Scorpiops tongtongi Tang, 2022

Tang, Victoria, 2023, Description of the adult male Scorpiops tongtongi Tang, 2022, with further comments on the genus Scorpiops Peters, 1861 in China (Scorpiones: Scorpiopidae), Euscorpius 377, pp. 1-52 : 2-20

Scorpiops tongtongi Tang, 2022

( Figures 1–56 , 96 , 113–116 ; Tables 1–3) http://zoobank.org/urn:lsid:zoobank.org:act:7A317530-

A04C-48E8-8061-B99958D3DED6

TYPE LOCALITY AND TYPE DEPOSITORY. Holotype ♀, China, Yunnan Province, Dehong Prefecture , Yingjiang County, 24°37'39''N 97°38'27''E, 1451 m a. s. l; VT.

NEW MATERIAL EXAMINED. China, Yunnan Province, Dehong Prefecture, Yingjiang County, near Chashanzhai , 24°37'07''N 97°39'11''E (24.618553°N 97.652983°E), 1380 m a. s. l., 19 June 2023, 1♂ (alive when received; Fig. 55 ), near Rongshuwang, 24°40'18''N 97°36'20''E (24.671558°N 97.605458°E), 950 m a. s. l., 10 July 2023, 1♂ 3♀ (dead when received; Fig. 96 ), leg. Chenkai Tang; VT .

DIAGNOSIS (modified from Tang, 2022b). Total length ca. 40–45 mm for females and 44 mm for male. Base color uniformly reddish brown to brownish black, telson and parts of legs brown to brownish yellow. Pectinal teeth number 5–6 in females and 7 in males; fulcra absent; pectines form one compact unit with an incomplete furrow between areas where marginal and middle lamellae are usually delimited. Patella of pedipalp with 17–18 external and 6–7 ventral trichobothria. Chela with 4 V series trichobothria located on ventral surface. Chelal trichobothrium Eb 3 located in middle of manus between trichobothria Dt and Est. Dentate margin of movable fingers of pedipalps not obviously undulate (no proximal lobe present) in female but strongly undulate in male (proximal lobe present) and create prominent gap when closed (in combination with the strong ventral incision on dentate margin of fixed finger). Chela length to width ratio 2.9–3.17 in females and 2.71–2.91 in males. Pedipalp movable finger with ca. 39–52 IAD, which have the same size as MD (ca. 86–96 in number) and create a second row of denticles; there are also 3–5 ID and 10–12 OD present. Tarsomere II of leg III with 5–9 stout median ventral spinules in a single row, and two pairs of flanking setae. Metasoma I with 10 carinae, II– IV with 8 carinae, V with 7 carinae. Telson relatively short and bulbous, and densely covered with fine granules, length to depth ratio 2.8–3.4 in females and 2.63–2.84 in males; annular ring developed (circumference constricted at vesicle-aculeus juncture).

DESCRIPTION (of adult male). The hereby description of adult male S. tongtongi ( Figs. 1–2 ) is modified from the original description for the holotype female, with coloration disregarded. Both white light and UV light (except for the overall habitus) photos are provided. Figures of pectines, trichobothria and finger dentitions of the females, the living male and the left pedipalp patella of the dead male are available on ResearchGate as supplementary files (in ZIP.).

Prosoma and mesosoma ( Figs. 3–12 , 31–34 ). Prosoma: Carapace with 3 pairs of lateral eyes of which two are larger and one is smaller. Superciliary carinae of the median ocelli smooth, short and compact, closely spaced. Median dorsal part of the carapace (ca. half of total area) planar, from anterior to posterior margins; lateral surfaces slanting downwards. Lateral surfaces with a pair of shallow central lateral sulci and prominent posterior lateral sulci; posterior marginal sulcus obvious. Entire carapace generally smooth, sparsely covered with small to moderate sized granules; distinct carinae absent. Anterior margin of carapace with a prominent median notch (emargination) leading to a deep, wide, smooth anteromedian sulcus. Circumocular sulcus is connected with anteromedian sulcus anteriorly, and with posteromedian sulcus posteriorly. Larger granules concentrated at edges flanking anteromedian sulcus, and above and posterior to lateral ocelli. Chelicerae with dorsal surface smooth and ventral surface setose; macrosetae localized on fixed finger. Dorsal distal, ventral distal and distal denticles of cheliceral fingers very long. Mesosoma: tergites sparsely covered with smaller to moderate granules, becoming slightly denser and larger closer to posterior margins, with one very weak median carina indicated (concealed by random granules on VII). Tergite VII pentacarinate. Sternites smooth with sparse macrosetae and fluorescent microsetae; sternites IV–VI with two axisymmetric, curved furrows furnished with lattice microstructure (shattered on VII), sternite VII with four weakly granulate carinae; respiratory spiracles suboval. Genital operculum divided into two halves, with a pair of genital papillae at the base. Pectines form one compact unit with incomplete furrow between areas where marginal and middle lamellae are usually delimited; pectine teeth number 7; area of peg sensilla with cover the majority of each pectinal tooth; fulcra absent; fluorescent microsetae stout.

