Lepidothelphusa cognettii ( Nobili, 1903 )

Grinang, Jongkar & Ng, Peter K. L., 2015, Taxonomy of the semiterrestrial crab Lepidothelphusa cognettii (Nobili, 1903) (Crustacea: Decapoda: Brachyura: Gecarcinucidae), with descriptions of five new species from Sarawak, Malaysia, Borneo, Raffles Bulletin of Zoology 63, pp. 564-582 : 565-568

publication ID	https://doi.org/ 10.5281/zenodo.5386711
publication LSID	lsid:zoobank.org:pub:BAA493D3-8195-417B-ABD8-A36D3FD90533
persistent identifier	https://treatment.plazi.org/id/039387F0-C667-FF97-AEC8-FE790F0DFCE4
treatment provided by	Valdenar
scientific name	Lepidothelphusa cognettii ( Nobili, 1903 )
status

Treatment

Lepidothelphusa cognettii ( Nobili, 1903) View in CoL

( Figs. 1A–I View Fig , 2A–E View Fig , 13A, B View Fig )

Potamon (Geotelphusa) cognettii Nobili, 1903: 15 .

Potamon (Geotelphusa) cognettii – Rathbun, 1905: 214.

Parathelpusa (Lepidothelphusa) cognettii – Colosi, 1920: 24 (part).

Para-Lepidothelphusa cognetii (sic) – Balss, 1937: 174 (list).

Lepidothelphusa cognettii View in CoL – Bott, 1970: 55 (part); Ng & Grinang, 2004: 309 (part).

Lepidothelphusa cognetti (sic) – Ng, 2004: 319 (part); Ng & Yeo, 2007: 108 (part); Ng et al., 2008: 67; Cumberlidge et al., 2009: appendix 1 (part).

Material examined. 3 males (largest 12.2 × 10.2 mm) ( ZRC 2015.0601 View Materials ) , 2 females (larger 10.7 × 8.9 mm) ( ZRC 2015.0602 View Materials ) , 4 males (largest 11.6 × 10.0 mm) (SBC.C.00378–81), Batu Panggah Trail , Gunung Penrissen, Kuching, Sarawak, coll. J Grinang et al., 3 April 2013 ; 9 males (largest 12.0 × 10.2 mm), 1 ovigerous female (10.2 × 8.6 mm) (SBC.C.00382–90), Batu Panggah Trail, Gunung Penrissen, Kuching, Sarawak, coll. J Grinang et al., 7 July 2014 ; 1 male (11.2 × 9.1 mm) (SBC.C.00391), Batu Panggah Trail , Gunung Penrissen, Kuching, Sarawak, coll. WC Lou, 28 July 2012 ; 1 female (10.0 × 8.9 mm) ( ZRC 2015.0603 View Materials ), road to Borneo Highland Resort, Gunung Penrissen, Kuching, Sarawak, coll. PKL Ng, 16 September 2013 ; 7 males (largest 10.5 × 9.6 mm) (SBC.C.00448–54); 5 females (largest 10.4 × 9.2 mm) (SBC.C.00455–59), 7 juveniles (SBC.C.0060–66), Kalimantan Trail , Gunung Penrissen, Kuching, Sarawak, coll. J Grinang et al., 10 September 2015 .

Diagnosis. Carapace quadrate, surface relatively flat, smooth, anterolateral margins smooth; antero- and posterolateral regions slightly rugose; epibranchial tooth undiscernible; external orbital tooth with outer margin concave, smooth; epigastric and postorbital cristae distinct, margins serrated; cervical and H-grooves shallow, not confluent ( Fig. 1A, B, D View Fig ); ischium of third maxilliped rhomboidal, much longer than broad, sulcus undiscernible ( Fig. 1F View Fig ); inner margin of merus of chelipeds with large, expanded serrated projection, projection prominent in large male ( Fig. 1G View Fig ); carpus of chelipeds smooth, inner angle with broadly triangular tooth ( Fig. 1A View Fig ); fingers of adult major male chela strongly gaping ( Fig. 1H, I View Fig ); ambulatory legs relatively long, merus of fourth ambulatory legs subequal to length of carapace ( Fig. 1A, E View Fig ); male abdomen triangular, somite 6 width and length subequal, subequal to length of telson ( Fig. 1C View Fig ); G1 relatively stout, sinuous, gently curving outwards; terminal segment gently curving outwards ( Fig. 2A, B, D, E View Fig ); G2 with relatively long distal segment, about half length of basal segment ( Fig. 2C View Fig ).

