Heterometrus gravimanus ( Pocock, 1894 )

Kovařík, František, Lowe, Graeme, Ranawana, Kithsiri B., Hoferek, David & Š, V. A., 2016, Scorpions of Sri Lanka (Scorpiones Buthidae, Chaerilidae, Scorpionidae) with description of four new species of the genera Charmus Karsch, 1879 and Reddyanus Vachon, 1972, stat n, Euscorpius 220, pp. 1-133 : 96-103

Heterometrus gravimanus ( Pocock, 1894)

( Figs. 15 , 458–481 , 572 )

Scorpio gravimanus Pocock, 1894: 75–76 .

Heterometrus (Srilankametrus) gravimanus: Tikader & Bastawade, 1983: 550–555 , figs. 1469–1482; Fet, 2000: 446;

Heterometrus gravimanus: Kovařík, 2004: 15 , 17, fig. 15; Kovařík, 2009: 38, 79, figs. 40–42.

TYPE LOCALITY AND TYPE REPOSITORY. Ceylon, now Sri Lanka; BMNH.

SRI LANKAN MATERIAL EXAMINED. Sri Lanka, Southern Province, Galle , 1♂, FKCP, IV.1994, leg. P. Senft ; North Central Province, Polonnaruwa District, Giritale, 08°01'26.0"N 080°54'37.2"E, 233 m a.s.l. ( Locality 15CE, Fig. 579 ), 22. –23. IV.2015, 2♂ ( Figs. 458–459 , 462, 464 , 470–472, 475–479 , 480 , 572 ) 1♀ ( Figs. 460– 461 , 463, 465 , 473 ), FKCP, 1♀ 7juvs., UPSL, leg. Kovařík et al.; Northern Province, Jaffna District, 09° 42'51.6"N 080°04'44.8"E, 19 m a.s.l. ( Locality 15CJ, Figs. 586–587 ), 26. –27. IV.2015, 2♂ ( Figs. 466–468 , 474 ), 1♀ ( Fig. 469 ), FKCP, leg. Kovařík et al.

DIAGNOSIS. Total length 75–110 mm long. Color of adults uniformly reddish brown. Pectinal teeth number 13–16 in males and 11–13 in females. Male with slightly longer pedipalp femur and patella. Chela lobiform, narrower in male than female; chela length/ width ratio 1.79–2.05 in males, 1.65–1.75 in females. Entire manus covered by rounded granules, with five carinae mainly in anterolateral part. Pedipalp patella smooth, without pronounced internal tubercle. Carapace smooth, glossy. Spination formula of tarsomeres II of legs: 4/4-5: 4/5: 4/5-6: 4/5-6. Telson elongate, vesicle shorter than aculeus.

HEMISPERMATOPHORE ( Figs. 476–479 ). Lamelliform. Distal lamina long, slender, basal capsular portion one fifth of total lamina length, wider, dorsal trough nearly flat with slightly elevated transverse strip, bordered internally by strong carina; portion of lamina just distal to hook constricted, curved, deflected internally; distal terminus of lamina dilated, truncated and spatulate. Hook prominent, with narrowed 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.

The hemispermatophore is quite similar to those of several other species of Heterometrus previously illustrated as line drawings: H. longimanus ( Herbst, 1800) , H. cyaneus (C.L. Koch, 1836) and H. spinifer (Ehrenberg, 1828) ( Couzijn, 1981; Stockwell, 1989). The relative proportions of the distal lamina and trunk are comparable and the same capsular structures or lobes are present. Some differences can be seen: (i) in H. cyaneus and H. spinifer , the distal lamina is straight, not internally deflected; (ii) the hook is smaller in H. longimanus and H. cyaneus , and has a shorter tip in H. spinifer ; (iii) the distal lamina is not terminally dilated in H. longimanus and H. cyaneus . However, the extent of intraspecific morphological variation in Heterometrus hemispermatophores is unknown, so it is unclear if these differences have diagnostic value.

VARIABILITY. The figures 470–475 show variability in the shape of the chela in adult males. The greatest difference is between the 77 mm long male ( Fig. 475 ) and the 105 mm long male ( Fig. 470 ) from the same locality 15CE.

DISTRIBUTION. India and Sri Lanka.

Figures

Figures 12–15: Maps showing the known geographical distribution of the Sri Lankan species.

Figures 458–461: Heterometrus gravimanus from locality 15CE. Figures 458–459. Male in dorsal (458) and ventral (459) views. Figures 460–461. Female, dorsal (460) and ventral (461) views. Scale bar: 10 mm.