Metasoma and telson ( Figs. 39–46 ). Metasoma sparsely hirsute and granulated; carinae with relatively large granules. Metasomal segment I with 10 carinae, II–IV with 8 carinae, and V with 7 carinae. Median lateral carina of metasoma II–IV incomplete, presented by several posterior granules. Granules relatively smaller and thinner on dorsosubmedian (I–IV), median lateral (V) and dorsolateral (V) carinae, larger and rounded on dorsolateral (I–IV), median lateral (I), ventrolateral (I–III) and ventrosubmedian (I–III) carinae. becoming conspicuously sharper on ventrolateral (IV–V), ventrosubmedian (IV) and ventromedian carinae (V). Anal arch armed with sharp granules. Telson proportionally short and bulbous; dorsal surface smooth, lateral and ventral surfaces with dense, fine granulation; annular ring developed. Vesicle sparsely covered with fluorescent microsetae and few macrosetae; lateral surface with one longitudinal sulci close to dorsal surface, ventral surface with two parallel longitudinal sulci, all four sulci shallow and basically smooth (covered with extremely minute granules). Aculeus smooth, weakly curved (tip broken).

Pedipalps ( Figs. 13–30 , 35–38 ). Pedipalps sparsely hirsute, intercarinal surfaces scattered with small to moderate granules and patches of squamous/lattice microstructures; fluorescent microsetae show weak iridescence under white light, visible under high magnification. Patella with 17–18 external (4–5 et, 4 est, 2 em, 2 esb, 5 eb) and 6–7 ventral trichobothria. Chela with 4 V series trichobothria located on ventral surface. Chelal trichobothrium Eb 3 located in middle of manus between trichobothria Dt and Est. Femur and patella granulated. Femur with 6 granulose carinae; promedian carina incomplete, composed of several large, discrete granules; retroventral carina incomplete, deconstructed into small, random granules; granules larger on prodorsal, retrodorsal, retromedian and proventral carinae, especially the retromedian carina. Patella with 5 granulose carinae, composed of large granules; granules larger and denser on retrodorsal, retromedian and retroventral carinae, discrete on prodorsal and proventral carinae; prolateral surface with two small internal apophyses. Manus dorsally with fine, rounded granules; largest granules constitute digital, dorsal marginal and ventromedian carinae; moderate size granules present on interomedian carina; subdigital, dorsal secondary, dorsal internal, ventrointernal, ventroexternal, and external secondary carinae relatively weak, incomplete or obsolete, gradually diffusing to dispersed granules. Dentate margin of movable fingers strongly undulate (proximal lobe present) and create prominent gap when closed (in combination with the strong ventral incision on dentate margin of fixed finger). Movable fingers (left/right) with 52/49 IAD, which have the same size as MD (96/ 91 in number) and form a second row that terminated at the proximity of lobe; 4/4 ID and 12/11 OD also present, larger than IAD and MD.

Legs ( Figs. 47–54 ). Tibia and tarsomeres of legs with several macrosetae and fluorescent microsetae not arranged into bristle combs. Basitarsi of legs I–II with two rows of short spinules, a pair of pedal spurs present on basitarsi of all legs. Telotarsi of legs I–IV with a row of short, stout ventromedian spinules that has 2 spinules on both ends and 2–5 spinules in the middle (i.e., 6–9 in total). Ungues moderately long and curved. Femur with 3–4 and patella 4–5 carinae; both femur and patella finely granulated, with sparse setae.

Hemispermatophores ( Figs. 56–60 ). Lamelliform in profile. Distal lamina long, moderately slender; basally constricted, terminally coiled and tapered. Capsule conforms to 2-folds bauplan; distal posterior lobe marginally sclerotized and armed with ca. 9 denticles; lateral hook entirely sclerotized, apically sharpened; terminal membrane of sperm duct spiculate and translucent; basal carina accords with Group 4 ( Kovařík et al., 2020: 27), sclerotized and distally expended into a plate with polydentate basal crest bearing crown-like structure. Trunk broad with mid-axial rib dividing it into anterior and posterior halves, distal end of the axial rib connected to the sclerotized distal carina of the capsule by a narrow junction, truncal flexure absent. Pedicel (= foot, in Kovařík et al., 2020) broad, soft and translucent.

