25.09.2021

Aphonopelma sp. "Malinche" is most likely an Aphonopelma anitahoffmannae Locht, Medina, Rojo & Vázquez, 2005 

Recently we received an exuvia of a tarantula from Andreas Weger which he named Aphonopelma sp. "Malinche" or Aphonopelma serratum. Apparently the Spider originates from Mexico. Again the question was what it could be in reality or if this genus name is correct. Since there is no complete revision of the genus Aphonopelma, but only an excellent treatment of the species from the USA by Hamilton, Hendrixson & Bond (see references), it would be difficult to determine the species status of this exuvium [In the meantime, the female died and we were able to add this one to our study material as well (Pic 10, 11 & 12) . However, the first task was to verify the generic status. For this purpose, the genus diagnosis of Aphonopelma by Prentice (1997) was consulted. according to this, Aphonopelma possesses:

- no known external stridulation organs

No stridulation organ could be found in the exuvium. 

- hair-like or spiniform plumose setae on the prolateral surface of the trochanter (Pic 1) and femur of leg I (Pic 2) and on the retrolateral surface of the coxa and trochanter of the pedipalp (Pic 3).

In the present exuvium, there are indeed no feathered hairs at this point, or only at 400x magnification a certain "feathering" becomes visible (Pic 4). However, it may be doubted whether this structure is meant.. Nevertheless, we assume that this speaks for Aphonopelma, because those feathered hairs are difficult to find in this genus. 

- type I urticating setae only

In fact, we could find only type I urticating hairs (Pic 5)

- scopula of tarsus IV usually entire, if divided then only partially and narrowly by line of setae

This is also true. Only a slight division in the basal quarter of the tarsal scopula by some longer hairs is visible (Pic 6).

- setae on the prolateral surface of coxa I hair-like and not basally swollen, spiniform and basally swollen, or distinctly stout and thorn-like

This is also true. In the present case these black setae are thorn-like ( = spiniform) and basally swollen (Pic 1).

Whether this species is Aphonopelma serratum may be strongly doubted, because the female of this species is not yet known. A consultation with my esteemed colleague Steffen Esche resulted in the information that he also has doubts about this species diagnosis, because the bulb of this Aphonopelma sp. "Malinche" male, which he apparently already examined, has a different shape than that of Aphonopelma serratum. It should not remain unmentioned that the spermathecae form of the present exuvium shows a certain similarity to the illustration of Aphonopelma antitahoffmannae in Locht et al. (Pic 7 & 8) which, according to Steffen, also occurs not far from the locality of this A. sp. "Malinche". 

Resumé:

However, whether this Aphonopelma sp. "Malinche" is Aph. anitahoffmannae requires further investigation and research, especially of the male. So for now, Aphonopelma sp. "Malinche" should be referred to as Aphonopelma cf anitahoffmannae Locht, Medina, Rojo & Vázquez, 2005. A striking and interesting feature of this species is the long and dense red hairs on the underside of the body and femora ventrally (Pic 9). In the meantime we could examine 2 males of Aphonopelma sp. "Malinche" and find our diagnosis that this species is probably Aphonopelma anitahoffmannae confirmed -> see HERE!

Reference:

Hamilton, C. A., Hendrixson, B. E. & Bond, J. E. (2016). Taxonomic revision of the tarantula genus Aphonopelma Pocock, 1901 (Araneae, Mygalomorphae, Theraphosidae) within the United States. ZooKeys 560: 1-340.

Prentice, T. R. (1997) Theraphosidae of the Mojave Desert west and north of the Colorado River (Araneae, Mygalomorphae, Theraphosidae). Journal of Arachnology 25: 137-176.

Locht, A., Medina, F., Rojo, R. & Vázquez, I. (2005). Una nueva especie de tarántula del género Aphonopelma Pocock 1901 (Araneae, Theraphosidae, Theraphosinae) de México con notas sobre el género Brachypelma Simon 1891. Boletín de la Sociedad Entomologica Aragonesa 37: 105-108.