Colour. In life, the species is almost cream-white, light yellow anterior regions and chelipeds, light blue posterior regions. Females are generally duller in coloration ( Fig. 13A, B View Fig ).

Remarks. Bott (1970: 56) noted that he had one “ paratype ” male from Bidi (Museum Turin catalogue number 1943), and he figured this specimen ( Bott, 1970: pl. 7 figs. 69–72, pl. 27 fig. 31). However, this specimen is not a paratype. Nobili (1903: 15) had described this species from two males and one female collected by Robert Shelford from Mount Penrissen and made no mention of any material from Bidi. Colosi (1920: 24) listed specimens from Penrissen as well as pair of specimens from Bidi, so the latter material must have been sent to the Turin Museum after Nobili (1903) described the species. The second author has tried to contact the curators and management of the Turin Museum on several occasions to obtain the types. In the early part of this century, the material was being moved but as of today, the museum has suspended all research activities and the collection is no longer accessible (Franco Andreone, in letter, March 2015). Although we have not managed to obtain the type material for this study, considering the restricted distributions of the species now studied, and the material we have obtained from Mount Penrissen is from the type locality, in areas Shelford himself would have collected, we are confident our specimens represent the true Lepidothelphusa cognettii . They agree in all respects with the descriptions by Nobili (1903) and Colosi (1920). The authors also have additional specimens from Bidi collected at the same time as the Colosi material – they are clearly referable to L. limau , new species, instead (see later). Examining the figures of Bott (1970: pl. 7 figs. 69–72, pl. 27 fig. 31), they also agree well with what is described here as L. limau , notably in the carapace shape and structure of the G1. As the reports of this species by Ng (2004), Ng & Grinang (2004), Ng & Yeo (2007), Ng et al. (2008) and Cumberlidge et al. (2009) and Klaus et al. (2009) include or use the Bidi location, all these records also include L. limau . Although there is a second species known from Bau ( L. flavochela , new species), this taxon is easily distinguished by the structure of its carapace and gonopods (see discussion for this species).

Lepidothelphusa cognettii s. str. can be distinguished from its congeners by a combination of characters: carapace distinctly square and flat ( Fig. 1A, B View Fig ) (versus carapace relatively less square and rugose in L. limau , new species ( Fig. 5A, B View Fig ); L. loi , new species ( Fig. 7A, B View Fig ); and L. padawan , new species ( Fig. 9A, B View Fig )), the gap between fingers of adult major chela is conspicuously wide ( Fig. 1H View Fig ) (versus gap between fingers of major chela is relatively narrow in L. flavochela , new species ( Fig. 3G View Fig ); and L. sangon , new species ( Fig. 11H View Fig )), and the G1 is relatively slender ( Fig. 2A, D View Fig ) (versus G1 stout in L. flavochela ( Fig. 4A, D View Fig ); L. limau ( Fig. 6A, D View Fig ); L. loi ( Fig. 8A, D View Fig ); L. sangon ( Fig. 12A, D View Fig )). In the form and shape of the G1, notably in the curving terminal segment, L. cognettii s. str. is similar to L. flavochela and L. padawan . In L. cognettii s. str., the G1 is gently curving outwards ( Fig. 2A, B, D, E View Fig ) but in L. padawan , it is more curving outwards ( Fig. 10A, B, D, E View Fig ). The G1 of L. cognettii s. str. is relatively slender ( Fig. 2A, B, D, E View Fig ) while in L. flavochela it is distinctly stouter ( Fig. 4A, B, D, E View Fig ). Other differences between L. cognettii s. str. and congeners are treated in the general discussion.

All fresh specimens of both species were collected from sandstone outcrops and non-cave systems. This indicates that the Bidi specimens examined by the previous authors might also have been collected from Kampung Peros in Krokong, Bau (type locality of L. limau ), which is only about 2 km from the limestone area of Bidi (see discussion for L. limau ). Certainly, they are not known from limestone formations or inside the Bidi caves (see also Ng, 1989; Ng & Yussof, 1990; Ng & Grinang, 2014).

Habitat. The habitat of the species is moist rock crevices and leaf litter in shaded springs. The habitat is a primary dipterocarp forest with sandstone substrate and the elevation ranges from 200 m to 1200 m above sea level. The habitat appears to be highly localised. Of the known Lepidothelphusa species , L. cognettii s. str., is the only one known from such high altitudes.