Anomalobuthus rickmersi Kraepelin, 1900

Teruel, Rolando, Kovařík, František & Fet, Victor, 2018, Revision of the Central Asian scorpion genus Anomalobuthus Kraepelin, 1900, with descriptions of three new species and a generic synonymy (Scorpiones: Buthidae), Euscorpius 270, pp. 1-45 : 3-11

Anomalobuthus rickmersi Kraepelin, 1900

Figures 1–33, 117–119, 126–127, 137, 141; Tables 1 , 4–5

Anomalobuthus rickmersi Kraepelin, 1900: 1–11 , figs. 4–7; Birula, 1904: 32; Birula, 1905: 449 (in part); Birula, 1911a: 73–74 Birula, 1911b: 171 (in part); Rickmer Rickmers, 1913: 442; Birula, 1917: 112 (in part); Pavlovsky, 1934: 201 (in part). Werner, 1934: 272; fig. 341; Weidner, 1959: 98; Stahnke, 1972: 122 (in part), fig. 3; Vachon, 1974: 908, fig. 37; Fet, 1980: 224 (in part); Fet, 1989: 80 (in part); Sissom, 1990: 37, 46, 48– 51, 96, 101, 120, figs. 3.17h, m; Fet, 1994: 531 (in part); Gromov & Kopdykbaev, 1994: 20 (in part); Fet et al., 1998: 613 (in part), fig. 6 [specimen from Repetek]; Fet & Lowe, 2000: 75 (in part, includes full list of references before 1998); Fet et al., 2001: 183–185, tab. 1 (in part). Fet et al., 2003: 4 (in part); Fet et al., 2005: 2– 3, 6–7, 10–11, 13, 22, 24–25, figs. 10, 23–25, tab. 1 (in part); Graham et al., 2012: 95–96 (in part); Warburg, 2013: 96, 102 (in part); Teruel et al., 2014: 1, 4, 6–7, 9, fig. 20, tabs. 1–2 (in part). Nec Lourenço, 2001: 15–20 [misidentification, see below in Remarks section].

HOLOTYPE ♂ ( ZMUH, examined). Tajikistan, Khatlon Province, Kyzylsu River valley , near Baljuvon (= Bal'dzhuvon or Baljuan), early summer 1896, leg. W. Rickmer Rickmers. See discussion below, in Remarks section.

OTHER MATERIAL EXAMINED. Turkmenistan, Karakum Desert, Lebap (= Chardzhou) Province , Repetek Nature Reserve , 38°33'54"N 63°10'51"E, 201 m a.s.l., 21 July 1985, leg . V. Fet, 2♂♂ ( NHMW), 5♂♂, 1 juvenile ( VFPC); same data except 29 April 1967, leg . V. I. Kuznetsov, 1♂ ( ZSRO Sc-1249); same data except 15 April 2002, leg . V. Fet, 1 juvenile ( VFPC); Karakum Desert, Akhal Province, Tejen (= Tedzhen , Tedschen ), 37°22'39"N 60°29'52"E, 188 m a.s.l., 10–24 July 1904 [23 July–6 August], leg. K. Aris, 1♂ ( ZISP 809 ); Mary Province, Serkhetabad District , Badghyz Plateau , Chainury , 35°40'52"N 62°01'34"E, 458 m a.s.l., 6 April 2002, leg . V. Fet & A . V. Gromov, 1♀ ( FKCP), 1♀ ( NMPC) .

DIAGNOSIS (emended). Adult size 30–34 mm in males, 32–37 mm in females. Coloration light yellow, essentially immaculate, only with some regular blackish spots on pedipalps and metasoma (darker and more extended in female); metasomal segment V and telson reddish brown (male) to black (female). Pedipalp fingers with 9–10 principal rows of denticles and 7–9 internal accessory denticles. Pectines with 23–27 teeth in males and 20–23 in females. Tibial spur variable from absent (specimens from Turkmenistan) to present but very small on leg IV only (male holotype from Tajikistan). Metasoma conspicuously attenuate, with most carinae obsolete to vestigial; ventral lateral carinae of segment V composed of denticles narrowly conical (male) to narrowly lobate (female), dorsal lateral and lateral supramedian carinae of segments I–IV with terminal denticle enlarged; intercarinal spaces essentially smooth on segments I–III, sparsely granulose on ventral and lateral areas of IV and very densely granulose on ventral and lateral areas of V (granulation sparser in female). Telson vesicle elongate oval and sparsely setose.

