Heterometrus yaleensis, Kovařík & Ranawana & Sanjeewa Jayarathne & Hoferek & Šťáhlavský, 2019

Kovařík, František, Ranawana, Kithsiri B., Sanjeewa Jayarathne, V. A., Hoferek, David & Šťáhlavský, František, 2019, Scorpions of Sri Lanka (Arachnida Scorpiones) Part III Heterometrus yaleensis sp n (Scorpionidae), Euscorpius 283, pp. 1-13 : 2-9

Heterometrus yaleensis sp. n.

( Figures 1–53, Table 1) http://zoobank.org/urn:lsid:zoobank.org:act:DC95D39E-

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TYPE LOCALITY AND TYPE REPOSITORY. Sri Lanka, Southern Province, Yale National Park , 06°13'48.1"N 81°20'27.7" E, 7 m. a.s.l. (Locality 18 CE) , FKCP (the first author collection).

TYPE MATERIAL. Sri Lanka, Southern Province, Yale National Park , 06°13'48.1"N 81°20'27.7"E, 7 m. a. s. l. (Locality 18 CE) , 8.-9.III.2018, 1♂ (holotype) 1♀ (paratype), leg. Kovařík et al.; 06°23'46.5"N 81°23'34.1"E, 40 m. a. s. l. (Locality 18 CC) , 7.-8.III.2018, 1♀ (paratype), leg. Kovařík et al.

ETYMOLOGY. Named after Yale National Park, which includes both localities of the new species.

DIAGNOSIS. Total length of adults 75 (male) to 103 (female) mm. Base color uniformly reddish brown to black, telson yellow to reddish brown, legs yellow to reddish brown, lighter than body. Chelicerae yellow with dark reticulation, anterior manus and fingers reddish black. Pectines with 13–14 teeth in both sexes. Male pedipalp chela, femur and patella narrower and longer than female, ratio chela length/ manus width 2.04 in male, 1.88 in female. Chela lobiform in both sexes, strongly tuberculate with pronounced carination, including dorsointernal carina on chela in both sexes. Patella of pedipalp with several small internal tubercles. Carapace smooth, very sparsely granulated laterally. Metasomal segment I wider than long, length/ width ratio 0.80–0.86 in both sexes. Telson hirsute, elongate, ventrally sparsely granulate, vesicle approximately as long as aculeus.

Description. Total length male holotype 75.3 mm, female paratype 102.8 mm. Coloration ( Figs. 1–4, 51–52): base color uniformly reddish brown to black; telson and sternopectinal area yellow to reddish brown; legs yellow to reddish brown, lighter than body. Measurements of the carapace, telson, segments of the metasoma and segments of the pedipalps are given in Table 1.

Chelicerae ( Figs. 26–27). Chelicerae yellow strongly reticulate, anterior part reddish black. Fingers reddish brown to black. Dentition typical for the genus, teeth sharp. Tegument basally smooth and glossy without granulation.

Pedipalps ( Figs. 5–21). Orthobothriotaxic type C. Pedipalp femur with three trichobothria, only one of which lies on the internal surface. Patella of pedipalp with 19 trichobothria ( Figs. 16–18), one internal, two dorsal, three ventral and 13 external. Chela of pedipalp with standard 26 trichobothria ( Figs. 13–15). Male with fingers, chela, femur and patella of pedipalp narrower and longer than female, ratio of chela length/ manus width 2.04 in male, 1.88 in female. Chela lobiform in male, strongly tuberculate with pronounced carination, including dorsointernal carina in both sexes. Patella smooth with seven obsolete carinae developed, with several small internal tubercles. Femur smooth, with four granulate carinae developed. Fingers extremely short, especially the fixed finger of the female ( Fig. 21).

Carapace ( Figs. 36 and 38). Slightly trapezoidal (narrower anteriorly) and slightly longer than wide; anterior margin strongly concave medially. Tegument smooth very sparsely granulated laterally. Median and posteriolateral furrows wide and deep, others absent. Median eyes large and raised; three pairs of lateral eyes of the same size, aligned along each anterolateral corner.

Mesosoma ( Figs. 1–4, 36–39). Tergites smooth, lacking carinae. Sternum standard for the genus: type 2 with six sides, with posterior emargination and convex lateral lobes, vertical compression absent, apex width slightly narrower than posterior width. Pectines of typical size for the genus, short, wide and setose. Pectinal tooth count 13–14 in both sexes. Pectines with 3 marginal lamellae, 4 middle lamellae. Sternites lack carinae, surfaces smooth and sparsely setose. Posterior margins of sternites IV-VI each with smooth median patch.

