Two new Chaerilus from Thailand and Laos (Scorpiones: Chaerilidae) Author Kovařík, František Author Lowe, Graeme Author Stockmann, Mark Author Šťáhlavský, František text Euscorpius 2020 324 1 20 journal article 6629 10.5281/zenodo.4648882 b6d642ba-67fa-4991-bf5d-5583e71f9896 1536-9307 4648882 DB1216AA-360D-4FC6-BA4C-13D3B032B359 Chaerilus kautti sp . n . ( Figures 1–50 , 84 , Table 1 ) http://zoobank.org/urn:lsid:zoobank.org:act:8275997C- 69A8-4494-A6F1-ED502A69E1FF TYPE LOCALITY AND TYPE REPOSITORY . Thailand , Prachuap Khiri Khan Province , Khao Ma Rong Cave , 11.2021900°N 99.4946250°E , 56 m a. s. l. , FKCP . TYPE MATERIAL ( FKCP ). Thailand , Prachuap Khiri Khan Province , Khao Ma Rong Cave , 11.2021900°N 99.4946250°E , 56 m a. s. l. ( Fig. 48 ), 19.VIII.2018 , 1♂ ( holotYpe , 1770 , Figs. 1 , 3–4 , 7–8 , 15, 20–32 , 44–47 ), leg. Peter Kautt , 1♀ ( paratYpe , Figs. 2 , 5–6 , 9–14 , 16–19 , 33– 43 , 49–50 , scorpion born 27.IX.2020 ), leg. Britta & Mark Stockmann , 16 juvs. ( paratYpes , Figs. 49–50 , offspring of the female paratYpe 27.IX.2020 , still alive), bred bY F. Kovařík and M. Stockmann . ETYMOLOGY. The specific epithet is a patronYm honoring Peter Kautt, the collector of the male holotYpe of the new species. DIAGNOSIS ( ♂ ♀ ). Total length 37–43 mm ; two pairs of lateral eYes and one pair of median eYes; ventral surface of cheliceral fixed finger with 4 denticles; male differs from female in having pedipalp chela much narrower; chela length/width ratio ♂ 4.55, ♀ 2.88; movable finger of pedipalp with 11 imbricated rows of granules; fingers straight in both sexes; pedipalp chela with 7–8 carinae; pectinal tooth count ♂ 6, ♀ 4; carapace granulated sparselY in male, denselY in female; mesosomal tergites granulated, mainlY in the female; all sternites smooth without carinae and granules; metasoma I–III with 6 or 8 carinae, ventral carinae maY be absent. DESCRIPTION. Total length ♂ 37 mm , ♀ 43 mm ; color reddish orange to brown, maculose; chelicerae ( Figs. 42–43 ) sparselY granulated dorsallY, Yellow and stronglY reticulate, anteriorlY black; male differs from female in having pedipalp chela much narrower with short fingers; chela length/width ratio ♂ 4.55, ♀ 2.88; male with larger pectines ( Figs. 8 and 10 ); no sexual dimorphism in shape of metasoma and telson; trichobothrial pattern as shown in Figs. 23–29 , measurements in Table 1 . Carapace and mesosoma ( Figs. 7–10 ). Carapace covered bY large granules in female, almost smooth in male; anterior margin of carapace weaklY concave; two well developed pairs of lateral eYes and one pair of median eYes present; mesosomal tergites irregularlY granulated in female, almost smooth in male; all sternites smooth without carinae and granulation; sternite V with smooth patch present; pectinal tooth count ♂ 6, ♀ 4. Metasoma and telson ( Figs. 15–22 ). Metasoma I–II with 6 or 8 incomplete carinae, ventral carinae reduced or absent; metasoma IV with 8 carinae, metasoma V with 5 carinae; all carinae composed of sparse, large granules; intercarinal surfaces sparselY, irregularlY granulated, more so on lateral surfaces of all segments, and ventral surfaces of segment V; metasomal segments I–III ventrallY smooth; all segments verY sparselY hirsute; telson elongate, ampullate, smooth, verY sparselY hirsute. Pedipalps ( Figs. 23–41 ). Pedipalp chela elongated in male, rather stout in female; movable finger with 11 and fixed finger with 10 imbricated rows of granules; chela with 7 or 8 carinae, smooth in male, partlY finelY granulated in female; carina on dorsoexternal surface of the manus maY be incomplete; dorsal and internal surfaces of chela with reticulate granulation patterns; patella with 5–6 smooth carinae, surfaces of patella smooth except internal surface which is finelY granulated; femur denselY granulated with 4 carinae. Legs ( Figs. 11–14 ). Hirsute, without bristlecombs and carinae; femora and patellae granulated dorsallY, other surfaces smooth; tarsomeres with 4 rows of spiniform setae; spiniform seta formula of inner rows 6–7/7–8: 7–8/6–7: 7–8/8–9: 6–8/8–9; of outer rows 3–4/3–4 on all legs. Hemispermatophore ( Figs. 44–47 ). Fusiform; distal lamina short, broad, weaklY tapered, apex rounded; capsule with distal carina weaklY sclerotized; sperm hemiduct delineated bY two thin, sclerotized carinae, of which the distal is longer, the basal shorter; trunk