REDESCRIPTION (adult male holotype). Coloration ( Figs. 1–2) moderately faded and translucent due to long preservation, but still reliably traceable. Base light yellowish; in general, the base color is paler on pedipalp chelae, legs, and pectines. Chelicerae immaculate, except for dark brown finger teeth. Pedipalp femur and patella with internal surface infuscate; chela immaculate, only with finger denticles dark brown. Carapace immaculate, only with a blackish spot under every ocular group. Tergites immaculate. Coxosternal region and genital operculum immaculate. Pectines pale yellowish, immaculate. Sternites immaculate. Legs essentially immaculate; claws with distal half dark brown. Metasoma not conspicuously bicolor, only becoming progressively darker and redder distally, segments I–IV with a diffusely annulated appearance (basal and distal parts of each segment faintly infuscate as thin brown rings, which become larger and more diffuse dorsally) and segment V faintly infuscate, becoming progressively darker and redder distally; carinae not infuscate nor underlined with dark pigment. Telson vesicle reddish brown, aculeus with basal half yellowish and distal half dark brown.

Chelicerae ( Fig. 10). With dentition typical for the genus, as described for A. krivochatskyi sp. n. (see below).

Pedipalps ( Figs. 14–22). Relatively short but very slender, essentially bare. Femur subtly curved inwards, with carinae weak, granulose to subdenticulate; intercarinal tegument smooth and glossy. Patella straight, with carinae obsolete to absent, smooth except on internal surface where vestigially denticulate; intercarinal tegument smooth and glossy. Chela elongate and very slender; manus conspicuously narrower than patella (ratio 0.79), subcylindrical (1.80 times longer than wide, 1.07 times wider than deep), with carinae weak to moderate, smooth; intercarinal tegument smooth and glossy; fingers very long (movable finger 2.44 times longer than underhand), only subtly curved and with 10 principal rows of denticles (the two basalmost rows are moderately well-defined), basal lobe/notch combination absent, external accessory denticles absent, internal accessory denticles very large and claw-like (increasing in size distally), numbering eight on both fixed and movable fingers, movable finger with one claw-like accessory denticle basal to the very large terminal denticle.

Carapace ( Fig. 10). Very strongly trapezoidal (much narrower anteriorly) and wider than long; anterior margin shallowly convex, with 5–6 pairs of thin macrosetae and some very short microsetae. Carination essentially absent: the only carinae present are the superciliaries, which are smooth. Furrows: anterior median, median ocular, central median, posterior median and posterior marginal fused, wide and moderately deep; lateral oculars, lateral centrals, central transverse, and posterior laterals long, narrow and shallow. Tegument very finely and densely granulose, with a few small to medium-sized granules scattered all over.

Sternum ( Fig. 11). Standard for the genus, relatively small and widely triangular in shape.

Genital operculum ( Fig. 11). Slightly damaged. Relatively large, each half roundly subtriangular in shape. Genital papillae present.

Pectines ( Fig. 11). Standard-sized for the genus: very long, extending beyond leg IV coxa-trochanter joint), subrectangular and densely setose. Tooth count 25/25. Basal plate heavily sclerotized, much wider than long, anterior margin with a very deep, narrow anteromedian furrow, posterior margin very shallowly convex.

Legs ( Figs. 12–13). Very slender, with all carinae weak and subgranulose to subcostate; intercarinal tegument smooth and glossy. Tibial spurs entirely absent on legs III, reduced to a sinuous remnant on legs IV.

Mesosoma ( Figs. 10–11). Tergites with the same sculpture as on carapace; I–VI irregularly tricarinate: the median longitudinal carina is weak, short, and formed by irregular medium-sized granules that do not project beyond posterior margin, but the submedian carinae are defined only by few coarse granules irregularly aligned; tergite VII with five well-defined carinae: the median carina is very short but strongly subserrate, the submedians and laterals are long, strong and finely serrate to denticulate. Sternites sparsely setose; III–VI glossy and with very subtle vestiges of smooth submedian carinae, spiracles relatively short and slit-like, almost transversely arranged (not strongly oblique), V with smooth patch absent; VII with two pairs of carinae: the submedians are long and finely crenulate to subcostate and the laterals are very short and subcrenulate, intercarinal tegument coriaceous to minutely granulose.

