13.04.2023

Aphonopelma sp. „Malinche“ is indeed Aphonopelma anitahoffmannae Locht, Medina, Rojo & Vázquez, 2005 

In a report on the species identity of the tarantula species from Mexico, which is known in the Tarantula Community as Aphonopelma sp. "Malinche", on our Theraphosid Research Team website on 25.09.2021 we had raised a suspicion on the actual identity of this species by examining a female exuvium (see HERE). We suspected from the characters of the examined exuvia that this species could be Aphonopelma anitahoffmannae in reality. However, this had to remain a speculation for the time being, since we had not received a male for examination and comparison with the males of Aph. anitahoffmannae at that time. Thanks to Thorsten Thomas and to our friend and colleague Andreas Weger, who already provided us with the exuviae of this species at that time, we could now also receive 2 adult males of this species for our examination. The males are mostly similar to the exuvia of the female, so that we have no doubt that the examined males belong to the genus Aphonopelma and are conspecific to the female, whose exuvia we could examine at that time. In the meantime, unfortunately, also the female belonging to the exuvia has died and could be examined again. Also here the very remarkably long reddish shaggy hairs on the underside of the body and on the legs are very remarkable which Locht et al. also mentioned for Aphonopelma anitahoffmannae in their species description "Patas y pedipalpos marrón oscuro con sedas de guardia largas canela rojizo ..." (Pic 1 - 2) (Locht et al. 2005). Examination and comparison of the relevant characters of the present males of Aphonopelma sp. "Malinche" with the males of Aph. anitahoffmannae with respect to the structure of the tibial apophyses [compare Pic 3 (Aph. anitahoffmannae) with Pic 4 (Aph. sp. "Malinche")] and that of the bulbs shows no appreciable difference between the compared males of the two taxa. Aphonopelma sp. "Malinche" shows a high structural agreement in the prolateral and retrolateral bulb position (Pic 5) to the positionally identical illustration of the bulbs of Aph. anitahoffmannae in the species description of Locht et al. (Pic 6). Another indication for the affiliation of Aph. sp. "Malinche" to Aph. anitahoffmannae could be the locality. It is likely that the specimens available in the community under the name Aphonopelma sp. "Malinche" were caught in the area of "Malinche". Basically, we could find two localities that go under the term "Malinche" in Mexico, namely Malinche La in the state of Puebla and Malinche Norte, a municipality of Mexico City. Aphonopelma anitahoffmannae was also found in Mexico City, "Holotipo: ♂ y Paratipo ♀ procedentes de Ciudad Universitaria, México D.F.. (19º18'N, 99º11'W), 30 de junio de 2000 y 1 de julio de 2001 respectivamente, ambos recolectados por Arturo Locht, depositados en la CNAN,106 ubicada en el Laboratorio de Acarología del Instituto de Biología, UNAM." (Locht et al. 2005). Some will wonder why we do not speak of Dugesiella anitahoffmannae, because the tarantula hobbyist Ray Gabriel had recently taken this genus out of the synonymization with Aphonopelma and restored it and placed Aph. anitahoffmannae - without having examined (type) material - in the genus Dugesiella, with the type species Dugesiella crinita Pocock 1901 (Gabriel 2022). He justified the restoration of Dugesiella with the following difference of this genus compared to Aphonopelma "...the bulb of A. crinitum has two distinct denticulate keels...", while the bulb of "... Aphonopelma sensu stricto (...) have a single dendiculate keel.". He justified the transfer of the species Aphonopelma anitahoffmannae to the genus Dugesiella as follows "As mentioned by Locht et. al. (2005) the palpal bulb of A. anitahoffmannae possesses two denticulate keels similar to D. crinita comb. rest.., D. duplex comb. rest. and D. serratum comb. nov. Therefore, based on palpal bulb morphology illustrated in Locht et. al. (2005) it is propose A. anitahoffmannae also be transferred to the genus Dugesiella giving the new combination Dugesiella anitahoffmannae comb. nov." Locht et al. interestingly do not mention in their species description of Aph. anitahoffmannae that this species has TWO serrated keels. On the contrary, they mention in the species diagnosis concerning the keels of the male bulb only ONE serrated keel: "El bulbo ancho con la quilla prolateral inferior con dientes pequeños, lo distingue del resto de sus congéneres."! In the chapter "Comments" they also do not mention TWO serrated keels for this species, but only described that Aph. anitahoffmannae has the serration of keels in common with other species. Among others they mention Aphonopelma seemanni, which has only ONE serrated keel (Pic 7 + 8*): "Esta especie comparte la presencia de quillas dentadas en el bulbo pedipalpal con: A. crinitum, A. caniceps (Simon, 1890), A. duplex (Chamberlin, 1925), A. bicoloratum Struchen, Brändle y Schmidt, 1996, A. seemani, A. serratum (Simon, 1890) y A. stoicum (Chamberlin, 1925)." Pic 9 & 10* show this single serrated keel present in the two examined males of Aph. sp. "Malinche". 