Measurements. See Table 1.

VARIATION. Both males had 7 teeth on each pectine. The examined dead male had one additional trichobothrium in the et series and one absent trichobothrium in the V series on its left pedipalp patella. The living male had 17 external and 7 ventral trichobothria on both of its patellae, identical with the right pedipalp of the dead male. The 11 th OD (on its right movable finger) of the dead male nearly fitted into the MD series but was recognized by the prominent gap it created between two adjacent MDs. Living male with 10/10 OD, 86/89 MD, 50/50 IAD, and 5/5 ID on its left/right movable fingers; right movable finger with one additional enlarged “IAD” (excluded) between the first IAD and third ID.

NOTE. In the original description, Tang (2022b: 5, 10, fig. 11) considered fulcra to be present in the holotype female. However, based on the current inspection of new materials with improved photographic technologies, it is now confirmed that S. tongtongi does lack fulcra. The triangular interdental membrane was mistaken as the fulcrum in the original description, which also appeared fluorescent under UV light. Ambiguous figures in the past literature and contradiction between statements in the papers published by other authors and personal observations also led Tang (2022b: 21, 34, 40) to believe that it is uncertain whether there are Scorpiops species that lack fulcra. Later, Lv & Di (2022: figs. 11, 13, 43, 45, 75, 77) well illustrated the pectine morphology of three Tibetan congeners which S. tibetanus Hirst, 1911 clearly differed from S. atomatus Qi et al., 2005 and S. lourencoi Lv & Di, 2022 by the lack of pectinal fulcra.

SEXUAL DIMORPHISM. The three new females were examined in terms of their chela-L/W, telson L/D, PTC, trichobothria and finger dentition. Ratiometrics of chela and telson are incorporated in the diagnosis and Table 2. In one single female, only five teeth were observed on its left pectine (“left/right” considered as in ventral view). All three examined females had 17 external and 7 ventral trichobothria on either of their patellae. Geometric configurations of patellar trichobothria generally the same among all examined materials, except that there was a higher variability in the relative position of em and esb series where the distal esb may travel to the same level of em. The males of S. tongtongi can be easily distinguished from the females by the presence of the proximal lobe on pedipalp movable finger (and a corresponding notch on fixed finger) and a pair of genital papillae at the base of the genital operculum. Pectines of males proportionally longer with longer and larger teeth, adorned with more peg sensilla (sensory area located on distal region in females). In addition, tergal granules are larger and slightly denser in females; this discrepancy appears to exhibit in most Yunnan Scorpiops (except for S. jendeki where male has apparently denser granulation) and may probably be related to parental care behavior in which females have to provide a more grippable surface for the offspring.

It is also interesting to note that there was a consistent sexual dimorphism in the denticle rows on movable finger. All movable fingers of examined females exhibited the same condition as in the holotype female: IADs did not evidently partition from MDs when they approached proximity of the finger, and random series of denticles continued the entire length of dentate margin. The same method for differentiating MD and IAD was applied: the most proximal IAD was recognized as the one on the same level with the most proximal OD, treating all the more proximal denticles as MDs. This decision was taken as the most proximal OD located near the region where the IADs terminate in males. On the other hand, IADs terminated in the proximal end of the finger lobe in males, and a single row of MDs covered a small section before it again proliferated into random distributions. Given the location where the single row was recognized, this variation may result from the presence of the proximal lobe in males. However, this discrepancy did not give rise to prominent sexual dimorphism in denticle counts. Values (left/right) for three examined females: (1) 10/10 OD, 86/97 MD, 46/46 IAD, 1/≈2 ID; (2) 10/10 OD,>73/>86 MD, 39/40 IAD, 3/3 ID; (3) 11/11 OD, 86/92 MD, 45/42 IAD, 4/4 ID. In the first female, only one ID was identifiable on its left finger, while on its right finger, proliferations were discovered at the distal region, confusing the separation of ID and IAD as well as yielding higher count of MD; this is thus considered abnormal and excluded from the diagnosis. In the second female, the proximal region on both of its fingers was damaged, rendering low count of MD (excluded). Other characters generally the same, except for the chela which is relatively more robust in males.

