Ceratogyrus marshalli question

TalonAWD

Arachnoprince
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I have been wanting this tarantula for the longest but wanted slings. I wanted to see and document the horn growth. Not to mention the cool and unique factor of this tarantula. I waited till I saw some slings available and hopped on the deal.

So I now have two Ceratogyrus marshlli ~1.5" specimens and theres one question that has not been answered so far from my research.

From what I have seen the Mature male of this species does not have the horn like the female. (Reference: http://www.arachnoboards.com/ab/showpost.php?p=1569567&postcount=57) So this brings forth a question. I'm hoping someone with experience with this specific species can answer this.

I know that the females horn grows with each molt until it protrudes a good amount over her carapace. But what about the male? As he is growing, will he have a horn growing? Is this species of tarantula easy to sex by just looking at the carapace as juvies to see if the horn is growing? Or does the horn fall off on the males ultimate molt?

From the reference picture I linked above, the MM does not have a horn but just a stump.

Oh and Here are mine. They have some speed for sure! #1 and #2 Lots of fun{D



 

VESPidA

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those are great questions... i've been wondering about horn growth too. who did you buy from? they're definitely on my list.
 

TalonAWD

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those are great questions... i've been wondering about horn growth too. who did you buy from? they're definitely on my list.
I bought them from JungleCage. I have seen females for sale but I did not want one already grown. I wanted to actually see the horn grow so I could learn about this tarantula. To me its a rare specie to find as slings as I have been looking for many months. Under rated tarantula for sure. From the Horn, to the loud stridulating and that stocky look, its a really beautiful tarantula.
 

Zoltan

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I have 4 specimens, and only one of them has a foveal protuberance, the other three don't. 3 of them recently molted, the "horned" one's horn grew some, the others still don't have anything, so I'd say males will not develop a foveal protuberance at all, at least nothing like the "horn" of females.

Male specimen, premolt. The second picture shows well there's no "horn".





Female specimen, postmolt, eating first meal. She had a bit smaller, but still distinct "horn" in the previous instar.


 

TalonAWD

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I just found this....

Thats not a marshalli. Marshalli is my fave species, so it saddens me to tell you that. Marshallis are basically black at that age, you probably have a Pternochilus sp. (murinus) there. I would be very angry if sold a marshalli and it wasnt one :mad: Now, let me dispell some rumors; Only females ever get a horn, ceratogyrus is one of the only (if not the only) genus which has sexual dimorphism (different physical characteristics between Ms and fs). The males get a lil bump on their cephalathorax, but not a horn. At that size the female starts to sorta, maybe show a lil bit of a horn, but it doesnt really come along till its closer to 3 inches. Of my spiderlings that size, one of which is a marshalli and one is a bechuanicus, both have the slightest bit of a bump, but the bech, which is half an inch bigger is actually starting to form a horn that is pointing to the rear like the females of that species do. If you can get a reambursement then do it!! Nothing is as cool as Marshallis!! NOTHING!


From this thread http://www.arachnoboards.com/ab/showthread.php?t=26773
 

Zoltan

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They are about the same size, all of them are in the same instar (currently one still hasn't molted, so it's 1 instar behind). If the others were females, the "horns" would have to show by now.

Let me, too, dispell a "rumour": all species of tarantulas show sexual dimorphism, unless someone can present a species where mature males don't have palpal bulbs.
 

Dom

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Zoltan, how big are your specimens? There also seems to be a bit of color dimorphism in your specimens (?).
 

TalonAWD

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They are about the same size, all of them are in the same instar (currently one still hasn't molted, so it's 1 instar behind). If the others were females, the "horns" would have to show by now.

Let me, too, dispell a "rumour": all species of tarantulas show sexual dimorphism, unless someone can present a species where mature males don't have palpal bulbs.
Thanks. So I got my answer. Males have no horn, females have horns. And yes once mature if pretty obvious but I think the poster of that quote is geared towards juvies and not mature specimens.

If this species had a horn whether male and female as juvie/subadults, than the only way to sex them is by molt of take a chance at the ventral shot. That statement would no longer be true about sexual dimorphism.
 
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