Metasoma ( Figs. 23–25). Elongated and slightly wider subdistally; with 10/10/10/8/5 complete to almost complete carinae, almost all obsolete to vestigial and smooth, with coarse punctations scattered: dorsal laterals very weak on I–III (with one terminal denticle enlarged), obsolete to vestigial as rounded ridges on IV, absent on V; lateral supramedians very weak on I–III (with one terminal denticle enlarged), obsolete to vestigial as rounded ridges on IV–V; lateral inframedians obsolete on I–III, absent on IV–V; ventral laterals obsolete on I– IV, weak to moderate on V, where become progressively stronger and somewhat flared distally, formed by sharply serrate, subequal denticles; ventral submedians obsolete on I–IV, absent on V; ventral median absent on I–IV, weak to moderate on V. Intercarinal tegument smooth and glossy, with minute but sharp granulation on lateral and ventral surfaces, which become much denser towards distal segments. Dorsal furrow obsolete on all segments. Setation sparse, mostly represented by 5–8 dark macrosetae over every carina.

Telson ( Figs. 26). Sparsely setose, with a few setae scattered on dorsal and lateral surfaces. Vesicle elongate oval (2.50 times longer than wide, 0.95 times wider than deep), tegument smooth and glossy, with vestiges of coarse granules arranged into three obsolete longitudinal carinae (ventral median and ventral submedians), and ventrally with some coarse punctations. Subaculear tubercle absent. Aculeus conspicuously shorter than vesicle, thick and shallowly curved.

FEMALE (Chainury, Turkmenistan). Very similar to male, sexual dimorphism evident by: 1) size comparatively larger inside each size-class; 2) coloration darker and much more sharply patterned, e.g., pedipalp femur with a conspicuous blackish spot on dorsodistal apex, which diffusely continues as a broad stripe over almost all internal surface, patella with internal surface blackish, carapace with anterior margin deeply infuscate, metasomal segment V and telson black; 3) mesosoma and metasoma slightly less slender; 4) genital papillae absent; 5) pectines smaller, with consistently lower tooth counts; 6) metasomal segment V with lateral intercarinal tegument less granulose. See Figs. 6–7, 31–33 and Tabs. 1 , 4–5.

VARIATION. Adult size varied from 30.4–34.1 mm in males and 32.1–36.5 mm in females.

Pectinal tooth count varied as follows: 23–27 teeth in males and 20–23 in females, without clearly defined mode in either sex ( Tab. 5 ).

Males from Repetek are virtually identical to the holotype in all diagnostic characters. The only exception is that the tibial spurs are usually entirely absent. This character alone is inappropriate to separate both populations taxonomically, especially when only a single specimen from Tajikistan is available. In addition, the male from Tejen ( ZISP 809 ) has tibial spurs on both legs IV as noted already by Birula (1905: 450)

COMPARISON. Adults of A. rickmersi can be very easily distinguished by the greater slenderness of the metasoma, especially in males ( Figs. 1–2, 4–7, 117; Tabs. 1 , 4 ); even to unaided eye, most other congeners are more robust ( Figs. 34–45, 65–66, 79–82, 90–91, 107, 110, 113–114; Tabs. 2–4 ). For example, see the following male ratios: metasoma + telson length / carapace length = 7.76 vs. 6.26–7.14, metasomal segments length / width = 1.74 vs. 1.02–1.35 (I), 2.13 vs. 1.35–1.82 (II), 2.20 vs. 1.39–1.88 (III), 2.56 vs. 1.75–2.23 (IV) and 2.71 vs. 1.85–2.38 (V).

Moreover, this species is the only one that has metasomal segment V and telson light reddish-colored in adult males ( Figs. 1–2, 4–5, 23–25, 27–29, 117); in all other Anomalobuthus spp. , it is blackish, entirely or at least in its distal half ( Figs. 34–35, 38–39, 59–61, 79–80, 84–86).