Resumé: 

The fact of the high structural similarity of the genitalia and tibial apophyses of male Aphonopelma sp. "Malinche" and the number and position of serrated keels on the male bulb compared to these characters in Aphonopelma anitahoffmannae, which indeed also has only ONE serrated keel - contrary to the claim of Gabriel 2022(!!!) - leads us, together with the other similarities of both forms mentioned, to the conclusion that Aph. sp. "Malinche" is conspecific with Aphonopelma anitahoffmannae.

Basically, the diagnosis of the discussed genera raises the question whether the number of serrated keels can be a useful character for the differentiation of genera in view of the known strong structural variation of male keels within a genus (see for example the strong differences of keels and their structure of male Pamphobeteus species in Sherwood et al. 2022). In our eyes, the genus Aphonopelma sensu stricto may later even turn out to be monotypic, because Gabriel mentions in his 2022 publication for the male of Aphonopelma seemanni a very remarkable and hitherto mostly unknown character for tarantula males, namely a "...pair of apophyses on the ventro-medial metatarsus in adult males...." [Pic 11 (green arrow), 12 & 13). This character could possibly turn out to be an autapomorphy and thus a diagnostic character of the genus Aphonopelma sensu stricto. For this, however, an integrative phylogenetic character analysis is needed, because such an analysis usually explains the question of the relationships of species quite conclusively. In integrative phylogenetic character analyses, in which the topology of branching clarifies the degree of relationship by comparing as many homologous characters as possible, species can always be grouped into a genus if they share a common ancestor. In most cases, the apomorphies that define this node can often be used as good genus-diagnostic characters. In the question of the relationship of Aphonopelma sensu stricto with Dugesiella, such an integrative phylogenetic approach has not yet been performed or published.

For this reason, we continue to list the species Aphonopelma anitahoffmannae in the genus Aphonopelma rather than in the questionable genus Dugesiella with particular reference to the diagnoses of both genera in Gabriel 2022 and the information on the number of serrated keels of Aph. anitahoffmannae given in Locht et al. 2005.

* Pic 8 & 10 show the respective serrated keel in Aphonopelma anitahoffmannae (Pic 8) and Aphonopelma seemanni (Pic 10) after the bulb was bleached with hydrogen peroxide to make the structures more visible (von Wirth & Hildebrandt 2022).

Acknowledgements

We thank our friend and colleague Delfina Rynka for translating the species description of Aphonopelma anitahoffmannae by Locht et al. (2005) from Spanish into english language. 

Reference:

Gabriel, R. (2022). A new synonymy in the genus Aphonopelma Pocock, 1901 with notes on distribution, sexual dimorphism and colour variation in Aphonopelma seemanni (F. O. Pickard-Cambridge, 1897) and resurrection of the genus Dugesiella Pocock, 1901 (Araneae: Theraphosidae). Journal of the British Tarantula Society 37(2): 5-17. 

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.

Sherwood, D., Gabriel, R., Brescovit, A. D. & Lucas, S. M. (2022). On the species of Pamphobeteus Pocock, 1901 deposited in the Natural History Museum, London, with redescriptions of type material, the first record of P. grandis Bertani, Fukushima & Silva, 2008 from Peru, and the description of four new species. Arachnology 19(3): 650-674

Wirth, V. von & Hildebrandt, K. (2022). Bleaching of taxonomically important body structures in spiders using the example of tarantulas (Araneae: Theraphosidae). Journal of the British Tarantula Society 37(1): 34-41.