Terrathelphusa mas, 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: 341-344

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Terrathelphusa mas

n. sp.

Terrathelphusa mas   n. sp.

( Figs. 9 View FIGURE 9 A –H, 10 A –E, 11 I, J) Material examined. Holotype: male (35.5 × 26.4 mm) ( ZRC 2015.0005), open green golf course, Borneo Highlands Resort, Gunung Penrissen, Kuching, Sarawak, 1 O07’ 43.8 ”N 110 O 13 ’07.3”E, 852 m asl, coll. J. Grinang et al., 16 September 2013. Paratype: 2 females (larger 26.3 × 20.4 mm) (SBC.C.00374– 75); 1 female ( ZRC 2014.0840); data same as holotype.

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. 9 View FIGURE 9 A –C). Male abdomen with elongated somite 6, lateral margins gently concave ( Fig. 9 View FIGURE 9 D). Third maxilliped ischium rectangular, about 2.1 times maximum width ( Fig. 9 View FIGURE 9 E). Ambulatory legs smooth, relatively slender, length about 4.4 times width ( Fig. 9 View FIGURE 9 F). Cheliped carpus rugose, without granules ( Fig. 9 View FIGURE 9 G, H), inner angle with narrower, acutely triangular tooth; gap between fingers of major chela conspicuously wide ( Fig. 9 View FIGURE 9 A). G 1 distinctly curving outwards; terminal segment cone-shaped, tapered, gently curving upwards to tip, about 0.3 times length of subterminal segment ( Fig. 10 View FIGURE 10 A, B, D, E). Distal segment of G 2 relatively long, about 0.8 times length of basal segment ( Fig. 10 View FIGURE 10 C).

Life colour. Body and appendages are bright golden yellow ( Fig. 11 View FIGURE 11 I, J).

Variation. The paratypes agree well with the holotype male except for variations in a few characters. In the larger specimens, the ambulatory legs are relatively longer and the cervical grooves are somewhat broader than in smaller specimens.

Habitat. The species is sympatric with T. aglaia   n. sp., at high elevations on Gunung Penrissen, but it absent at low elevations.

Etymology. Derived from the Iban word mas   for gold alluding to the golden appearance of the new species. The name is used as a noun in apposition.

Characters T. aglaia   T. cerina   T. kuchingensis   T. kundong   T. loxophthalma   * T. mas   T. ovis   * T. telur*   Third Length of ischium Length of ischium Length of ischium Length of Length of ischium Length of ischium Length of ischium Length of maxilliped about 1.9 times about 2.0 times about 1.8 times ischium about about 1.8 times about 2.1 times about 1.6 times ischium about

maximum width maximum width maximum width 1.9 times maximum width maximum width maximum width 1.5 times

maximum width maximum width Remarks. Terrathelphusa mas   n. sp., can be distinguished from T. kuchingensis   and the other species being described by a combination of characters: inner angle of carpus having a narrow and acutely triangular tooth ( Fig. 9 View FIGURE 9 A) (versus broad and acutely triangular tooth in T. kuchingensis   ( Fig. 1 View FIGURE 1 A), T. aglaia   n. sp. ( Fig. 3 View FIGURE 3 A) and T. cerina   n. sp. ( Fig. 5 View FIGURE 5 A), and broadly triangular tooth in T. kundong   n. sp. ( Fig. 7 View FIGURE 7 A); and the G 1 is distinctly curving outwards ( Fig. 10 View FIGURE 10 A, B, C, D) (versus gently curving outwards in others, Figs. 2 View FIGURE 2 A, B, D, E; 4 A, B, D, E; 6 A, B, D, E; 8 A, B, D, E). Terrathelphusa   species from the Kuching region differ from taxa in the northern region viz. T. loxophthalma   , T. ovis   and T. telur   as summarised in Table 1.


Zoological Reference Collection, National University of Singapore