AFFINITIES. The described features of the adult male further differ S. tongtongi from all its Yunnan congeners and will be elaborated below. Tang (2022b: 14) also compared it from a geographically closest neighbor from Myanmar, S. beccaloniae ( Kovařík, 2005) . While S. tongtongi was described by a single female specimen, S. beccaloniae was based on a male. This thus undermined the credibility of the validity of S. tongtongi if the two species were to be compared. However, the author nonetheless applied two sex-independent characters to support her statement: ventral patellar trichobothria number and spiniform apophysis of patella. Other characters either were the same or may show substantial overlap in this genus. With the current description of adult male S. tongtongi , it is now certain that both species are indeed different. S. beccaloniae is more similar to other Yunnan Scorpiops (except for S. jendeki ) by its dark coloration, proportionally larger median ocelli, triangular anteromedian notch of carapace, proportionally narrower pedipalp chela, strong patellar spiniform apophysis, rough cuticle and elongated telson ( Kovařík, 2005: figs. 13–14). S. beccaloniae also has a higher PTC range (8–9) while both males of S. tongtongi are 7. Based on the knowledge of Yunnan Scorpiops , if the overall range is 7–9, then encountering specimens with 8 PTC would be of a much higher possibility (e.g., male S. vachoni : frequency of 7 PTC ≈ 0.06, frequency of 8 PTC ≈ 0.85, frequency of 9 PTC ≈ 0.09, n = 34).

ECOLOGY AND BEHAVIOR. Specimens of S. tongtongi were found sympatrically with S. zhangshuyuani in Tongbiguan

Township, in a landscape featuring chains of undulating hills. The microhabitat of S. tongtongi is characterized by rocks and soils covered with green, short mosses, and they were often found under rocks and rotten logs. Young juveniles (approximately 3~4 instar) were found during the same period (June to July) as subadults and adults. Anecdotal observations reported the occurrence of subadult and adult S. tongtongi since March, where some individuals were running on the ground diurnally. Two gravid females examined were dissected with 18 and 22 embryos respectively. This species also appears to have a higher demand for humidity than other Yunnan Scorpiops .

The scorpions showed temporary resistance towards conspecifics shortly after they were captured and placed in small containers. However, a case of cannibalism was reported by the collector where an immature individual was consumed by an adult female. Under captive condition, the single adult male exhibited different temperaments with respect to most of the other Yunnan congeners. For example, in comparison with the adult male S. xui which remained almost motionless when being touched, the adult male S. tongtongi inclined to flee in response to the tactile stimulation. The two species also showed different sensitivities to vibrations caused by the movement of their containers: S. xui appeared to be indifferent while S. tongtongi was agitated, constantly moving back and forth, seemed to be deciding the direction of its subsequent escape path.

Furthermore, comparing with the congeners with relatively longer pedipalps, S. tongtongi may instead resort to thumping the threat with pedipalps more frequently, similar to the behavior observed in some Heterometrus with robust pedipalp chelae ( Tang, 2023) and S. langxian from Tibet (Tang, pers. obs.). It also wielded its telson more frequently than the congeners. Thanatosis or catalepsy was less easily to be triggered as the scorpions usually tended to fight back or escape when being threatened. However, under particular scenarios, they do manifest a similar posture as observed in Tityus ocelote Francke & Stockwell, 1987 and Ananteris platnicki Lourenço, 1993 ( Triana et al., 2022: figs 2a, c). This usually happens after the scorpion was rapidly flipped or dropped. It is also worth noting that all of the examined Yunnan Scorpiops had been observed with cataleptic behaviors (e.g., Fig. 60 ). Similar behavior was also observed in Chaerilus conchiformus Zhu et al., 2008 (a single adult male) and C. pseudoconchiformus Yin et al., 2015 (a pair of adults) collected from Bayi District, Nyingchi, Tibet (Tang, pers. obs.).

Figures

Figures 1–2. Scorpiops tongtongi, male, habitus in dorsal (1) and ventral (2) views, under white light. Scale bar = 10 mm.

Figures 3–4. Scorpiops tongtongi, male, prosoma and mesosoma in dorsal view, under white (3) and UV (4) light. Scale bar = 10 mm.

Figures 5–6. Scorpiops tongtongi, male, prosoma and mesosoma in ventral view, under white (5) and UV (6) light. Scale bar = 10 mm.

Figures 7–12. Scorpiops tongtongi, male, carapace (7, 10), pectines (8, 11) and sternites VI–VII (9, 12). Figures 7–9. Under white light. Figures 10–12. Under UV light.

