Parathelphusa pareparensis (De Man, 1892 )

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 : 399-402

Parathelphusa pareparensis (De Man, 1892)

( Figs. 17-19 , 20 F-J)

Telphusa celebensis var. pareparensis De Man, 1892: 301 , Pl. 18

Fig. 7e . Potamon celebense var. pareparensis - Roux, 1904: 265. Potamon (Potamonautes) celebensis pareparensis - Rathbun, 1905:

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

Material examined. – Lectotype: male (22.3 x 17.6 mm) ( RMNH D 2587 ), river near Pare-Pare, South Sulawesi, coll. M. Weber, 24 Sep.-6 Oct.1888. Others: 1 male (29.5 x 22.9 mm), 2 females ( ZRC 2000.2570 ), Maros , Kappang Gua Tanette , along subterranean stream, South Sulawesi, coll. L. Deharveng, 8 Jul.1988; 2 males, 5 females ( MZB 1257 ), Sungai Bantimurung , Kab. Maros, South Sulawesi, 5 ° 02'S 119 ° 40'E, coll. M. Siluba, 13 Oct.1986; 1 male, 1 female, 1 juvenile ( MZB. 1267), small river at Anoengga, southeast Sulawesi, coll. not known, 19 Oct 1978; 1 male ( ZRC 2000.2571 ), Gua Salukkan Kallang, South Sulawesi, coll. 7 Aug.1988; 1 male ( ZRC 2000.2572 ), Maros, cave, source of Gua Tanette, near Kappang village , South Sulawesi, coll. D. Rigel, 6 Jul.1988; 1 female ( ZRC 1990.486 ), exact locality unknown, Sulawesi, coll D. Rigal, 16 Jun 1989; 1 female, 1 juvenile ( ZRC 2000.2573 ), Maros, South Sulawesi, coll. L. Deharveng, date not known; 1 juvenile ( ZRC 2000.2574 ), Maros, South Sulawesi, coll. L. Deharveng, date not known; 1 female (33.5 x 25.8 mm) ( ZRC, ex MZB 2002.0011 ), Sumur Jodoh, Cagar Alam Karaenta, Camba, Kabupaten Maros, South Sulawesi, coll. C. Rahmadi, 1 May.2002; 1 female (30.5 x 23.3 mm) ( MZB 0016 ), Gua Assuloang, gallery entrance, Balocci, South Sulawesi, 4 ° 55'46.9"S 119 ° 40'42"E, coll. C. Rahmadi, 17 Aug.2001; 1 female (24.3 x 18.3 mm) ( MZB 0010 ), Gua Sallukan Kallang, Kappang, Kabupaten Maros, South Sulawesi, coll. C. Rahmadi, 11 Aug.2001; 1 female (33.1 x 25.3 mm) ( MZB 0012 ), Gua Assuloang, gallery entrance, Balocci, South Sulawesi, 4 ° 55'46.9"S 119 ° 40'42"E, coll. A. Bedos, 17 Aug.2001.

Diagnosis. – Carapace convex, branchial regions 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 does not reach anterolateral margin, stopping between base of second epibranchial teeth and start of cervical groove. Front sinuous, entire, median point with slight depression; frontal median triangle distinct, dorsal ridge indistinct. Anterolateral margin smooth, external orbital angle broadly triangular, low, outer margin almost straight, about 3.2 times length of inner margin, first and second epibranchial teeth low but distinct, almost continuous with anterolateral margin. Posterolateral regions lined with distinct oblique striae. Suture between thoracic sternites 2 and 3 incomplete, almost straight. Palm of chelipeds slightly inflated, fingers longer than palm. Ambulatory legs long, second pair longest. Dactylus of ambulatory legs long, slender. 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 slender, curved, directed upwards, outer margin gently sinuous along distal two-thirds, proximal part with small cleft; distal part tapering slightly. G2 with well developed distal segment, about 0.5 times length of basal segment.

Distribution. – Known for certainty only from caves as well as rivers and streams in the vicinity of Maros, South Sulawesi.

