30.09.2023

Is Aphonopelma mooreae Smith, 1995 really this species in the hobby?

When the first pic of the female of the beautifully colored Aphonopelma mooreae Smith, 1995 appeared in the tarantula community (Pic 1*), we initially had great doubts that it would really be this species, because so far only the male of this species is scientifically described. How could anyone identify a female as Aph. mooreae without knowledge of its characters?

Recently we received an adult male of this species preserved in 70% isoprphyl alcohol from the Belgian tarantula friends Oly Lenskens and Michael Heylen (Pic 2*). Thus we could now attempt an identification of this male. As a reference we used the original description of Aphonopelma mooreae by Andrew Smith from 1995. Special attention was paid to the comparison with the illustrations in the first description of Smith 1995 concerning the genital morphology and structure of the tibia apophyses and spination of the palps and tibiae of the 1st pair of legs, because these taxonomically useful characters are known to be very good characters for species identification, because these structures evolve only very conservatively.

First, we compared the structure and arrangement of the spines of the palps prolateral to the present male with the data in the original description.

Pic 3 shows this structure from Smith's original paper. The comparison with the photo of the examined male (Pic 4) shows a certain agreement in the spination (green circles) with the holotype. Only on the femur there is just 1 spine in the present male and the ventral spine in the holotype is clearly located more basally on the tibia in the present male. However, the spination indicates a clear relationship similarity of the present male to Aph. mooreae due to its similar arrangement of spines.

Comparison of the tibial apophyses and spination of the tibia of the 1st pair of legs from the examined male (Pic. 5) with the illustrations in the original description (Pic. 6) also shows high agreement in the structure of the tibial apophyses. The present male also shows a large spine on the inner side of the smaller apophysis (Pic 6).

Also, the examined male possesses the same large spine on the prolateral side of the tibia of the 1st leg (Pic 7) as in the holotype (Pic 8). However, the present male has a 2nd spine on this side of the leg segment (Pic 7, green circles).

The distribution of the cuspules on the labium and maxillae of the examined male (Pic 9, green markings) shows small differences to the holotype (Pic 10), but these differences are not of great relevance for the question of the relationship of the male to the holotype of Aph. mooreae, because the distribution and number of cuspules is subject to a certain individual variation. Thus it is not surprising that in the present male the spreading of the cuspules is not quite as extensive as in the holotype.

The most certain indication for a very close relationship of the present male with the holotype is the high similarity in the structure of the bulb and the embolus. The genital morphology, especially of the male bulb, is considered a very good character in comparison and differentiation of spider species. The present male shows the same shape and structure of the bulb (Pic 11) as in the holotype (Pic 12).

Also, the structure and keeling of the embolus tip of the examined male (Pic 13) agrees with the drawing of Smith 1995 with respect to this character (Pic 12, above).

Smith mentioned regarding the distribution of the scopula on metatarsus 4 that in the holotype of Aphonopelma mooreae it is less than 1/3 distributed on the leg segment. His drawing in this context, however, shows a distribution that is slightly more than 1/3 of the length of metatarsus 4. The present male also has a distribution of the scopula on metatarsus 4 that is slightly more than 1/3 of the length of the leg segment (Pic 14) and thus at least agrees with the drawing in Smith 1995.

Resumé:

Due to the high similarity regarding the relevant taxonomic structures of the present male with the description of Smith 1995 regarding the holotype of Aphonopelma mooreae, we consider it very likely that the examined male will indeed be Aphonopelma mooreae Smith, 1995. Although Smith does not mention a blue coloration of the holotype, the absence or fading of this coloration may be due to the longer storage in alcohol as well as to the different color patterns of the different populations of a species, as we can often find in tarantulas (see e.g. the different color forms of Pterinochilus murinus). Even an individual variation in coloration is not uncommon in tarantulas, for this reason an identification based on the habitus and especially based on the coloration of tarantulas is in most cases not very accurate and should for this reason always be based on the comparison of taxonomic characteristics. Who originally identified these spiders in the tarantula community as Aphonopelma mooreae is not known to us, but it was a good one, because he was obviously correct with his diagnosis.

Reference:

Smith, A. M. (1995). Tarantula spiders: tarantulas of the U.S.A. and Mexico. Fitzgerald Publishing, London, 196 pp.

*= Pics courtesy of Oly Lenskens & Michael Heylen