Terrathelphusa kundong, Grinang, Jongkar & Ng, Peter K. L., 2015

Grinang, Jongkar & Ng, Peter K. L., 2015, The identity of the semiterrestrial crab Terrathelphusa kuchingensis (Nobili, 1901) (Crustacea: Decapoda: Brachyura: Gecarcinucidae), with descriptions of four new species from southwestern Sarawak, Borneo, Malaysia, Zootaxa 3946 (3), pp. 331-346 : 338-340

Terrathelphusa kundong n. sp.

( Figs. 7 A–H, 8A–E, 11G, H)

Terrathelphusa kuchingensis— Ng & Grinang 2004: 314 (part), fig. 7 (not Potamon (Geothelphusa) kuchingensis Nobili, 1901 ).

Material examined. Holotype: male (29.4 × 21.9 mm) ( ZRC 2015.0004), middle elevation of Gunung Serambu, Bau, Sarawak, 1O25’50.4”N 110O13’04.3”E, 340 m asl, coll. J. Grinang et al., 24 April 2013. Paratype: 2 females (larger 30.8 × 23.0 mm) (SBC.C.00364–65), data same as holotype; 1 female (34.9 × 25.3 mm) (SBC.C.00366), flat bank of Sungai Bukan Kagap, base of Gunung Serambu at Podam area, Bau, Sarawak, 1O25’38.4”N 110O12’29.4”E, 34 m asl, coll. J. Grinang et al., 13 March 2013; 3 males (largest 36.2 × 25.3 mm), 2 females (larger 30.0 × 22.0 mm) (SBC.C.00367–71), foothill of Gunung Sewa, Giam area, Padawan-Penrissen limestone formation, Sarawak, 1O19’01.2”N 110O16’22.2”E, 49 m asl, coll. J. Grinang et al., 21 September 2013; 1 female (36.3 × 24.8 mm) (SBC.C.0072), secondary forest, sandstone, Bung Bratak, Bau, Sarawak, 1O28’17.4”N 110O05’13.5”E, 100 m asl, coll. S.T. Pang et al., 1 December 2013; 1 female (24.6 × 17.7 mm) (SBC.C.00373), foothill of Gunung Sewa, Giam area, Padawan-Penrissen limestone formation, Sarawak, coll. Anang et al., 22 August 2008; 2 males, 1 female ( ZRC 2014.0843), forest next to rubber and cocoa plantations, base of Gunung Sewa, Giam area, Padawan-Penrissen limestone formation, Sarawak, coll. J. Grinang et al., 14 September 2013; 1 female (SBC.C.00014), Bau limestone formation, Gunung Tai Ton, Bau, Sarawak, coll. J. Grinang et al., 13 November 2001; 1 female (SBC.C.00015), Bau limestone formation, Gunung Tai Ton, Bau, Sarawak, coll. A. Denis et al., 13 November 2001; 1 female (SBC.C.00049), Bau limestone formation, Gunung Tai Ton, Bau, Sarawak, coll. J.

Grinang et al., 14 April 2002; 1 female (21.6 × 16.2 mm) ( ZRC), Bau limestone formation, Gunung Aup, Bau, Sarawak, coll. J. Grinang et al., 14 May 2002 (det. as Terrathelphusa kuchingensis by Ng & Grinang, 2004); 2 females (larger 30.8 × 22.1 mm) (SM Cru.1986.144–145), Bidi, Bau, Sarawak, coll. C. J. Brooke, June 1903 (det. as Terrathelphusa kuchingensis ).

Diagnosis. Carapace broader than long, conspicuously swollen, surface convex, smooth; cervical grooves broad, deep; epigastric cristae high, separated by deep epigastric groove; H-groove deep, long almost confluent with cervical grooves; epibranchial tooth indistinct but can be separated from external orbital angle by notch, anterolateral, frontal regions appearing compressed, supraorbital margin almost parallel with frontal margin; epistome median lobe blunt to bifurcated ( Fig. 7 A–C). Male abdomen with elongated somite 6, lateral margins gently concave ( Fig. 7 D). Third maxilliped ischium rectangular, about 1.9 times maximum width ( Fig. 7 E). Ambulatory legs smooth, relatively slender, second pair longest; length of fourth merus about 3.8 times width ( Fig. 7 F). Cheliped carpus rugose, without granules ( Fig. 7 G, H), inner angle with broadly triangular tooth; gap between fingers of major chela wide ( Fig. 7 A). G1 gently curving outwards; terminal segment cone-shaped, tapered, gently curving upwards, about 0.3 times length of subterminal segment ( Fig. 8 A, B, D, E). Distal segment of G2 relatively long, about 0.6 times length of basal segment ( Fig. 8 C).