long, as broad as capsule. Measurements of right hemispermatophore (mm): distal lamina length 0.64, capsule length 0.72, trunk length 1.96, pedicel length 0.42, capsule width 0.63. Left hemispermatophore with shorter trunk, length 1.70. Karyotype ( Fig. 84 ). Male holotYpe was analYzed. During metaphase I 59 bivalents were observed ( Fig. 84 ), implYing that 2n=118. Chiasmata were not observed during meiosis. AFFINITIES. Chaerilus kautti sp . n . is reliablY distinguished from all other Chaerilus species bY the following unique combination of two characters: movable pedipalp finger with 11 imbricated granule rows; and pedipalp chela length/width ratio 4.55 in the male. A movable pedipalp finger with 11 (or 10–11) imbricated granule rows is also found in six other species of the genus ( C. cimrmani Kovařík, 2012 from Thailand , C. hofereki Kovařík, 2014 from Vietnam , C. julietteae Lourenço, 2011 from Vietnam , C. neradorum Kovařík et al., 2018 from Thailand , C. robinsoni Hirst, 1911 from MalaYsia and Indonesia , and C. stockmannorum Kovařík et al., 2018 from Thailand ). However, males of all of these species have a pedipalp chela length/width ratio between 1.84 ( C. hofereki ) and 3.13 ( C. julietteae ). Figures 3–6 : Chaerilus kautti sp . n . Figures 3–4 . HolotYpe male, dorsal (3) and ventral (4) views. Figures 5–6 . ParatYpe female, dorsal (5) and ventral (6) views. Scale bar: 10 mm. Figures 7–14 : Chaerilus kautti sp . n . Figures 7–8 . HolotYpe male, carapace and tergites I–III (7), and sternopectinal region and sternites (8). Figures 9–14 . ParatYpe female, carapace and tergites I–II (9), sternopectinal region and sternites (10), left legs I–IV, retrolateral aspect (11–14). Figures 15–22 : Chaerilus kautti sp . n . Figures 15 , 20–22 . HolotYpe male, telson lateral (15), metasoma and telson, lateral (20), ventral (21), and dorsal (22) views. Figures 16–19 . ParatYpe female, telson lateral (16), metasoma and telson, lateral (17), ventral (18), and dorsal (19) views. Scale bars: 10 mm (17–19, 20–22). Figures 23–32 . Chaerilus kautti sp . n . , holotYpe male, pedipalp chela, dorsal (23), externodorsal (24), and ventrointernal (25) views. Pedipalp patella, dorsal (26), external (27) and ventrointernal (28) views. Pedipalp femur and trochanter, dorsalointernal (29) and ventral (30) views. Movable (31) and fixed (32) fingers dentition. The trichobothrial pattern is indicated in Figures 23–29. Figures 33–41 . Chaerilus kautti sp . n . , paratYpe female, pedipalp chela, dorsal (33), external (34), and ventrointernal (35) views. Pedipalp patella, dorsal (36), external (37) and ventral (38) views. Pedipalp femur and trochanter, dorsalointernal (39) and ventral (40) views. Movable finger (41) dentition. Figures 42–43 . Chaerilus kautti sp . n . , paratYpe female, left chelicera dorsal (42) and ventral (43) views. COMMENTS ON LOCALITIES AND LIFE STRATEGY. The tYpe localitY is located on an isolated karst mountain close to the eastern coast of Thailand , west of Bang Saphan. The entire mountain is clothed in primarY forest, but is surrounded bY cultivated farmland with mostlY oil palms and gumtrees. The tYpe localitY is close to two extensive caves, but C. kautti sp . n . does not appear to be associated with them. Climate conditions are warm and verY wet during the wet season from MaY to November, and slightlY cooler and drier during the drY season from December to April. Even during the drY season, the area is verY humid and water is alwaYs present. The male from 2018 was collected during heavY rain on a dark night, the female from 2019 on a drY night without wind during a new moon. The average temperatures on both nights were ca. 25–26°C with verY high humiditY. Figures 44–48 : Chaerilus kautti sp . n . Figures 44–47 . Hemispermatophores of holotYpe. Figures 44–45 . Right hemispermatophore, posterior (44) and convex (45) views. Figure 46 . Left hemispermatophore, convex view. Note: the fissure in the sperm hemiduct is damage from handling, not a natural feature. Figure 47 . Right hemispermatophore, capsule and distal lamina, convex view, fine refractile structure visualized under Nomarksi illumination. Scale bars: 1 mm (44–46), 500 μm (47). Figure 48 . TYpe localitY. Figures 49–50 . Chaerilus kautti sp . n . , paratYpe female with newborns (40) and with juveniles after first ecdYsis (50) in vivo habitus.

