Sexually Dimorphic Tarantulas

[Ungoliant]

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 not directly involved in reproduction. The following species have been observed to exhibit sexual dimorphism. Since all mature male tarantulas have palpal emboli, and many have spurs or “hooks” on the tibia of their front legs, this list focuses on tarantulas that exhibit other differences.

• Ceratogyrus marshalli: only females grow horns; males just have little “buttons”
• Monocentropus balfouri: mature males often sport a deep blue carapace
• Ornithoctonus aureotibialis
• Poecilotheria metallica

If you have firsthand knowledge of an additional species that exhibits sexual dimorphism, you can reply to this thread to have it added to this post. Please include a description of the differences (and photos if you have any of your own that illustrate these differences).

 

[HooahArmy]

The Lampropelma violaceopes, or 'Singapore Blue' is also a notable species. The females are a vibrant bluish-purple with a tan carapace, while the male are surprisingly brownish gold!
Here are some photos from our aracho-members @curtisgiganteus and Dman.
Female: https://arachnoboards.com/gallery/18282d60-6d6d-4e5b-b6ad-0e059774195e-jpeg.85708/
Male: https://arachnoboards.com/gallery/o-violaceopes-just-matured.67899/

 

[viper69]

Are you including dimorphic upon maturity AND dimorphic before maturity?

 

[BoyFromLA]

Are you including dimorphic upon maturity AND dimorphic before maturity?

Anything that notably distinguishes the differences between a male and a female, upon and before maturity.

 

[TLSizzle]

So something like MM A chalcodes have black legs and females have brown/ tan legs is what you are looking for?

 

[viper69]

1.0 irminia males change color to gray all over and females only are black

0.1 C versi have a white dot on their upper lip

1.0 P rufilata have a dot just above their vent

All Ceratogyrus that grow a horn are female, males have “buttons” Maybe there’s an exception but I am not aware of that.

 

[TLSizzle]

0.1 C versi have a white dot on their upper lip

Curious, what do you mean by "lip"?

 

[HooahArmy]

Ah! Many Pamphobetus also have males that are significantly brighter than the females. While the males can display striping, purples, bright oranges, and are mostly ganglier and smaller; the females tend to be a muted variation of the male's color, or on occasion, just brown or tan.
Here are photos of a P. ultramarimus from our users, @NukaMedia Exotics and @heiwut819
Female: https://arachnoboards.com/gallery/pamphobeteus-ultramarinus-adult-female.77895/
Male: https://arachnoboards.com/gallery/mm-pamphobeteus-ultramarinus.89256/

 

[SpookySpooder]

Ornithoctoninae sp. Vietnam Silver is another sexually dimorphic species.

Both look the same until maturity, then males turn brown and females remain silvery-blue black with golden setae.

 

[Hydrazine]

Psalmo mature males in general turn grey and super fuzzy, as far as I know.

 

[AphonopelmaTX]

Sexual dimorphism is when different sexes of the same species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The following species have been observed to exhibit sexual dimorphism. Since all mature male tarantulas have palpal emboli, and many have spurs or “hooks” on the tibia of their front legs, this list focuses on tarantulas that exhibit other differences.

I'm really confused by the point of this post. All spiders- which includes the tarantulas of course- are sexually dimorphic which includes not only the reproductive organs but the change in the ratio between leg length and body length in the males. Differences in coloration before or after reaching maturity in either males or females is really best shown in pictures using correctly identified individuals.

Also, the misuse of the term "palpal emboli" needs to be corrected. The structure attached the transformed palpal tarsi (called a cymbium), which males use for copulation, are called palpal bulbs. The embolus (plural emboli) is just the shaft-like structure at the end. The technical term for the embolus is 'distal sclerite' and can take on many different shapes and sizes.

 

[viper69]

Curious, what do you mean by "lip"?

Have you ever sexed a female tarantula ventrally?

 

[BoyFromLA]

I'm really confused by the point of this post.