Life colour. Carapace is grape-purple with whitish cream legs and chelipeds ( Fig. 11 G–H).

Variation. The paratypes agree well with the holotype male except in some non-sexual characters: the tip of the median lobe of the epistome varies from blunt to bifurcated that was not determined by size or sex. The cervical grooves are proportionately broader and the ambulatory legs relatively longer in larger specimens.

Habitat. Widely distributed in limestone and sandstone outcrops, from lowlands to mid- elevations of mountains. The burrows are shallower in sandstone possibly because of the compact soil, whereas burrows are deeper (approximately more than 1 m) in the loose soil at the base of limestone hills.

Etymology. The name is derived from the Iban word kundong alluding to the dark crimson carapace that is very similar to the ripe fruit of a plant of the same name ( Garcinia parvifolia ). The name is used as a noun in apposition.

Remarks. Terrathelphusa kundong n. sp., can be distinguished from T. kuchingensis and the other new species being described herein by a combination of characters: inner angle of carpus with broadly triangular tooth ( Fig. 7 A) (acutely triangular tooth in other species; Figs. 1 A, 3A, 5A, 9A) and the G1 terminal segment distinctly curving upwards ( Fig. 8 A, B, C, D) (gently curving upwards in other species; Figs. 2 A, B, D, E; 4A, B, D, E; 6A, B, D, E; 8A, B, D, E; 10A, B, D, E). Examination of the specimens previously identified as T. kuchingensis in the Sarawak Museum and Sarawak Biodiversity Centre from areas adjacent to the type locality show that they should be transferred to T. kundong n. sp., instead.

Figures

FIGURE 1. Terrathelphusa kuchingensis (Nobili, 1901), male (36.0 × 26.4 mm) (ZRC 2015.0001), Gunung Temurang, Kuching, Sarawak, Padawan-Penrissen limestone formation. A, overall dorsal view; B, dorsal view of carapace; C, frontal view of carapace; D, ventral view showing anterior thoracic sternum and male abdomen; E, left third maxilliped; F, outer view of right fourth ambulatory leg; G, outer view of right chela; H, outer view of left chela.

FIGURE 2. Terrathelphusa kuchingensis (Nobili, 1901), male (36.0 × 26.4 mm) (ZRC 2015.0001), Gunung Temurang, Kuching, Sarawak, Padawan-Penrissen limestone formation. A, ventral view of left G 1; B, ventral view of distal part of left G 1; C, dorsal view of left G 2; D, dorsal view of G 1; E, dorsal view of distal part of left G 1. Scales: A, C, D = 1 mm; B, E = 0.5 mm.

FIGURE 7. Terrathelphusa kundong n. sp., holotype male (29.4 × 21.9 mm) (ZRC 2015.0004), sandstone outcrop, Gunung Serambu, Bau, Kuching, Sarawak. A, overall dorsal view; B, dorsal view of carapace; C, frontal view of carapace; D, ventral view showing anterior thoracic sternum and male abdomen; E, left third maxilliped; F, outer view of right fourth ambulatory leg; G, outer view of right chela; H, outer view of left chela.

FIGURE 8. Terrathelphusa kundong n. sp., holotype male (29.4 × 21.9 mm) (ZRC 2015.0004), sandstone outcrop, Gunung Serambu, Bau, Kuching, Sarawak. A, ventral view of left G 1; B, ventral view of distal part of left G 1; C, dorsal view of left G 2; D, dorsal view of G 1; E, dorsal view of distal part of left G 1. Scales: A, C, D = 1 mm; B, E = 0.5 mm.

FIGURE 11. Life colour of five species of Terrathelphusa from Kuching Division, Sarawak. A, B, Terrathelphusa kuchingensis (Nobili, 1901), male (36.0 × 26.4 mm) (ZRC 2015.0001), shortly after collection, Gunung Temurang; C, D, Terrathelphusa aglaia n. sp., holotype male (35.9 × 26.6 mm) (ZRC 2015.0002), Gunung Penrissen; E, F, Terrathelphusa cerina n. sp., female (24.2 × 20.1 mm), captured-marked-released, Gunung Singai; G, H, Terrathelphusa kundong n. sp., female (30.8 × 23.0 mm) (SBC. C. 00364 - 65), Gunung Serambu; I, J, Terrathelphusa mas n. sp., holotype male (35.5 × 26.4 mm) (ZRC 2015.0005), Gunung Penrissen.