Parathelphusa linduensis ( Roux, 1904 )

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 : 403

Parathelphusa linduensis ( Roux, 1904)

( Figs. 22 , 23 F-J)

Potamon (Potamonautes) celebensis (part) - Schenkel, 1902: 528,

Pl. 10 Fig. 9 , 13a Potamon celebense var. linduensis Roux, 1904: 562 , Fig. A. Parathelphusa (Mesotelphusa) pallida (part) - Bott, 1970c: 128, Pl.

24 Fig. 83-84.

Material examined. – Lectotype: male (24.8 x 19.7 mm) ( NMB 23 VIIa), Lake Lindu , Central Sulawesi, 1 ° 18'S 120 ° 05'E, coll. Gesch & Sarasin, 1904 . Paralectotypes: 1 male ( NMB 23 VIIa), same data as lectotype ; 2 males, 2 females ( NMB 23 VII), same data as lectotype .

Diagnosis. – Carapace convex and inflated, dorsal surfaces smooth; cervical groove shallow, but distinct; H-shaped central depression pronounced. Epigastric and postorbital cristae continuous, sharp, subparallel to frontal margin; outer edge of cristae not reaching anterolateral margin, stopping when it meets cervical groove. Front sinuous, entire, median point with distinct depression; frontal median triangle distinct, broad, low, dorsal ridge absent. Anterolateral margin smooth, external orbital angle broadly triangular, outer margin almost straight, about 2.5 times length of inner margin, first and second epibranchial teeth very low, almost continuous with anterolateral margin. Posterolateral regions smooth. Suture between thoracic sternites 2 and 3 incomplete, almost straight. Suture between thoracic sternites 3 and 4 distinct, sinuous. Palm of chelipeds slightly inflated, fingers shorter than palm. Ambulatory legs relatively short, second pair longest. Dorsal margin of merus slightly cristate, without distinct subterminal spine. Male abdomen reaching imaginary line joining anterior edges of cheliped bases, T-shaped, segment 6 distinctly longer than segment 7; lateral margins of segment 7 gently concave; lateral margins of segment 6 subparallel, gently sinuous. G1 relatively stouter, relatively curved, directed upwards, outer margin sinuous along distal two-thirds, proximal part with slight cleft; distal part tapering. G2 with well developed distal segment, about 0.5 times length of basal segment.

Distribution. – Lake Lindu, Central Sulawesi.

Remarks. – Roux (1904) described Potamon celebense var. linduensis from five males and seven females from Lake Lindu which Schenkel (1902) had regarded as Potamon celebense . Bott (1970c) subsequently examined two syntype males and a female but did not designate a lectotype. In this study, the male measuring 24.8 by 19.7 mm (NMB 23 VIIa) is designated as the lectotype.

Parathelphusa linduensis in this study is regarded as a valid species and not a junior synonym of P. pallida as by Bott (1970c). Parathelphusa linduensis differs from P. pallida in the following characters. The carapace for P. linduensis is relatively more inflated than that of P. pallida , particularly in the gastric regions ( Fig. 22A vs. Figs. 12A , 13A ). The outer edge of the postorbital cristae of P. linduensis stops where it meets the cervical groove, while the outer edge of the postorbital cristae of P. pallida stops just before the anterolateral margin, between the bases of the first and second epibranchial teeth ( Fig. 22A vs. Figs. 12A , 13A ). The frontal median triangle for P. linduensis is broad and low with the dorsal ridge being absent while the frontal median triangle for P. pallida i s distinct with all the lateral ridges and the dorsal ridge being sharp and distinct ( Fig. 22B vs. Figs. 12B , 13B ). For P. linduensis , the anterolateral margin is smooth compared to P. pallida which is finely granulated. The suture between thoracic sternites two and three is incomplete for P. linduensis while the suture between sternites two and three for P. pallida is complete. The suture between thoracic sternites three and four is distinct and sinuous in P. linduensis while in P. pallida this suture is absent. Lastly, the G1 for P. linduensis is relatively more curved in the distal half as compared to that for P. pallida which is relatively straighter ( Fig. 23F, G vs. Fig. 14F, G ).

Figures

Fig.22. Parathelphusa linduensis (Roux, 1904), lectotype male (24.8 x 19.7 mm, NMB 23VIIa):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. 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. 13. Parathelphusa pallida (Schenkel, 1902), female (NMB 23 Ia) (lectotype of Potamon (Potamonautes) celebensis var.annulipes Schenkel, 1902): A, dorsal view; B, frontal view; C, ventral view.

Fig. 12. Parathelphusa pallida (Schenkel, 1902), lectotype male (23.9 x 18.3 mm, NMB 23VIb): 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.