It was originally me who requested for the post.

The whole point of me requesting this was to have gathered informations of ‘sexual dimorphism’ in tarantulas, so that for people even without proper knowledge how to ventral or with molts sexing, can at least distinguish a male from a female.

All spiders- which includes the tarantulas of course- are sexually dimorphic which includes not only the reproductive organs but the change in the ratio between leg length and body length in the males.

But yes, you are right.

 

[Wolfram1]

@AphonopelmaTX already said it but technically they are all sexually dimorphic.

I am also confused, i thought this was ment to be a post about early signs not mature spiders....



like for example:

Poecilotheria ornata sexual dimorphism

Starting a new thread so it's easier to find. :) The only species of Poecilotheria that can be accurately sexed dorsally at a young age is P. ornata. The other species sometimes can when larger sub adults but not always, it differs per individual. Hence why it is not accurate. Never go by folio...

arachnoboards.com

...unlike ventral sexing/sexing by epiandrous fussillae that focuses basially on the genitalia, which are different no surprises there

though they can be hard to tell apart when young, its not part of what i assumed this post was about.

Another example that fit my interpretation would be Phormingochilus arboricola and i am sure a few others like Lampropelma niggerrimum or L. carpenteri were the juvenile females turn black while the juvenile males retain a lighter colour.

 

[vounti]

Another example that fit my interpretation would be Phormingochilus arboricola and i am sure a few others like Lampropelma niggerrimum or L. carpenteri were the juvenile females turn black while the juvenile males retain a lighter colour.

Here with pictures

Lampropelma sp. 'Borneo' sexual dimorphism

Lampropelma sp. 'Borneo' males start showing tarsus and metatarsus coloring early as two inches. 2" Male Leg I tarsus and metatarsus 2" Female Leg I tarsus and metatarsus By 3" the males other legs have gained the colors......... 3" Male 3" Female When the...

arachnoboards.com

 

[Ultum4Spiderz]

King baboon is pretty diphmorphic as far as size is concerned. https://en.m.wikipedia.org/wiki/King_baboon_spider

 

[CrazyOrnithoctonineGuy]

As mentioned, Phormingochilus arboricola, even before maturity.

Just about every arboreal ornithoctonine is sexually dimorphic at maturity (all the males are dull grey/greenish brown, the females have their species' characteristic colors), though I'm not sure how many of them are dimorphic before maturity.

 

[arthurliuyz]

@BoyFromLA By your definition, don't almost all Ornithoctoninae spp. and Selenocosmiinae spp. fit in the distinctively-sexual-dimorphic-wwhen-mature category? It'd be much more useful if the point of this thread is to share species that can be sexed dorsally, without ventral or molt sexing at an early age, IMHO.

 

[TheHound]

Ah! Many Pamphobetus also have males that are significantly brighter than the females. While the males can display striping, purples, bright oranges, and are mostly ganglier and smaller; the females tend to be a muted variation of the male's color, or on occasion, just brown or tan.
Here are photos of a P. ultramarimus from our users, @NukaMedia Exotics and @heiwut819
Female: https://arachnoboards.com/gallery/pamphobeteus-ultramarinus-adult-female.77895/
Male: https://arachnoboards.com/gallery/mm-pamphobeteus-ultramarinus.89256/

Same with Xenesthis.

 

[klawfran3]

As mentioned, Phormingochilus arboricola, even before maturity.

Just about every arboreal ornithoctonine is sexually dimorphic at maturity (all the males are dull grey/greenish brown, the females have their species' characteristic colors), though I'm not sure how many of them are dimorphic before maturity.

AFAIK there aren't any tarantulas that are sexually dimorphic before maturity. I personally suspect maybe the Orni. Sp. Vietnam silver could possibly be, but I'm not holding my breath and we need a lot more research on them to be sure. I'm hoping to breed mine and keep a few to see the possibility. Either way it's unlikely since no other species is.