Scorpiops (Euscorpiops) doiphukha, Ythier & Košulič & Nawanetiwong & Lourenço, 2025

Ythier, Eric, Košulič, Ondřej, Nawanetiwong, Wasin & Lourenço, Wilson R., 2025, A newly discovered species of the genus Scorpiops Peters, 1861, subgenus Euscorpiops Vachon, 1980 from Doi Phu Kha National Park, Thailand (Scorpiones, Scorpiopidae), ZooKeys 1241, pp. 171-184 : 171-184

Scorpiops (Euscorpiops) doiphukha sp. nov.

Figs 1 , 2 , 3 , 4

Type material.

Thailand • Nan Province, Doi Phu Kha National Park , GPS 19°11'53"N, 101°5'6"E, ca. 1400 m a. s. l., hill evergreen forest, 28/V/2024 (O. Košulič leg.). • Adult male holotype , 2 adult females (one incomplete), 2 pre-adult males, 3 juvenile females and 4 juvenile males paratypes . Adult male holotype, one adult female (complete) paratype and one pre-adult male paratype are deposited in Muséum national d’Histoire naturelle, Paris, France. Other paratypes are deposited at Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.

Etymology.

The specific name refers to the National Park of Doi Phu Kha where the new species was collected.

Diagnosis.

The new species exhibits the general characteristics of the subgenus Euscorpiops ( Vachon 1980; Soleglad and Sissom 2001). Male holotype and female paratype with respectively 70.3 and 63.3 mm in total length, defining the new species as large in relation to most other species of the genus. General coloration yellowish brown (female) to reddish brown (male). Pectines with 8–8 teeth in male, 7–7 teeth in female; two marginal and one middle lamellae present; fulcra present in adult specimens. Annular ring conspicuous in both sexes; telson length / depth ratio 2.92 in male, 3.82 in female. Sexual dimorphism strongly marked with male pedipalps markedly elongated; chela length / width ratio 5.35 in male, 3.95 in female. Chela fingers undulate in both sexes; movable fingers with two parallel longitudinal rows of granules almost fused, formed by a row of about 97 median granules and a row of about 72 inner accessory granules; 3–4 inner granules and 13–15 outer granules are also present. Trichobothriotaxy of type C ( Vachon 1974, 1980); three trichobothria on femur (dorsal, internal, and external); patella with 2 dorsal, 1 internal, 11–12 ventral and 18 external trichobothria; chelal manus with 4 ventral, 2 dorsal (Dt, Db), 2 internal (ib, it), 1 Est, 5 Et, 1 Esb and 3 trichobothria in the Eb series; trichobothrium Eb 3 located in distal half of manus, between trichobothria Dt and Est.

Description.

Based on male holotype and one female paratype.

Coloration (in alcohol).

Basically, yellowish brown (female) to reddish brown (male). Carapace yellowish brown (female) to reddish brown (male) with paler zones posteriorly and on furrows. Tergites yellowish (female) to yellowish brown (male) with darker pigmentation anteriorly. Metasomal yellowish brown, darker in male; telson yellowish brown; base of aculeus yellowish and tip reddish. Chelicerae yellowish with conspicuous variegated brownish spot; fingers brownish with reddish teeth. Pedipalps yellowish brown (female) to reddish brown (male); fingers darker than chela manus, reddish brown (female) to almost blackish (male). Legs yellowish brown, intensely spotted with brownish. Venter, coxapophysis and sternum brownish yellow; sternites yellowish with the VII darker; genital operculum and pectines pale yellow.

Morphology.

