Parathelphusa crocea ( Schenkel, 1902 )

Ng, Oliver K. S. Chia Peter K. L., 2006, The Freshwater Crabs Of Sulawesi, With Descriptions Of Two New Genera And Four New Species (Crustacea: Decapoda: Brachyura: Parathelphusidae), Raffles Bulletin of Zoology 54 (2), pp. 381-428 : 402

Parathelphusa crocea ( Schenkel, 1902)

( Figs. 21 , 23 A-E)

Potamon (Potamonautes) celebense var. croceum Schenkel, 1902: 350 .

Potamon (Potamonautes) celebensis croceus - Rathbun, 1905: 199.

Parathelphusa (Mesotelphusa) celebensis (part) - Bott, 1970c: 127.

Material examined. – Holotype: male (26.3 x 21.3 mm) ( NMB 23 IIIa), around Ussu, South Sulawesi, coll. Gesch & Sarasin, 1901. Others: 2 males, 1 female ( ZRC 2000.2568 ), Kabupaten Maros , Pattuang , South Sulawesi, coll. M. Kottelat, 7 Jun.1988; 2 males, 4 females ( ZRC 2000.2569 ), Kabupaten Maros , Leang Leang , South Sulawesi, coll. M. Kottelat, 7 Jun.1988; 2 males ( MZB 1184 ), Taman Wisata , Bantimurung , Kabupaten , Maros , South Sulawesi, 5 ° 02'S 119 ° 40'E, coll. M. Siluba, 8 Oct.1982.

Diagnosis. – Carapace convex, dorsal surfaces smooth; cervical groove shallow, but distinct, almost reaching anterolateral margin; H-shaped central depression pronounced. Epigastric and postorbital cristae continuous, sharp, subparallel to frontal margin; outer edge of cristae reaches anterolateral margin, stopping at base of second epibranchial teeth. Front almost straight, entire; frontal median triangle distinct, height of frontal median triangle relatively higher, dorsal ridged margin indistinct. Anterolateral margin smooth, external orbital angle triangular, low, outer margin almost straight, about 2.5 times length of inner margin, first and second epibranchial teeth low almost confluent with anterolateral margin. Posterolateral regions lined with distinct oblique striae. Suture between thoracic sternites 2 and 3 complete, almost straight, suture between sternites 3 and 4 absent. Palm of chelipeds slightly inflated, fingers shorter than palm. Ambulatory legs relatively short, second pair longest, dactylus of last ambulatory leg, relatively shorter and broader. Dorsal margin of merus slightly cristate, without distinct subterminal spine. Male abdomen reaching imaginary line joining anterior edges of cheliped bases, Tshaped, segment 6 distinctly longer than segment 7; lateral margins of segment 7 gently concave; lateral margins of segment 6 subparallel, relatively straight. G1 slender, relatively sinuous, directed upwards, outer margin gently sinuous along distal two-thirds, proximal part with distinct cleft; distal part tapering, directed inwards. G2 with well developed distal segment, about 0.7 times length of basal segment.

Distribution. – Around the vicinity of Ussu and Maros, South Sulawesi.

Remarks. – Potamon (Potamonautes) celebense var. croceum was described from a single male specimen from the vicinity of Ussu by Schenkel (1902). Bott (1970c) regarded it as a junior synonym of P. celebensis . However, there are enough key differentiating characters to regard P. crocea as a valid species although both taxa occur in South Sulawesi.

The frontal median triangle of P. crocea is relatively higher compared to the frontal median triangle of P. celebensis ( Fig. 21B vs. Figs. 8B , 9B , 10B , 11B ). Parathelphusa crocea has an orbital angle that is lower and more broadly triangular compared to that of P. celebensis ( Fig. 21A vs. Figs. 8A , 9A , 10A , 11A ). The first and second epibranchial teeth of P. crocea are almost confluent with the anterolateral margin while the first and second epibranchial teeth of P. celebensis are low but distinct ( Fig. 21A vs. Figs. 8A , 9A , 10A , 11A ). The suture between thoracic sternites two and three of P. crocea is complete while the suture for P. celebensis is incomplete. One distinguishing character is that the dactylus of the last pair of ambulatory leg of P. crocea ( Fig. 21A ) which is relatively shorter and broader than that of P. celebensis ( Figs. 10A , 11A ). Lastly, the G1 of P. crocea is relatively more sinuous and it possess a distinct cleft in the proximal part ( Fig. 23 A-D) compared to that of P. celebensis which is relatively straighter and does not possess a clear cleft in the proximal part ( Fig. 14 A-D). Parathelphusa crocea should thus be regarded as a valid species, distinct from the sympatric P. celebensis .

Figures

Fig.21. Parathelphusa crocea (Schenkel, 1902), holotype male (26.3 x 21.3 mm, NMB 23IIIa):A, dorsal view; B, frontal view; C, ventral view.

Fig. 23. Left G1 and G2. A-E, Parathelphusa crocea (Schenkel, 1902), holotype male (26.3 x 21.3 mm, NMB 23IIIa): A, G1 ventral view; B, G1 dorsal view; C, G1 distal part, ventral view; D, G1 distal part, dorsal view; E, G2. F-J, Parathelphusa linduensis (Roux, 1904), male (24.8 x 19.7 mm, NMB 23VIIa): F, G1 ventral view; G, G1 dorsal view; H, G1 distal part, ventral view; I, G1 distal part, dorsal view; J, G2. Scale bars = 1.0 mm.

Fig. 8. Parathelphusa celebensis (De Man, 1892), lectotype male (18.8 x 15.2 mm, RMNH D 2385): A, dorsal view; B, frontal view; C, ventral view.

Fig. 9. Parathelphusa celebensis (De Man, 1892), paralectotype female (26.6 x 20.9 mm) (RMNH D 2385): A, dorsal view of carapace; B, frontal view.

Fig. 10. Parathelphusa celebensis (De Man, 1892), male (33.3 x 26.1 mm, NMB 23IVa): A, dorsal view; B, frontal view; C, ventral view.

Fig. 11. Parathelphusa celebensis (De Man, 1892), 1 male (33.3 x 26.1 mm) (lectotype of Potamon (Potamonautes) celebense var. immaculata Schenkel, 1902): A, dorsal view; B, frontal view; C, ventral view.

Fig. 14. G1 and G2. A-E, Parathelphusa celebensis (De Man, 1892), male (33.3 x 26.1 mm, NMB 23IVa): A, left G1 ventral view; B, left G1 dorsal view; C, left G1 distal part, ventral view; D, left G1 distal part, dorsal view; E, left G2. F-J, Parathelphusa pallida (Schenkel, 1902), lectotype male (23.9 x 18.3 mm, NMB 23VIb): F, right G1 dorsal view; G, right G1 ventral view; H, right G1 distal part, dorsal view; I, right G1 distal part, ventral view; J, G2. Scale bars = 1.0 mm.