Legs ( Figs. 22–25). Retrolateral pedal spurs absent. Lateroapical margins of tarsi produced into rounded lobes. Legs smooth, without carinae and granules, unevenly hirsute. Tarsomere I hirsute. Tarsomere II with spiniform setae and several spines. Spiniform seta formula of tarsomere II is 4/4: 4/4: 5/4: 5/4.

Metasoma and telson ( Figs. 28–35).All segments with carinae developed. All carinae on metasoma V and dorsal carinae on metasoma II-IV granulate, others smooth. Metasomal segment I wider than long, length/ width ratio 0.80–0.86 in both sexes. The metasoma I-IV with eight carinae, metasoma V with seven carinae. All metasomal segments completely smooth without granules. Several minute granules present only on dorsal aspect of metasoma V. Metasoma sparsely hirsute with long reddish macrosetae. Telson hirsute with long macrosetae, smooth, sparsely granulated ventrally. Vesicle elongate, lateral profile elliptic or weakly pyriform. Aculeus curved with thick base, distally sharply bent, approximately as long as vesicle.

Hemispermatophore ( Figs. 43–45). Lamelliform. Distal lamina long, slender, basal capsular portion short, ca. 10% of total lamina length, wider, dorsal trough nearly flat with slightly elevated transverse strip, bordered internally by strong carina; portion of lamina distal to hook uniform in width throughout most of its length; distal terminus of lamina rounded, slightly tapered, not dilated or expanded. Hook prominent, with curved, sharp tip and wide triangular base, lacking dorsal trough. Median lobe elongate, extending from base of hook to truncal flexure, with fine longitudinal carina and trough along internal side. Inner lobe and median transverse trough large, prominent. Basal and proximal lobes smaller but well developed, blunt, rounded. All lobes of capsule region smooth, without barbs or spicules. Trunk broader than both capsule and distal lamina, parallel-sided, with moderately sclerotized diagonal axial rib.

Karyotype ( Figs. 46–48). We analyzed the male holotype. The diploid number of this species is 99 chromosomes ( Fig. 46). During pachytene and metaphase I we identified also one quadrivalent and one trivalent in additon to 46 bivalents ( Figs. 47, 48). The chromosomes that form multivalents have different lengths. The quadrivalents comprise the two longest chromosomes of the karyotype (1.86 % and 1.71 % of the diploid set) and two shorter chromosomes (1.07 % and 0.89 % of the diploid set). The tetravalent comprises one longer chromosome (1.38 % of the diploid set) and two very short chromosomes (0.71 % and 0.61% of the diploid set). Despite the different lengths, all chromosomes that form multivalents seem to be metacentric. Metacentric morphology of chromosomes predominate also in bivalents (34 pairs). We identified only seven pairs of submetacentric (pairs Nos. 9, 11, 18, 20, 29, 42, 43), three pairs of subtelocentric (pairs Nos. 35, 38, 41) and two pairs of telocentric chromosomes (pairs Nos. 45, 46).

AFFINITIES. The described features distinguish H. yaleensis sp. n. from all other species of the genus. H. yaleensis sp. n. is reliably distinguished from all other Heterometrus species by the unique carination of the chela, with a strongly developed dorsointernal carina ( Figs. 5 and 13 versus figs. 180–231 in Kovařík, 2009: 99–101). Other major taxonomically important characters are the shape and granulation of the pedipalp chela with extremely short fixed finger ( Figs. 5 and 13) and the spiniform seta formula of tarsomere II 4/4: 4/4: 5/4: 5/4.

COMMENTS ON LOCALITIES AND LIFE STRATEGY. At the type locality (Locality No. 18CE, Southern Province, Yale National Park, 06°13'48.1"N 81°20'27.7"E, 7 m. a.s.l.) and locality No. 18CC (Southern Province, Yale National Park, 06°23'46.5"N 81°23'34.1"E, 40 m. a.s.l.) H. yaleensis sp. n. constructed oblique 30 to 50 cm long burrows once or twice curved, situated in open terrain ( Figs. 49–50). On the ground among leaf litter we also recorded at both of these localities Lychas srilankensis Lourenço, 1997 and at locality 18CC Reddyanus basilicus ( Karsch, 1879) .

At locality 18CC we recorded temperature varied from 31 ºC (maximum temperature at day) to 24.7 ºC (minimum temperature at night) and humidity varied between 48% and 78%. At the locality 18CE we recorded a minimum nighttime temperature of 24.3 ºC (temperature) and nighttime humidity of 65%.