Carapace moderately granular; furrows moderately deep. Median eyes anterior to the middle of carapace; three pairs of lateral eyes, the third pair only slightly smaller than the first two. Sternum pentagonal, slightly longer than wide. Tergites moderately granular; VII with five carinae, moderately marked; median carinae vestigial. Pectines large in male and reduced in female with a pectinal tooth count of 8–8 and 7–7, respectively; two marginal and one middle lamellae present; fulcra present in adult specimens, absent immatures. Sternites smooth, with oval spiracles; sternite VII with four vestigial carinae and some minute granulations. Metasomal segments I to V with 10-8 - 8 - 8 - 7 carinae; dorsal carinae on segments II to IV with several spinoid granules and one larger posterior spinoid granule; metasomal tegument moderately granulated; ventral carina on segment V without spinoid granules. Telson vesicle almost smooth, only some minute granulation laterally; annular ring conspicuous in both sexes; telson length / depth ratio 2.92 in male, 3.82 in female. Setation weak on metasomal segments and telson. Pedipalps: femur with dorsal internal, dorsal external, ventral internal and ventral external carinae strongly marked; tegument moderately granular. Patella with dorsal internal, dorsal external, ventral internal, ventral external and external carinae strongly marked; two strongly marked spinoid granules present on internal aspect, ventral bigger than dorsal; tegument moderately granular. Chela with dorsal marginal, external secondary, ventral internal and ventral carinae strongly marked; other carinae moderate; tegument moderately granulated. Sexual dimorphism strongly marked with male pedipalps markedly elongated; chela length / width ratio 5.35 in male, 3.95 in female. Chelal fingers undulate in both sexes; movable fingers with two parallel longitudinal rows of granules almost fused, formed by a row of about 97 median granules and a row of about 72 inner accessory granules; 3–4 inner granules and 13–15 outer granules are also present. Cheliceral dentition as defined for the family ( Vachon 1963); 4–5 teeth on ventro-internal face of movable finger. Trichobothriotaxy of type C ( Vachon 1974, 1980); three trichobothria on femur (dorsal, internal and external); patella with 2 dorsal, 1 internal, 11–12 ventral and 18 external trichobothria; chelal manus with 4 ventral, 2 dorsal (Dt, Db), 2 internal (ib, it), 1 Est, 5 Et, 1 Esb and 3 trichobothria in the Eb series. Trichobothrium Eb 3 distal in relation to Eb 2 ( Vachon 1974, 1980), located in distal half of manus, between trichobothria Dt and Est. Legs tarsi with 4–5 long setae on lateral and dorsal surfaces and 5–8 ventral spines; tibial spurs absent.

Morphometric values.

Adult male holotype and adult female paratype of Scorpiops (Euscorpiops) doiphukha sp. nov. Total length including the telson 70.33 / 63.29. Carapace: length 13.13 / 11.13; anterior width 6.13 / 5.25; posterior width 10.75 / 10.00. Mesosoma length 25.38 / 24.63. Metasomal segments. I: length 3.13 / 2.63, width 3.63 / 3.00; II: length 3.38 / 2.88, width 3.38 / 2.88; III: length 3.63 / 3.38, width 3.13 / 2.88; IV: length 4.38 / 3.88, width 3.00 / 2.75; V: length, 8.25 / 7.13, width 3.00 / 2.75, depth 3.00 / 2.50. Telson length 8.75 / 7.63; vesicle: width 2.75 / 2.00, depth 3.00 / 2.00. Pedipalp: femur length 15.13 / 10.63, width 3.63 / 3.63; patella length 12.75 / 8.88, width 3.63 / 3.75; chela length 26.75 / 20.75, width 5.00 / 5.25, depth 4.38 / 5.13. Movable finger length 11.50 / 10.25.

Relationships.

In respect to several characters, the most similar species seem to be S. (E.) dii , S. (E.) orioni , and S. (E.) prasiti , described from the Thailand Provinces of Phrae, Chiang Mai, and Mae Hong Son, respectively (Fig. 4 ). Scorpiops doiphukha sp. nov. can however be separated from these species notably by the following main features:

larger size with 70.3 mm in male (38 mm in S. dii , 49 mm in S. orioni , 52 mm in S. prasiti ) and 63.3 mm in female (58 mm in S. dii , 58 mm in S. orioni , 53 mm in S. prasiti ) with male larger than female (female larger than or equivalent to male in all three species);

male telson deeper with length to depth ratio 2.92 (3.26 in S. dii , 3.4 in S. orioni and S. prasiti );

pedipalp chela slenderer than in S. dii and S. orioni with length to width ratio 5.35 in male (3.10 in S. dii , 4.60 in S. orioni ) and 3.95 in female (3.17 in S. dii , 3.0–3.4 in S. orioni );

pedipalp chela movable fingers with about 72 inner accessory granules (50–56 in S. dii ) and 3–4 inner granules (6 in S. dii and S. orioni , 7 in S. prasiti );

pedipalp patella with 11–12 ventral and 18 external trichobotria (14–15 and 20–22 respectively in S. prasiti ).

