Sexual Dimorphism in Asian Tarantulas

[Tbone192]

First and foremost, does C dyscolus exhibit sexual dimorphism? Couldn't find many specifics on sexing this species. I have seen a lot of MMs with lighter leg banding than confirmed females but I wanted to check.

For reference, I have 2 C dyscolus. Both molted recently, they are both about 3-4" DLS but one has much lighter legs than the other one. Before their most recent molts they looked identical.

Another I am curious about would be O violaceopes.

I am hoping this is a good thread for users to ask about specific Asian T species and how to sex them/ do they display dimorphism. Any posts helpful or inquisitive would be great. Thanks all.

 

[NMTs]

A quick search of the word "dimorphism" in thread titles yields at least 50 different threads on this subject...

Search results for query: dimorphism

The third result down is about O. violaceopes specifically. As far as I know, C. dyscolus does not display any differences until mature.

 

[viper69]

Another I am curious about would be O violaceopes

Yes upon male maturity

 

[Mike Withrow]

Most all asian spider's will show dimorphism when the males mature.
Totally different looking than the female and size. Loads of threads on this.

 

[Tbone192]

I don't mean leg and pedipalp ratios to the body ofc. I am interested in colour differences, patterns. If so what should I be looking for?

I have been reading many of the other dimorphism threads and chilobrachys sexing threads but these are probably most relevant threads I've found. Nothing specific, and specific is what I am looking for.

Chilobrachys dyscolus "Vietnam blue" [1/2]

Pardon the air hole sort of in the way but can anyone good at ventral sexing tell me if this chilobrachys dyscolus “Vietnam blue” is a male or female? (He/she is 2 inches long)

arachnoboards.com

Chilobrachys dyscolus "Vietnam blue" [2/2]

Can anyone tell if this 2 inch sling is male or female? Lots of hair on the abdomen

arachnoboards.com

Sexually Dimorphic Tarantulas

By request of BoyFromLA, I am creating this thread to be maintained by moderators, since regular users cannot edit their posts for more than 12–48 hours. Sexual dimorphism is when different sexes of the same species exhibit different morphological characteristics, particularly characteristics...

arachnoboards.com

 

[l4nsky]

There are some very clearcut and well recorded examples of early, premature coloration differences in Ornithoctoninae spp (like Lampropelma nigerrimum or Phormingochilus sp Akcaya), but nothing that I'm aware of for a Selenocosmiinae spp, like a Chilobrachys sp or an Orphnaecus sp. For the record though, my experience with the latter subfamily is rather limited.

 

[Tbone192]

I have a pair of C dyscolus that were the same size and they molted at similar times. These last molts have been interesting. One looks the same as it did but bigger and the other is not just bigger but also has significantly lighter legs, almost cream coloured. This one I suspect is a mature male. I could be wrong, I just can't find enough on the subject. I'll try to get some good pictures, hopefully soon.

 

[l4nsky]

Using a secondary sexual charachteristic like color in determining maturity isn't the best method IMHO, even though there are more species with noticeable color differences upon maturing than species that exhibit sexual dimorphism prematurely.

Mature males will have modifications to the end of the pedipalps called palpal bulbs and in some genera will have hooks on their legs as well. These are definitive indicators as opposed to "does this spider look to be a dark gray or a light charcoal to you?"

 

[Tbone192]

Using a secondary sexual charachteristic like color in determining maturity isn't the best method IMHO, even though there are more species with noticeable color differences upon maturing than species that exhibit sexual dimorphism prematurely.

Mature males will have modifications to the end of the pedipalps called palpal bulbs and in some genera will have hooks on their legs as well. These are definitive indicators as opposed to "does this spider look to be a dark gray or a light charcoal to you?"

I suppose that's fair. This was more of a curiousity. I've been looking at mating pictures and videos though, and I am starting to think that males do in fact have a significantly lighter colouration. There are of course a few variables to consider. I have some molts I'm rehydrating, that should shed some light on the situation.

 

[Olan]

Yeah, P. arboricola definitely can be sexed by front leg color when about 2- 3”.
I didn’t notice any difference between my C. fimbriatus slings, but wasn’t looking carefully.
Take some nice pics and then wait for maturity. Let us know if the color difference is predictive.

 

[Tbone192]

Molt confirmed that the suspect male is in fact male, though I do not know if they are quite mature yet. The other C dyscolus is a female confirmed. If anyone nearby has a female, I would be willing to snackrifice my male if it means potential slings, once my boy is ready ofc. Will try taking some pictures, male is always hiding though.

 

[Kada]

Some show extreme size differences as well, which is pretty obvious for some species. Augacephalus junodi comes to mind

 

[Mike Withrow]

Omothymus. V male's are super leggy and more of a moss green color when they have their final molt.

 

[8 legged]

There is no rule of thumb here, it depends on the species in question. In Chilobrachys kaeng krachan, for example, the female is dark and large, the male is beige and not even half as tall as the girl!

 

[Tbone192]

Finally got a picture of my male, he is definitely mature. You can clearly see the light banding on legs, lankier build, and beefy pedipalps.

MM ~ 3.5" received at 2"
Matured after 6 months under my care

NMF ~3.7" received at 2"
Believed to be not mature

The differences are quite striking, immature males look exactly like females. My male though, had very prominent pedipalps even before his final molt. If anyone lives in Western Canada, has a female, and is willing to breed then PM me. Happy New Year's !