Geothelphusa lili, Chen & Cheng & Jhy-Yun & Shy, 2005

Chen, Wen-Jou, Cheng, Jin-Hua, Jhy-Yun & Shy, 2005, On Two New Species Of Freshwater Crabs (Crustacea: Decapoda: Brachyura: Potamidae) From Southern Taiwan, Raffles Bulletin of Zoology 53 (1), pp. 103-110 : 104-107

Geothelphusa lili , new species

( Figs. 2C,D , 6 )

Material examined. – Holotype - male (20.1 by 15.5 mm)( NTOU F000701 ), Laii, Pingtung county, coll. W.J. Chen, 26 Jul. 2000.

Paratypes – 4 females (largest female 18.7 by 14.9 mm)( NTOU F000701 ), same data as holotype ; 2 males, 2 females ( NTOU F001001 ), Laii, Pingtung county, coll. W.J. Chen & C.F. Tseng, 15 Oct. 2000 .

Others – 1 male (18.5 by 15.1 mm)( NTOU F010101 ), Laii , Pingtung county, coll. W.J. Chen & C.F. Tseng, 1 Jan. 2001 . 1 male, 3 females (largest female 20.0 by 15.4 mm) ( SYSU F01122802 ), Machia , Pingtung county, coll. W.J. Chen, 28 Oct. 2001 . 2 males, 1 female (largest male 18.3 by 14.1 mm) ( SYSU F02010601 ), Sandimen , Pingtung county, coll. W.J. Chen, 6 Jan. 2002 . 2 males, 1 female (largest male 20.2 by 16.1mm) ( SYSU F010217 ), Taiwu , Pingtung county, coll. W.J. Chen & C.F. Tseng, 17 Feb. 2001 .

Diagnosis. – Carapace with fine pits, width and length about 2.3 and 1.8 times depth; width about 1.3 times length; frontal width about 0.3 times carapace width (Table 1). Gastric region smooth, anterolateral and posterolateral regions with striae. Postorbital crista faint, orbital and frontal region gently concaved, divided into 2 lobes. Anterolateral crista distinct, epibranchial tooth absent, lined with small granules. Cervical groove shallow, faint. H-shaped gastric groove is distinct. Posterior epistomal margin sinuous, median lobe not acutely triangular.

Abdomens of male and female with 7 distinct segments (including telson); in male, length of telson 0.8 times width, longer than 6th, as in female (Table 2). Distance between tip of male abdomen and anterior margin of thoracic sternite 4 about 0.9 times of sternites 1-3.

Chelipeds unequal, in large chela, outer surface of palm smooth, upper margin length 0.7 times length of dactylus, height 0.6 times length of chela (Table 3). Length of dactylus 0.7 times that of chela. Fingers forming obliquely triangular gape when closed, with faint cutting teeth. Carpus of large chela with 1 large spine on inner, upper surface and a subequal one below it. Inner and outer surfaces of merus with fine striae.

Ambulatory legs slender, with simple setae; second longest, last shortest. Second ambulatory leg about 1.8 times carapace length. In last 2 segments of right second ambulatory leg, width of propodus 0.4 times length, 0.4 times the length of dactylus; length of propodus 0.8 times dactylus (Table 4). Dactylus and propodus with a row of 3 - 9 spines on each of 4 longitudinal margins.

G1 subterminal segment straight; outer proximal margin with faint tooth and inner proximal margin dilated, both proximal margins with plumose setae, especially on inner proximal margin ( Fig. 6 ). Terminal segment of G1 straight, slightly curved outwards, 4-5 rings of distal scales are distributed and subterminal has sparsely small spines ( Figs. 4A, B ). Total length of G1 5.5 times of terminal segment length, 3.0 times of subterminal segment width. Terminal segment length of G1 2.8 times of its width, synovial membrane length 4.6 times of its width ( Fig. 4A ). Distal segment of G2 straight, flat, directed upwards, length 0.2 times of total length ( Fig. 6D ).

Coloration. – Carapace and upper surface of ambulatory legs dark brown, but posterior half of carapace slightly dark green. Dorsal part of outer and inner surfaces of cheliped purple ( Figs. 2C, D ).

Habitat. – Lives under boulders near springs.

Etymology. – The species is named after its type locality and the name is used as a noun in apposition.

Remarks. – This species is allied to G. ferruginea Shy, Ng & Yu, 1994 , but it can be distinguished by the following aspects: in G. lili , the G1 synovial membrane length is 4.6 times its width, but 3.8 times in G. ferruginea (Shy, Ng & Yu, 1994: 783) ; in G. lili , terminal segment of G1 straight and slightly curves outwards but in G. ferruginea it curves inwards founds the median part of the sternum ( Figs. 4A, C ; 6B, C ); in G. lili , the total length of the G1 is 5.5 times the terminal segment length, but 6.0 times in G. ferruginea (Shy, Ng & Yu, 1994: 783) .

Distribution. – Northern Pingtung county, southern Taiwan (present study).

Figures

Fig. 2, A-B: Geothelphusa shernshan, new species. Holotype male, 29.5 by 22.5 mm (NTOU F000101). C-D: G. lili, new species. Holotype male, 20.1 by 15.5 mm (NTOU F000701). A, C: dorsal view; B, D: frontal view.

Fig. 6, Geothelphusa lili, new species. Holotype male, 20.1 by 15.5 mm (NTOU F000701). A: carapace; B: ventral view of right G1; C: dorsal view of right G1; D: ventral view of right G2; d: ventral view of right G1 terminal segment. Scale: a – c = 1 mm, d = 0.1 mm, e = 1.5 mm.

Fig. 4, A, B: Geothelphusa lili, new species. Paratype male, 18.5 by 15.1 mm (NTOU F010101). C, D: G. ferruginea. Paratype male, 20.8 by 16.5 mm (NTOU F020601). All dorsal view of G1; B, D: terminal segment; A, C: synovial membrane. Scale, A, C = 1 mm; B, D: 100 m.