The new species can also be distinguished from the other geographically closest species (Fig. 4 ), notably by the following main features:

S. (E.) tangae , described from Vientiane Province, Laos: smaller, with 33 mm in male; male pedipalp chela wider with length to width ratio 3.7; pedipalp chela movable fingers with about 73 median granules and 45 inner accessory granules.

S. (E.) chiangmai , described from Chiang Mai Province, Thailand: pedipalp patella with 17 ventral and 16 external trichobotria.

S. (E.) problematicus , described from Chiang Mai Province, Thailand: smaller, with 46 mm in male and 47 mm in female; male telson thinner with length to depth ratio 3.3; pedipalp chela wider with length to width ratio 3–3.33 in both sexes; pedipalp chela movable fingers with about 75 median granules and 5–6 inner granules.

S. (E.) alexandreanneorum , described from Luang Prabang Province, Laos: smaller, with 38 mm in both sexes; male telson thinner with length to depth ratio 3.9; male pedipalp chela slenderer with length to width ratio 6.8; male pedipalp fingers straight; pedipalp chela movable fingers with about 70 median granules and 8 outer granules; pedipalp patella with 14 ventral and 21 external trichobotria.

S. (E.) kubani , described from Phongsaly Province, Laos: smaller, with 39 mm in male and 44 mm in female; male telson thinner with length to depth ratio 3.5; pedipalp chela wider with length to width ratio 3.1–3.2 in both sexes; pedipalp chela movable fingers with about 70 median granules and 50 inner accessory granules.

S. (E.) vachoni , described from Yunnan Province, China: smaller, with 47–54 mm in male and 42–55 mm in female; pedipalp chela wider with length to width ratio 2.8–3.2 in both sexes; pedipalp chela movable fingers with 6–8 inner granules.

S. (S.) oligotrichus , from Luang Prabang and Xiangkhouang Provinces: smaller, with 32–50 mm in both sexes; male telson thinner with length to depth ratio 3.3–3.5; male pedipalp chela wider with length to width ratio 3.2; female pedipalp fingers straight; pedipalp chela movable fingers with about 55 median granules, about 40 inner accessory granules and 9 outer granules; pedipalp patella with 9 ventral trichobotria; trichobothrium Eb 3 located in proximal half of manus, between trichobothria Dt and Db.

S. (S.) farkaci , described from Mae Hong Son Province, Thailand: smaller, with 25–33 mm in male and 27–37 mm in female; female telson deeper with length to depth ratio 2.8; pedipalp chela wider with length to width ratio 2.7–3.1 in male and 2.4–25 in female; female pedipalp fingers straight; pedipalp chela movable fingers with about 55 median granules and 25–30 inner accessory granules; pedipalp patella with 9 ventral trichobotria; trichobothrium Eb 3 located in proximal half of manus, between trichobothria Dt and Db.

Figures

Figure 1. Scorpiops (Euscorpiops) doiphukha sp. nov. A, B. Male holotype, habitus, dorsal and ventral aspects, respectively; C, D. Female paratype, habitus, dorsal and ventral aspects, respectively. Scale bar: 2 cm.

Figure 2. Scorpiops (Euscorpiops) doiphukha sp. nov. Male holotype, trichobotrial pattern. A. Metasomal segment V and telson, lateral aspect; B. Femur, dorsal aspect; C – E. Chela; C. Dorsal, ventral, and external aspects, respectively; F – H. Patella, dorsal, external, and ventral aspects, respectively. Scale bars: 5 mm.

Figure 3. Scorpiops (Euscorpiops) doiphukha sp. nov., alive. A. Male holotype and female paratype, in their natural habitat; B. Female, alive with pre-juveniles (instar I).

Figure 4. Map showing the type locality of Scorpiops (Euscorpiops) doiphukha sp. nov. and the distribution of the geographically closest Scorpiops species discussed in this work.