31.12.2024
Why you can't identify tarantulas by their appearance!
On the last weekend of 2024, during a visit to our friend Oly Lenskens in Belgium, we received an adult male tarantula that he had in his collection named “Hapalotremus sp.” from the Los Pinos - Cochas Chico, Ecological Park area in Peru (pic 1). He had even bred this species. However, pics of these spiders led to the opinion in various international tarantula discussion groups that it would probably be a Thrixopelma. Oly took the opportunity of our visit and asked us to examine the adult male to determine which genus the male actually belonged to. After we had prepared the most important identification features for the examination, we compared the features of the male in relation to his bulb structure, structure of the tibial apophyses and the shape of the palp tibia with the information on the males of the genus Thrixopelma by Sherwood et al. (2021) and Sherwood & Gabriel (2022, 2024) and were able to determine very quickly that this male shows no similarity to Thrixopelma in terms of the taxonomic characters mentioned and thus does not belong in this genus. Next, we dealt with the revision of Hapalotremus by Ferretti et al. (2018). It quickly became apparent that the male of Oly Lenskens is indeed a Hapalotremus. In our opinion, the species most closely related to this male appears to be Hapalotremus major (Chamberlin, 1916). The following character matches speak in favor of Hapalotremus (major):
· The representatives of the genus Hapalotremus have a small field of spine-like setae (pic 2, from Ferretti et al. 2018) on the palp coxa retrolaterally. Such a field is also found in the present male (green circle in pic 3 and pic 4 in close-up).
· The present male has type 3 urticating hairs (pic. 5), which indicates that it belongs to the Hapalopini and is identical to the urticating hairs of the other Hapalotremus species.
· The structure of the tibial apophyses matches the figures for Hapalotremus major. The small prolateral apophysis has a large spine on its inner side, which is almost as long as the apophysis. The large apophysis ends in a pointed spine (pic. 7). The same structure is found in Hapalotremus major (pic. 8, from Ferretti et al. 2018).
· Most Hapalotremus species unusually lack scopula on the underside of Metatarsus IV (pic. 9, from Ferretti et al. 2018). The present male also has no scopula there (pic 10).
· The structure of the bulb (pic 11) and the rounded process on the palp tibia (pic 11, green arrows) are almost identical to the same structures in Hapalotremus major (pic 12 from Ferretti et al. 2018).
Resumé:
The examined adult male of a possible Hapalotremus species from Peru actually belongs to the genus Hapalotremus based on its taxonomic characteristics and is apparently the closest relative to the species Hapalotremus major in terms of its taxonomically useful identification features and, in our opinion, could be named Hapalotremus aff. major for the time being. Hapalotremus major is also the described Hapalotremus species that is closest to the site where the present male was found. Both sites are only about 370 kilometers apart. However, the male in question is definitely not a representative of the genus Thrixopelma, as has been carelessly claimed in some forums and Facebook groups based on its appearance. This example shows very well that in most cases it is not possible to identify tarantulas based on their appearance.
Reference:
Pic 1.jpgPic 2.jpgPic 3.jpgPic 4.jpgPic 5.jpgPic 7.jpgPic 8.jpgPic 9.jpgPic 10.jpgPic 11.jpgPic 12.jpg