowers anyhow) live underground and the temperature is never that high. It's a desert/scrubland species so the humidity given off by your water dish should be more than adequate. As a side note, if you suspect a molt (sluggish, overly-reclusive behaviour, and a noticeable web mat that the T seems to stay on) raise the humidity only slightly with a fine mist of water sprayed away from the T's location. We have always had great, problem-free molts with all of our T's when we raise the humidity a little. Enjoy your new T and welcome to a new addiction.
 

Immortal_sin

Arachnotemptress
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Jul 17, 2002
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the female is on the left, the male is on the right...he's a bit old, and missing quite a bit of abdomen hair!
If I use a heating pad (and I only do for the display Ts in the living room) I put it on the SIDE of the tank. Ts burrow and may burn themselves burrowing against the glass with the heating pad. B smithi is a very hardy tarantula though, and should stand normal household temps with no problem!
 
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