Aphonopelma bicoloratum? [2/2]
Hoxter

Aphonopelma bicoloratum? [2/2]

I'm trying to make sure seller wasn't wrong and it actually is an Aphonopelma bicoloratum and not B. boehmei. It's still pretty small, about 5cm long, molted about week ago.
Phone camera zoom allowed me to suspect it's also a female.
I’m going with this one being correctly labeled as Aphonopelma bicoloratum. One difference between Aphonopelma and Brachypelma is the shape of the carapace. With Aphonopelma, the carapace is longer than wide, with Brachypelma the carapace is more square (length and width about equal).

This one has a carapace longer than wide.
 
@AphonopelmaTX We see carapax slightly from side.
And what about these features of specimen ? :
- long hairs on legs (absent in bicoloratum)
- black markings around eyes (not always present in boehmei but never present in bicoloratum)
- darker "flame" on patela (uniform coloration in bicoloratum)
- black stripe on metatarsus (absent in bicoloratum)

bicoloratum is overaly differently looking animal.
 
@Patherophis All of the characters you listed are highly variable and not useful for identification. We are looking at a picture of a juvenile specimen after all. Carapace length and width ratio is stable in this circumstance when comparing Brachypelma and Aphonopelma, but not a useful character to make a more general generic ID.
 
@Hoxter I don’t think any additional pictures are necessary. This one is good. If you would like to remove all doubt though, a picture of the spermatheca from its next molt would make a positive ID possible. Aphonopelma and Brachypelma spermatheca are very different.
 
@Hoxter I would be thankful for more detailed photo of carapax directly from above, if possible.

@AphonopelmaTX While I agree that these single characters are quite weak and wouldnt be useful for serious taxonomy, I find combination of them all to be more than suggestive. Yes, carapax schape is good character, but I insist that it cannot be reliably read out of this photo. This photo is not showing specimen from above but from side. Try to rotate this photo to see how much off vertical axis it is.

@Exoskeleton Invertebrates May I ask You for opinion?
 
@Patherophis The characters you listed, even in combination, are not useful since Aphonopelma bicoloratum possesses many of them while B. boehmei doesn't posses one or two.

A. bicoloratum does in fact posses these characters:
long hairs on legs (absent in bicoloratum)
black markings around eyes (not always present in boehmei but never present in bicoloratum

While B. boehmei doesn't always have the black stripe on the metatarsus.
black stripe on metatarsus (absent in bicoloratum)

Instead of looking at and comparing photos of pet trade specimens which can be misidentified, search iNaturalist for these two species. iNaturalist is a great resource since the photos are of first-hand observations of wild specimens. There are several of B. boehmei and just one of A. bicoloratum.

For an authoritative source of using the carapace shape to differ Aphonopelma from Brachypelma, see the this CEC publication.
 

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Tarantula Identification
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Hoxter
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