C. kautti sp . n .	C. kautti sp . n .	C. pulcherrimus sp . n .	C. pulcherrimus sp . n .
Dimensions (mm)	♂ holotype	♀ paratype	♂ holotype	♀ paratype
Carapace	L / W	5.69 / 5.71	5.23 / 5.68	2.96 / 3.01	2.79 / 2.70
Mesosoma	L	8.81	18.20	4.40	4.10
Tergite VII	L / W	2.05 / 4.38	2.65 / 4.75	1.38 / 2.40	1.13 / 2.32
Metasoma + telson	L	23.03	19.18	11.44	9.50
Segment I	L / W / D	2.28 / 2.87 / 2.20	1.97 / 2.84 / 2.11	1.13 / 1.78 / 1.27	0.90 / 1.20 / 1.00
Segment II	L / W / D	2.67 / 2.36 / 2.20	2.25 / 2.41 / 1.74	1.31 / 1.51 / 1.17	1.04 / 1.16 / 0.88
Segment III	L / W / D	2.82 / 2.29 / 2.13	2.16 / 2.23 / 1.69	1.40 / 1.29 / 1.10	1.12 / 1.09 / 0.95
Segment IV	L / W / D	3.21 / 2.27 / 1.89	2.45 / 2.01 / 1.63	1.48 / 1.29 / 1.17	1.28 / 1.05 / 0.86
Segment V	L / W / D	5.72 / 2.18 / 1.94	4.77 / 1.88 / 1.63	2.61 / 1.29 / 1.15	2.22 / 1.10 / 0.92
Telson	L / W / D	6.33 / 2.20 / 2.19	5.58 / 2.12 / 1.98	3.51 / 1.36 / 1.28	2.94 / 1.34 / 1.04
Pedipalp	L	28.70	19.43	10.05	8.56
Femur	L / W	7.05 / 2.14	4.49 / 1.93	2.32 / 1.04	2.02 / 0.94
Patella	L / W	7.45 / 2.18	4.86 / 2.24	2.62 / 1.24	2.15 / 1.02
Chela	L	14.20	10.08	5.11	4.39
Manus	W / D	3.12 / 3.44	3.50 / 3.29	1.99 / 2.10	1.63 / 1.75
Movable finger	L	5.11	5.40	2.36	2.29
Total	L	37.53	42.61	18.80	16.39

Table 1 . Comparative measurements of adults of Chaerilus kautti sp . n . and C. pulcherrimus . Abbreviations: length (L), width (W, in carapace it corresponds to posterior width), depth (D). Both specimens were found at night on the ground, between leaf litter or sitting openlY on rocks. In captivitY, the scorpions concealed themselves under bark or in moss. The probablY do not excavate burrows, but instead shelter between rocks, or in wood and leaf litter in their habitat. Other scorpions observed in this habitat were Heterometrus cimrmani Kovařík, 2004 , Lychas scutilus Koch 1845 , and Liocheles australasiae Fabricius, 1775 . An adult gravid female collected in 2019 gave birth in captivitY to 48 juveniles after 11 months.