Figures 13–21. Scorpiops tongtongi, male, pedipalp chela in dorsal (13), external (14) and ventral (15) views, patella in dorsal (16), external (17) and ventral (18) views, femur in dorsal (19), external (20) and ventral (21) views, under white light. Scale bar = 10 mm.

Figures 22–30. Scorpiops tongtongi, male, pedipalp chela in dorsal (22), external (23) and ventral (24) views, patella in dorsal (25), external (26) and ventral (27) views, femur in dorsal (28), external (29) and ventral (30) views, under UV light. Trichobothrial pattern indicated in Figures 22–28. Carina abbreviations: d = digital, sd = subdigital, ds = dorsal secondary, dm = dorsal marginal, di = dorsal internal, im = interomedian, vi = ventrointernal, vm = ventromedian, ve = ventroexternal, es = external secondary, pd = prodorsal, rd = retrodorsal, rm = retromedian, rv = retroventral, pv = proventral, pm = promedian. sa = spiniform apophysis.

Figures 31–38. Scorpiops tongtongi, male. Figures 31–34. Dorsal (31, 33) and ventral (32, 34) views of left chelicera in opening status (right chelicera in closing status available in original description) under white (31–32) and UV (33–34) light. Figures 35–38. Left movable finger (35, 37), right movable finger (36, 38), under white (35–36) and UV (37–38) light. Finger dentition indicated in Figures 37–38. Denticle abbreviations: dd = dorsal distal, vd = ventral distal, d = distal, sd = subdistal, m = median, b = basal, va = ventral accessory. Scale bar = 2 mm (31–34) and 3 mm (35–38).

Figures 39–46. Scorpiops tongtongi, male, metasoma and telson in dorsal (39, 42), lateral (40, 43) and ventral (41, 44) views, telson in lateral view (45, 46). Figures 39–41, 45. Under white light. Figures 42–44, 46. Under UV light. Carina abbreviations: dsm = dorsosubmedian, dl =

Figures 47–54. Scorpiops tongtongi, male, left legs I–IV in retrolateral view. Figures 47–50. Under white light. Figures 51–54. Under UV light. Scale bar = 2 mm

Figures 55–60. Scorpiops tongtongi, male and left hemispermatophore. Figure 55. Male in vivo habitus under captive condition.Figures 56–60. Left hemispermatophore in convex view (56). Capsule in convex (57, 59) and concave (58, 60) views. Capsule exposed in air (59–60) was coated with clove oil in order to reveal the surface texture before the photos were taken.Abbreviations: dpl (distal posterior lobe), lh (lateral hook), tmsd (terminal membrane of sperm duct), bc (basal carina), bcr (basal crest), cls (crown-like structure), mar (mid-axial rib), dc (distal carina).

Figures 93–96. Application of “condyle method” upon a modified caliper (93–95) using the right chela of an adult male S. xui as the example, and pinned specimens of S. tongtongi (96). In reality, to avoid the deviation caused by the curvature of chelal fingers, the chela needs to be positioned in a vertical direction (Fig. 94); this obviously depends on the width of the L-shaped plate. The chela does not have to be orthogonal to a horizontal plane since the rotation around the pitch axis does not affect the width measured, as long as the roll and yaw axes are fixed (thus defining a 2D plane) based on the rod (however, this could be difficult by manual measurement).

Figures 97–136. Comparison of adult Yunnan Scorpiops chelae under white light. Figures 97–100. S. jendeki Kovařík, 1994, male (97, 98) and female (99, 100). Figures 101–104. S. lowei Tang, 2022, male (101, 102) and female (103, 104). Figures 105–108. S. puerensis (Di et al., 2010), male (105, 106) and female (107, 108). Figures 109–112. S. shidian (Qi et al., 2005), male (109, 110) and female (111, 112). Figures 113–116. S. tongtongi Tang, 2022, male (113, 114) and female (115, 116). Figures 117–120. S. vachoni (Qi et al., 2005), male (117, 118) and female (119, 120). Figures 121–124. S. validus (Di et al., 2010), male (121, 122) and female (123, 124). Figures 125–128. S. xui (Sun & Zhu, 2010), male (125, 126) and female (127, 128). Figures 129–132. S. yangi (Zhu et al., 2007), male (129, 130) and female (131, 132). Figures 133–136. S. zhangshuyuani (Ythier, 2019), male (133, 134) and female (135, 136).