Acanthoscurria geniculata (C. L. Koch, 1842)

Distribution: Brazil

Adult female (RKCP 0078), origin unknown.

Spermatheca of adult female (RKCP 0078), origin unknown.

 

Adult male (RKCP 0282). According the annotation cited below this male probably belongs to Acanthoscurria brocklehursti F. O. P.-Cambridge, 1896 due to the absence of PAc keel located between PS and PI keel.

Male tibia I (RKCP 0282). One tibial apophysis of leg I  ending by a row of short spines is one of the generic characters of the genus Acanthoscurria Ausserer, 1871.

Male palpal bulb (RKCP 0282, origin unknown) with two distinct keels (PS, PI), short apical keels (A) and weakly developed PAc between PS and PI keel, retrolateral view.

Male palpal bulb (RKCP 0282, origin unknown) with two distinct keels (PS, PI), short apical keels (A) and weakly developed PAc (hardly visible) between PS and PI keel, prolateral view.

 

Annotation of Richard Gallon to closely related species Acanthoscurria geniculata and A. brocklehursti (September 18, 2004):

http://www.the-t-store.co.uk/forum/index.php?showtopic=8382

"Given the recent interest regarding these two species I decided to check the bulbs to see if there were any obvious differences (given that the two species are often confused in captivity).

As you can see the palpal bulbs of Acanthoscurria geniculata & A. brocklehursti are similar suggesting they are closely related species (not surprising giving their coloration similarities).

Fortunately there is a significant, easily seen means to separate them:

In Acanthoscurria geniculata an extra keel is present between the two major ones on the embolus.

I've compared the shape of the captive geniculata bulb with a photograph of Koch's type male and am happy this species is correctly identified (the size and curvature of the keels are consistent, although the photo was taken at an angle where you can't see the middle-keel).

Whether captive brocklehursti are conspecific with real brocklehursti we can't be 100% sure, but in the absence any evidence to the contrary (and given that they are phenotypically identical to dry material in the BM - presumable ID'ed by Cambridge himself), I see no reason to doubt it at the moment.
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