Figures 462–469: Heterometrus gravimanus. Figures 462, 464. Male from locality 15CE, chelicerae, carapace and tergites I– II (462), and sternopectinal region with sternites III–IV (464). Figures 463, 465. Female from locality 15CJ, chelicerae, carapace and tergites I–II (463), and sternopectinal region with sternites III–IV (465). 466–468. Male from locality 15CJ, tarsomeres of third (466) and fourth (467) legs retroventral views, and telson with metasomal segment V in lateral view (468). Figure 469. Female from locality 15CJ, telson with metasomal segment V in lateral view.

Figures 470–475: Heterometrus gravimanus. Figures 470–472. Male 105 mm long from locality 15CE, pedipalp chela in dorsal (470), external (471) and ventral (472) views. Figure 473. Female from locality 15CE, pedipalp chela in dorsal view. Figures 474. Male 106 mm long from locality 15CJ, pedipalp chela in dorsal view. Figures 475. Male 77 mm long from locality 15CE, pedipalp chela in dorsal view.

Figures 476–479: Right hemispermatophore of Heterometrus gravimanus from locality 15CE. External (476), dorsal (477), internal (478) and ventral (479) views. Scale bar: 2 mm. Abbreviations: bl, basal lobe; dl, distal lamina; dtdl, dorsal trough of distal lamina; h, hook; ml, median lobe; mtt, median transverse trough; pl, proximal lobe; t, trunk.

Figures 480–481: Heterometrus gravimanus, male (480) and female (481) at locality 15CE.

Figures 571–574: Key characters for distinguishing Sri Lankan Heterometrus. Figures 571–572. Pedipalp chela dorsal view of male, Heterometrus serratus from locality 15CP (571) and Heterometrus gravimanus from locality 15CE (572). Figures 573– 574. Metasomal segments IV-II lateral view of female, Heterometrus indus from locality 15CA (573) and Heterometrus serratus from locality 15CP (574).

Figures 579–581: Figures 579–580. Locality 15CE, Sri Lanka, North Central Province, Polonnaruwa District, Giritale, 08°01'26.0"N 080°54'37.2"E, 233 m a.s.l. During night collecting on 22.–23.IV.2015 in the hotel garden (UV detection) we recorded Heterometrus swammerdami (inside the termite constructions, Fig. 580) and Heterometrus gravimanus inside burrows in open terrain. The mothers had 30 to 60 cm long oblique burrows usually once curved from which several narrow burrows created by their juveniles separated under surface. Every burrow of juveniles has a proper exit 15 to 90 cm from the main exit of the motherś burrow. On the locality we recorded night temperature 32.8 ºC– 26.5 ºC (minimum temperature) and night humidity varied between 51% and 79%. Figure 581. Locality 15CF, Sri Lanka, North Central Province, Polonnaruwa District, near Kaudulla National Park, 08°08'40.6"N 080°51'04"E, 101 m a.s.l. During a day 23.IV.2015 we recorded Buthoscorpio sarasinorum (under stones or woods), Isometrus thwaitesi (under dry bark of standing trees), Reddyanus besucheti (under stones), and Chaerilus ceylonensis (under stones).

Figures 585–587: Figure 585. Locality 15CI, Sri Lanka, Northern Province, Mannar District, Marichchukkaddi env, border of Wilpattu National Park, 08°33'32.3"N 079°56'51"E, 7 m a.s.l. During night collecting on 25.–26.IV.2015 (UV detection) we recorded Isometrus maculatus and Isometrus thwaitesii sympatrically (running on branches and trunks of trees, also sitting on leaves one to four metres high), Reddyanus ceylonensis sp. n. (on the land among leaves; the type locality), Reddyanus loebli (hidden under scales of bark of standing tree trunks). Near to the locality we recorded temperature between 37.6 ºC (maximum daytime temperature and 26.2 ºC (minimum nighttime temperature) shortly before sunrise. Humidity varied between 67% and 81%. Figures 586–587. Locality 15CJ, Sri Lanka, Northern Province, Jaffna District, 09°42'51.6"N 080°04'44.8"E, 19 m a.s.l. During night collecting on 26.–27.IV.2015 (UV detection) we recorded Lychas srilankensis (on the land usually under branches, leaves or in their vicinity), Heterometrus swammerdami (inside the termite constructions or inside heaps of garden "waste") and Heterometrus gravimanus inside burrows in open terrain (Fig. 587). The females had 30 to 60 cm long oblique burrows once or twice curved. A female shortly after maturity ecdysis was in the burrow together with a male; another female was in the burrow together with three juveniles which had their own narrow burrows separated under surface from the motherś burrow; a juvenile after the third ecdysis had a proper burrow 30 cm long oblique and once curved. There also lives Isometrus maculatus. On the locality we recorded night temperature 31.6 ºC– 27.2 ºC (minimum temperature) and night humidity varied between 60% and 87%.