Terrathelphusa cerina, 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: 336

publication ID

http://dx.doi.org/10.11646/zootaxa.3946.3.2

publication LSID

lsid:zoobank.org:pub:24E2F41D-89BF-473F-ACE0-ED951BCB2699

persistent identifier

http://treatment.plazi.org/id/03DF87F3-FFCD-6E7B-FF4F-FBA9D7B72F3E

treatment provided by

Plazi

scientific name

Terrathelphusa cerina
status

n. sp.

Terrathelphusa cerina   n. sp.

( Figs. 5 View FIGURE 5 A –H, 6 A –E, 11 E, F)

Material examined. Holotype: male (24.7 × 19.3 mm) ( ZRC 2015.0003), damp riverbank of Sungai Sebayak, Gunung Singai, Bau, Sarawak, 1 O 30 ’ 17.1 ”N 110 O 10 ’ 40.1 ”E, 66 m asl, coll. J. Grinang et al., 31 March 2012. Paratype: 1 male (30.0 × 22.8 mm), 2 females (larger 31.0 × 26.2 mm) ( ZRC 2014.0842), data same as holotype.

Diagnosis. Carapace broader than long, swollen, surface convex, very smooth; cervical grooves broad, deep; epigastric cristae high separated by deep epigastric groove; H-groove deep, long almost confluent with cervical grooves; epibranchial tooth indiscernible, anterolateral, frontal regions appearing compressed, supraorbital margin almost parallel with frontal margin; epistome median lobe blunt to pointed ( Fig. 5 View FIGURE 5 A –C). Male abdomen with elongated somite 6, lateral margins gently concave ( Fig. 5 View FIGURE 5 D). Ischium of third maxilliped rectangular, about 2.0 times maximum width ( Fig. 5 View FIGURE 5 E). Ambulatory legs smooth, relatively slender, second pair longest, length of fourth merus about 3.9 times width ( Fig. 5 View FIGURE 5 F). Cheliped carpus rugose, without granules ( Fig. 5 View FIGURE 5 G, H), inner angle with acutely triangular tooth; gap between fingers of major chela relatively narrow ( Fig. 5 View FIGURE 5 A). G 1 gently curving outwards; terminal segment cone-shaped, tapered, gently curving upwards, about 0.3 times length of subterminal segment ( Fig. 6 View FIGURE 6 A, B, D, E). Distal segment of G 2 relatively long, about 0.7 times length of basal segment ( Fig. 6 View FIGURE 6 C).

Life colour. Individuals are bright yellowish overall ( Fig. 11 View FIGURE 11 E, F).

Variation. The paratypes agree very well with the holotype male except in few non-sexual characters. The cervical grooves are proportionately broader and the ambulatory legs relatively longer in larger specimens.

Habitat. Swampy floodplains in slightly disturbed lowland primary forest. Lives in shallow burrows less than 1 m depth, with dense debris in the soil.

Etymology. The name is derived from the Greek kerinos for “yellowish wax colour”, alluding to the appearance of the species in life. The name is used as a noun in apposition.

Remarks. Terrathelphusa cerina   n. sp., is distinguished from T. kuchingensis   and the other three new species by a combination of characters. The carapace is relatively less swollen and convex ( Fig. 5 View FIGURE 5 B) than in its congeners, and the epibranchial tooth is indiscernible ( Fig. 5 View FIGURE 5 A –C). In comparison to its closest congener, T. kuchingensis   , the G 1 subterminal segment of T. cerina   n. sp. is distinctly curved outwards, with the tip of the terminal segment relatively blunter ( Fig. 6 View FIGURE 6 A, B, D, E) (subterminal segment is less prominently curved outwards, with the terminal segment more pointed in T. kuchingensis   , Fig. 2 View FIGURE 2 A, B, D, E). Live specimens of T. cerina   n. sp. are more similar to T. mas   n. sp. but the latter species is of an even more striking yellow colour ( Fig. 11 View FIGURE 11 E, F, I, J).

ZRC

Zoological Reference Collection, National University of Singapore