DISTRIBUTION ( Fig. 141). Widespread in southern Central Asia, from the sands of the Karakum Desert (eastern Turkmenistan), to the loess soils of the Kyzylsu River valley (southwestern Tajikistan). See further details below, in Remarks section.

ECOLOGY. According to the personal data of the collector (Rickmer Rickmers, 1913: 442), the holotype was collected in early summer, from crevices or cracks of fine alluvial soil (“ loess crannies ”). Populations from the Karakum Desert inhabit sand dunes but tend not to occupy loose sands where two other sympatric ultrapsammophiles are found, Liobuthus kessleri and Pectinibuthus birulai Fet, 1984 . Detailed ecological information from Repetek was published by Fet (1980).

NOTES. The holotype of A. rickmersi remains the single specimen known from Tajikistan. Its collecting site was reported by Kraepelin (1900) as Bukhara (“Bucharei”, see the original museum label in Fig. 3) and interpreted by all subsequent authors as originating from the city, the capital of the homonymous Bukhara Khanate, located in modern Uzbekistan. In addition, Birula (1911b: 171) erroneously stated that the type specimen of A. rickmersi originated from “westlichen Buchara” (i.e. western part of the Bukhara Emirate).

This specimen was collected by the famous German mountain explorer Willi Rickmer Rickmers (1873–1965) who repeatedly visited the Bukhara Emirate , then a protectorate of the Russian Empire, which included part of modern Uzbekistan and Tajikistan ( Rickmer-Rickmers, 1899; Rickmer-Rickmers, 1913). During preparation of the present revision, we discovered that Rickmer Rickmers (1913: 442) himself actually published unequivocal information on the precise collection locality and date of the holotype, which we reproduce below verbatim :

By the way, the “poisonous spider” mentioned by the impressed collector is a solpugid, also described by Kraepelin (1899). It is a member of the Gylippidae family, currently regarded as a junior synonym of Gylippus ferganensis Birula, 1893 (see Harms & Dupérré, 2018). As all solpugids, it is indeed “vicious” but not “poisonous”.

Baljuan (also spelled Baldzhuan, now Baljuvon or Bal'dzhuvon) is a well-known town in modern Tajikistan, in the valley of Kyzylsu River, a tributary of the larger Panj River (= Pyandzh, Piandj), itself a tributary of the great Amudarya (the ancient Oxus). Baljuvon stands on the Silk Road, not far from the ancient Bactra (now Balkh in northern Afghanistan), and was last time noted as the place where Enver Pasha, a rival of the Turkish leader Mustafa Kemal (Ataturk), was killed in 1922 in a skirmish with the Soviet troops.

In more peaceful times, Rickmer-Rickmers (1899) published a map of his fourth travel to the Bukhara Emirate, conducted in 1898 (the 1896 trip was his third travel). We can see that he followed the same and (then) only route from Dushanbe (now the capital of Tajikistan) to Khovaling, via Baljuvon. Baljuvon lies very far to the southeast from the former Emirate's capital city of Bukhara (modern Uzbekistan) and is isolated by several mountain ranges from the lowland deserts of Uzbekistan.

Although quite active zoological research was conducted in Central Asia by numerous Russian (and then Soviet) researchers, very few scorpions have been collected in the remote valleys of northern tributaries of Amu Darya in modern Uzbekistan and Tajikistan. It is not surprising, therefore, that no other specimens of A. rickmersi have been collected in this area since 1896; in fact, no other scorpion collections we know of originate from Baljuvon. Moreover, another, much more amazing scorpion from the same area was not discovered until the 1990s: the relict Pseudochactas ovchinnikovi Gromov, 1998 (Pseudochactidae) . Its type locality lies in the Surkhandarya River valley, which separates modern Uzbekistan from Tajikistan ( Gromov, 1998; Fet et al., 2004).

