02.12.2024
Why “Pseudhapalopus sp. Colombia/Yellow-Blue” is not a Pseudhapalopus species!

For some years now we have had a tarantula species from Colombia in the community with the name “Pseudhapalopus sp. Colombia”. Sometimes it is also offered as “Pseudhapalopus sp. Yellow-Blue” (Pic 1). We have long wondered how the genus name “Pseudhapalopus” could actually be established for this species, as the genus Pseudhapalopus was described in 1907 by the Norwegian entomologist Embrik Strand (Pic 2) on the basis of the species Pseudhapalopus aculeatus. The genus was therefore monotypic, consisting of only this one species, and thus the generic characteristics were defined only by the single specimen of this species, an adult male. However, this species has since been declared a nomen dubium by Nentwig et al (2020), as this single reference specimen of this species and genus was destroyed in WWII and thus no longer exists. Unfortunately, Strand's description is so poor that it would be impossible to identify a true Pseudhapalopus with certainty. Gabriel & Sherwood also noted this in a 2020 paper. For this reason, they transferred the species previously known as Pseudhapalopus spinulopalpus, which Schmidt and Weinmann had described in 1997 in the genus Pseudhapalopus, to the newly established genus Spinosatibiapalpus. Due to the destroyed holotype of the type species of Pseudhapalopus, it is not possible to correctly assign a tarantula to this genus, which is why the establishment of a new genus for Pseudhapalopus spinulopalpus became necessary. The question then arises as to which genus “Pseudhapalopus sp. Colombia/Yellow-blue” belongs to.
To clarify this, we examined males and females of this form from our collection. We primarily focused on the characteristics of the males, as these are usually more meaningful and stable compared to the female characters. This applies in particular to the genital morphology. It quickly became obvious that this “Pseudhapalopus sp. Colombia/Yellow-Blue” is another, but previously undescribed Spinosatibiapalpus species. The reason for this is as follows.

The generic diagnosis of Spinosatibiapalpus in Gabriel & Sherwood 2020 is as follows:

"Spinosatibiapalpus gen. nov. can be distinguished from other theraphosine genera by the heavily spinose male retrolateral*1 palpal tibia (Figs. 24, 34, 41) along with the morphology of the male palpal bulb which possesses a tegular process, with weakly developed or developed PS, PI, A, SA and RS. RI keel is absent, PI keel running almost half the length on the embolus. (...) Females can be distinguished from other theraphosine genera with twin spermathecae by the morphology the short, squat, retrolaterally bowed receptacles, emerging medially from ovate GP, higher than their width, with almost the length of a single GP at their apical separation (Figs. 25-26)."

The present male of “Pseudhapalopus sp. Colombia/Yellow-Blue” has exactly this strong spination on the prolateral side (see footnote) of the palptibia (Pic. 3). The single domed retrolateral apophysis on the palpal tibia, typical for Spinosatibiapalpus, is also present in the present male (Pic 4 - dorsal & Pic 5 - retrolateral). The spermathecal morphology of the present female of “Pseudhapalopus sp. Colombia/Yellow-Blue” also agrees with the genus diagnosis (Pic 6). The bulb of the present male is also very similar to the bulb of Spinosatibiapalpus spinulopalpus shown in Gabriel & Sherwood (Pic 7), which also originates from Colombia, both in its shape and in the structure and shape of the aforementioned keels (Pic 8). However, “Pseudhapalopus sp. Colombia/Yellow-Blue” differs from it, for example, by 2 spines on the tibia 1 retrolateral apical, which are not present in S. spinulopalpus (Pic 9). Furthermore, this species differs from Spinosatibiapalpus spinulopalpus by the remarkably blue and yellow coloration in the female (Pic 2) (cf. Fig 27 in Gabriel & Sherwood 2020). The present male differs from Spinosatibiapalpus tansleyi, S. trinitatis, S. bora by the presence of a tibial apophysis on leg 1 and by a different bulb structure. The “Pseudhapalopus sp. Colombia/Yellow-Blue” differs from S. cambrai by the different bulb and spermathecal structure and by the significantly larger area of spines on the retrolateral palptibia in S. cambrei. "Pseudhapalopus sp. Colombia/Yellow-Blue” differs from S. paula and S. neisi by the presence of the blue-yellow body coloration as well as the bulb structure and by the structure of the tibial apophysis and its number of spines which are clearly more numerous in S. paula and by the absence (Pic 10) of a second smaller tibial apophysis which is present in S. neisi.

Resumé:

During the examination of “Pseudhapalopus sp. Colombia” / “Pseudhapalopus sp. Yellow-Blue”, known in the tarantula community under these common names, it could be shown that it is actually an undescribed species of the genus Spinosatibiapalpus, which should therefore actually and correctly be called Spinosatibiapalpus sp. “Colombia” or Spinosatibiapalpus sp. “Yellow-blue”. The genus Pseudhapalopus cannot currently be defined and thus correctly identified due to the lack of the holotype of the type species. The generic name in the common name for this species was therefore at least dubious from the outset.

Reference:

Gabriel, R. & Sherwood, D. (2020). Revised taxonomic placement of Pseudhapalopus Strand, 1907, with notes on some related taxa (Araneae: Theraphosidae). Arachnology 18(4): 301-316.

Nentwig, W., Blick, T., Gloor, D., Jäger, P. & Kropf, C. (2020). How to deal with destroyed type material? The case of Embrik Strand (Arachnida: Araneae). Arachnologische Mitteilungen 59: 22-29.

*1) In fact, the spines are located on the prolateral side of the palptibia. Gabriel & Sherwood had obviously made a mistake here, because the pics of this structure to which they refer in their paper also show this structure on the prolateral side.