Heterometrus serratus (Pocock, 1900)

(Figs. 15, 508–534, 571, 574)

Palamnaeus serratus Pocock, 1900: 86, 97.

Heterometrus serratus: Takashima, 1945: 94.

Heterometrus (Srilankametrus) serratus: Tikader & Bastawade, 1983: 555–561, figs. 1483–1496; Fet, 2000: 448.

Heterometrus indus indus (in part): Couzijn, 1981: 121– 123, fig. 35 (in part).

Heterometrus indus (in part): Kovařík, 2004: 17–20, fig. 16; Kovařík, 2009: 38.

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

TYPE MATERIAL EXAMINED. Sri Lanka, Ceylon, 1♂ (holotype, fig. 16 in Kovařík, 2004: 19), leg. Dr. Ondaatje, BMNH No. 1888.55.

OTHER MATERIAL EXAMINED. Sri Lanka, Southern Province, Matara District, Kekanadura village, 05° 58'28.2"N 080°36'20.5"E, 40 m a.s.l. (Locality 15CP, Fig. 594), 30.IV.2015, 1♂ (Figs. 509–513, 516, 518, 520–522, 571) 1♀ (Figs. 508, 514–515, 517, 519, 523– 529, 574), FKCP, 1♀ im., UPSL, leg. Kovařík et al.; Uva Province, Monaragala District, Monaragala, 06°52' 30.7"N 081°21'17"E, 288 m a.s.l. (Locality 15CQ, Fig. 595), 2.–3.V.2015, 2♀, FKCP, leg. Kovařík et al.

DIAGNOSIS. Total length 100–130 mm long. Color of adults uniformly reddish black to greenish black. Pectinal teeth number 12–15 in both sexes. Male with slightly narrower chela than female; chela length/ width ratio 1.79–1.94 in males, 1.69 in female. Chela hirsute, lobiform, without carinae on dorsoexternal surface, but may bear rows of granules. Chela length/ width ratio 1.8–2.0 in adults. Entire manus covered by rounded granules that may merge and appear as rows. Pedipalp patella without pronounced internal tubercle. Carapace smooth, glossy medially, with granules at margins. Second metasomal segment approximately as long as wide. Fifth segment of metasoma about as long pedipalp femur, fourth segment of metasoma shorter than pedipalp femur. Dorsal and dorsolateral carinae of metasomal segments granulated. Vesicle of telson usually longer than aculeus. Spination formula of tarsomeres II of legs: 3-4/4-6: 4/4-5: 4/5-6: 4/5-7.

COMMENTS. Palamnaeus serratus Pocock, 1900 was synonymized with H. indus by Couzijn (1981: 121). The first author (Kovařík, 2004: 17 and Kovařík, 2009: 38) accepted the synonymy, whereas Tikader & Bastawade (1983: 555) considered H. serratus a valid species. Examination of additional specimens collected during the Sri Lankan expedition of 2015 convinced us that H. serratus is in fact a valid species. Pocock (1900: 86) differentiated H. serratus and H. indus as follows: 1) dorsal and dorsolateral carinae of metasomal segments granulated in H. serratus (Fig. 574), smooth in H. indus (Fig. 573). We found other minor differences: 2) sexual dimorphism in proportions of pedipalps not noticeable in H. indus, male with slightly narrower chela than female in H. serratus (chela length to width ratio 1.79–1.94 in males, 1.69 in the females); 3) carapace smooth and glossy, only occasionally with granules at margins in H. indus (Figs. 486–487); carapace smooth and glossy medially, always with more granules at margins in H. serratus (Figs. 516–517); 4) spination formula of tarsomeres II of legs: 3/4: 2-4/3-4: 4/4-5: 4/ 5 in H. indus; 3-4/4-6: 4/4-5: 4/5-6: 4/ 5-7 in H. serratus.

The distribution of H. serratus was previously unknown, as the type locality was imprecise and the holotype male was the only known specimen. We collected additional specimens at localities cited here as 15CP (Fig. 594) and 15CQ (Fig. 595). Our data suggest that H. serratus is distributed in the southern part, and H. indus in the central part of Sri Lanka (Fig. 15).

DISTRIBUTION. Sri Lanka.