Remarks. – Telphusa celebensis var. pareparensis was first described by De Man (1892) on the basis of three males and seven females from around Parepare, Sulawesi. He also noted that a young female from Maros corresponds to his variety pareparensis as well. Subsequently Bott (1970c) regarded P. celebensis var. pareparensis as a junior synonym to P. celebensis but apparently, he neither looked at the specimens examined by De Man (1892) nor examined topotypic material. In this study, with the detailed diagnosis and figure of the carapace by De Man (1892) and the examination of a syntype male and topotypic material from around Parepare and Maros, we are certain P. pareparensis is a valid species, and the taxon is hereby resurrected. The syntype male examined in this study is here designated as the lectotype of the species.

The closest congener to Parathelphusa pareparensis is P. celebensis and it belongs to the P. pallida - P. celebensis species complex. Parathelphusa pareparensis is similar to P. celebensis in that the outer edge of the postorbital crista stops at the base of the second epibranchial tooth, the dorsal ridge of the frontal median triangle is indistinct and that the external orbital angle is broadly triangular. Parathelphusa pareparensis shares some similarity with P. pallida in that both their epibranchial teeth are low, almost continuous with the anterolateral margin.

However, examination of a good series of comparative material of P. celebensis and P. pallida from the vicinity of Maros, shows that P. pareparensis differs in several key aspects. Parathelphusa pareparensis differs from P. celebensis and P. pallida in the following characters. Firstly, the fingers of the cheliped of P. pareparensis is longer than the palm compared to both P. celebensis and P. pallida in which the fingers are shorter than the palm. Although variation in the length of fingers relative to palm due to size differences have often been observed in some freshwater crabs, those of P. pareparensis are probably not due to allometric growth. Comparative sized male specimens of all three species of Parathelphusa were examined to ascertain the usefulness of this character. The fingers of P. pareparensis were consistently longer than those of P. pallida and P. celebensis , to the extent that the fingers were always longer than the palm. In this case, the character of fingers longer than palm is useful in differentiating the species. The dactylus of the ambulatory legs of P. pareparensis is also proportionately longer and comparatively more slender than those of both P. celebensis and P. pallida . Thirdly, the outer edge of the postorbital cristae stops between the base of the second epibranchial teeth and the start of the cervical groove, a feature diagnostic for this species. Lastly, the G1 of P. pareparensis is relatively more slender and longer as compared to that of P. celebensis and P. pallida .

The fresh coloration of P. pareparensis is rather striking when compared to the drabber and more uniform colours of typical Parathelphusa species. After a few months in preservative, the recent specimens had the median part of the carapace and most of the ambulatory legs (except for the proximal-most parts) purple, with the rest of the surfaces cream coloured. The pattern is still evident even in freshly preserved specimens ( Fig. 19 ).

Figures

Fig. 17. Parathelphusa pareparensis, lectotype male (22.3 x 17.6 mm) (RMNH D 2587): A, dorsal view; B, frontal view.

Fig. 18. Parathelphusa pareparensis (De Man, 1892), male (29.5 x 22.9 mm, ZRC 2000.2570): A, dorsal view; B, frontal view; C, ventral view.

Fig. 19. Parathelphusa pareparensis (De Man, 1892), young female (25.8 x 19.9 mm) (ZRC 2000.2570), photographed shortly after preservation showing fresh coloration pattern: A, dorsal view; B, dorsal view of carapace; C, frontal view.

Fig. 20. Left G1 and G2. A-E, Parathelphusa possoensis (Roux, 1904), male (27.0 x 20.9 mm, ZRC 2000.1682): 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 pareparensis (De Man, 1892), male (29.5 x 22.9 mm, ZRC 2000.2570): 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. 7. Parathelphusa ceophallus Ng, 1993, holotype male (23.1 x 18.1mm) (RMNH D 42418): A, right dorsal view of carapace; B, frontal view of carapace; C, frontal median triangle; D, anterior thoracic sternum; E, male abdominal segmenst 4-6 and telson; F, left third maxilliped; G, right fourth ambulatory leg; H, left G1 ventral view; I, left G1 dorsal view; J, left G1 distal part, ventral view; K, left G1 distal part, dorsal view; L, left G2 (after Ng, 1993: Figs. 1, 2). Scale bars: A-G = 1.0 mm; H, I, L = 0.5 mm; J, K = 0.25 mm.