The first known specimen from Turkmenistan (then the Transcaspian Region of the Russian Empire) was reported by Birula (1904: 32, 35). It was a female collected next to the railway station of Repetek in the East Karakum , the future site of the famed Repetek Natural Reserve , by the coleopterologist Eduard Nikolaevich Fischer in February 1904 ( ZISP 808 ). The second specimen was also published by Birula (1905: 449–450); it was a male from Tejen (= Tedzhen, Tedshen) in Akhal Province, collected by K. Aris in June 1904 ( ZISP 809 ). Further collections from Turkmenistan published by Fet (1989), included a series of more than 20 specimens from Repetek ( ZISP, ZMMSU). In addition, two males from Repetek are housed in NHMW and one in R. Kinzelbach's collection ( ZSRO). Some of these specimens are illustrated here in Figs. 4– 5, 27–30, 103–115. A few specimens from northern Turkmenistan (Kunya-Urgench, ZISP 1699 ; Shakhsenem, ZMMSU Tb-374), published by Fet (1989) as A. rickmersi , actually correspond to a different species ( A. pavlovskyi sp. n., see below) .

It is clear from A. Birula's publications that he never studied the holotype of A. rickmersi ; however, it was seen and its trichobothrial pattern sketched by Vachon (1974: 908, fig. 37). On the other hand, Lourenço (2001) claimed to have examined it; however, it is obvious that the specimen he received on loan from ZMUH was not Kraepelin's original holotype, but a misidentified and wrongly labeled juvenile of maybe even another genus. Lourenço (2001) declared this specimen as an immature with a total length of 13–14 mm [sic], pectinal tooth count 24–26, and textually wrote: “... cutting edge of the movable finger with 6 series of granules [...] the basalmost extending onto more than half the length of the finger. [... Pectinal] Fulcra almost vestigial and flat... ” [originally in French, English translation and bracketed text added by us].

None of these crucial characters match the holotype of A. rickmersi and clearly contradict the original description and illustrations published by Kraepelin (1900), which were confirmed by our own examination of the true type: it is a large adult male with a total length of 34 mm, pectinal tooth count 25/25, fingers with 10 rows of primary denticles of which the basal-most extends onto less than one-third of finger, and fulcra normally developed and pearl-like. Finally, a photo of the label of the specimen examined by Lourenço (2001), provided by himself to V.F.in 2009, does not correspond to any of those accompanying the actual holotype ( Fig. 3).

Tables

Table 1: Measurements of three adults of Anomalobuthus rickmersi. Abbreviations: length (L), width (W), posterior width (Wp), depth (D).

Dimensions (mm)		TJK, Baljuvon ♂ holotype (ZMUH)	TKM, Chainury ♀ (FKCP) ♀ (FKCP)
Carapace	L / Wp	3.05 / 3.80	3.67 / 4.30	3.55 / 4.03
Mesosoma	L	7.70	9.40	7.10
Tergite VII	L / W	2.15 / 3.50	2.35 / 4.10	1.79 / 4.18
Metasoma + Telson	L	23.38	23.41	21.48
Segment I	L / W / D	2.80 / 1.61 / 1.43	2.80 / 1.95 / 1.79	2.50 / 1.75 / 1.43
Segment II	L / W / D	3.40 / 1.60 / 1.58	3.48 / 1.78 / 1.85	3.00 / 1.63 / 1.58
Segment III	L / W / D	3.80 / 1.73 / 1.73	3.85 / 1.85 / 1.90	3.43 / 1.68 / 1.73
Segment IV	L / W / D	4.43 / 1.73 / 1.74	4.35 / 1.88 / 1.95	4.05 / 1.75 / 1.74
Segment V	L / W / D	4.55 / 1.68 / 1.50	4.78 / 1.97 / 1.72	4.45 / 1.78 / 1.50
Telson	L	4.40	4.15	4.05
Vesicle	L / W / D	2.63 / 1.05 / 1.10	2.65 / 1.40 / 1.30	2.60 / 1.30 / 1.20
Aculeus	L	1.77	1.50	1.45
Pedipalp	L	11.08	11.15	10.65
Femur	L / W	3.03 / 0.65	2.95 / 0.75	2.75 / 0.70
Patella	L / W	3.40 / 0.95	3.40 / 1.08	3.25 / 1.00
Chela	L	4.65	4.80	4.65
Manus	L / W / D	1.35 / 0.75 / 0.70	1.35 / 0.86 / 0.85	1.11 / 0.75 / 0.75
Movable finger	L	3.30	3.45	3.54
Total	L	34.13	36.48	32.13