Super Fat Aphonopelma chalcodes / Size differences

[Daniel Edwards]

I have 2 wild caught individuals that arrived in the same time, from the same company. Both have been fed equally (exactly). Both eat well. Both arrived with abdomens slightly smaller than the cephalothorax. Both are about 3-4" sub-adults or small adults. The one with the double sized abdomen (now) is very calm while the one with the smaller abdomen is skittish. My assumption is the one with the smaller abdomen may be suspect male and the very very plump one a suspect female although both have the same size exoskeletal structure.
The big ?... Has anyone ever received a gravid wild caught A. chalcodes? Why would one's abdomen get SO BIG vs. the other, when each one was fed the same amount of food? Same times? Same schedule? Same quantity? Thanks!

 

[boina]

I have 2 wild caught individuals that arrived in the same time, from the same company. Both have been fed equally (exactly). Both eat well. Both arrived with abdomens slightly smaller than the cephalothorax. Both are about 3-4" sub-adults or small adults. The one with the double sized abdomen (now) is very calm while the one with the smaller abdomen is skittish. My assumption is the one with the smaller abdomen may be suspect male and the very very plump one a suspect female although both have the same size exoskeletal structure.
The big ?... Has anyone ever received a gravid wild caught A. chalcodes? Why would one's abdomen get SO BIG vs. the other, when each one was fed the same amount of food? Same times? Same schedule? Same quantity? Thanks!

Hmmm... a gravid female filling her abdomen with eggs does come to mind. Getting gravind females is not unheard of - actually it happens quite regularly when adult females get cought.

 

[The Grym Reaper]

Could be gravid, there's always a chance of that with WC specimens but she could also make a phantom sac (a sac containing dud/unfertilised eggs).

I feed my WC AF chalcodes at the same time/rate as my CB AF A. geniculata (a superworm every two weeks) and she has a much smaller abdomen (in relation to carapace size) than the genic, you'd think it'd be the other way around.

 

[Daniel Edwards]

Could be gravid, there's always a chance of that with WC specimens but she could also make a phantom sac (a sac containing dud/unfertilised eggs).

I feed my WC AF chalcodes at the same time/rate as my CB AF A. geniculata (a superworm every two weeks) and she has a much smaller abdomen (in relation to carapace size) than the genic, you'd think it'd be the other way around.

True. I'll keep everyone posted.

 

[Daniel Edwards]

Hmmm... a gravid female filling her abdomen with eggs does come to mind. Getting gravind females is not unheard of - actually it happens quite regularly when adult females get cought.

Potentially! I'll keep us all informed.

 

[Dovey]

I have two chalcodes confirmed females from the same sac, but one will race ahead of the other in development and then they'll reverse. And their appearances will vary vastly from one molt to the next as adults. One is probably going through a fat phase.

Now if one shoots out in front of the other in terms of size and stays there, you probably have a male. They develop so much faster, so they put on a lot more size and weight earlier.

Do beware, though, that until that final molt, even experts can be fooled unless you have clear-cut endoscopic proof of gender. You go to bed with a fat and fluffy golden retriever who wants to sleep on the couch all day and wake up with a dark, leggy greyhound that just REALLY wants to get laid! :wideyed:

 

[boina]

Now if one shoots out in front of the other in terms of size and stays there, you probably have a male. They develop so much faster, so they put on a lot more size and weight earlier.

That's actually a myth:

http://arachnoboards.com/threads/males-growing-faster-than-females-myth.233628/

And an endoscope is something you put into things - Endo, Latin, meaning "inside" . I would not ever put something into a tarantula to sex it .

(Yes, I know, some people use things meant as an endoscope in different ways, but that's by no means the only, or even the best, way to sex a tarantula )

 

[Dovey]

That's actually a myth:

http://arachnoboards.com/threads/males-growing-faster-than-females-myth.233628/

And an endoscope is something you put into things - Endo, Latin, meaning "inside" . I would not ever put something into a tarantula to sex it .

(Yes, I know, some people use things meant as an endoscope in different ways, but that's by no means the only, or even the best, way to sex a tarantula )

Yep, just like MACRO photography by definition ought to mean pictures of galaxies, but rather--if you are a photographer--means making big pictures of tiny things.

Regarding size and sex, I am speaking from my own experience, definitely a limited survey group here with my local New River chalcodes only. But I sure have seen the biggest, fluffiest individuals of a clutch prove out to be penultimate males quite often.

 

[Dovey]

Frankly, when it comes to sexing tarantulas, I'm never completely satisfied until I see a successful breeding! I'd swear in a court of law that some of my "ladies" were trangendered!