Danarma silus ( Davie & Ng, 2013 )

Schubart, Christoph D. & Ng, Peter K. L., 2020, Revision of the intertidal and semiterrestrial crab genera Chiromantes Gistel, 1848, and Pseudosesarma Serène & Soh, 1970 (Crustacea: Brachyura: Sesarmidae), using morphology and molecular phylogenetics, with the establishment of nine new genera and two new species, Raffles Bulletin of Zoology 68, pp. 891-994 : 922-923

Danarma silus ( Davie & Ng, 2013)

( Fig. 13B )

Chiromantes obtusifrons – Paulay et al., 2003: 508; Paulay & Starmer, 2011: 2, 11.

Chiromantes silus Davie & Ng, 2013: 14 ; figs. 3A–C, 4B, 5C, 6C, 7C, 8B, 9C, 13A–E.

Material examined. Holotype male (16.3 × 12.8 mm) ( ZRC 2012.0787 ), Tangulsson , Guam, 10–20 m from shore, 5–8 m elevation, under limestone rocks, coll. G. Paulay, 5 October 1997. Paratypes – 1 male (15.1 × 11.3 mm), 1 female (14.9 × 11.2 mm) ( ZRC 2012.0788 ), same data as holotype ; 1 male (15.7 × 11.7 mm) ( ZRC 2001.0742 ), Hapato Beach , Guam, coll. P.K.L. Ng, 3 August 2001 ; 1 ovigerous female (15.2 × 11.6 mm) (with zoea 1) ( ZRC 2001.0743 ), Hapato Beach , Guam, coll. P.K.L. Ng, 4 August 2001 ; 1 female (15.2 × 11.2 mm) ( ZRC 2000.0573 ), Pago Bay , outside of University of Guam Marine Laboratory, Guam, coll. P.K.L. Ng & C.-H. Wang, 15–18 April 2000 .

Diagnosis. Carapace transversely subovate, ca. 1.3 times broader than long; dorsal carapace, lateral branchial regions markedly swollen; external orbital tooth weakly oblique, forming rounded obtuse angle posteriorly marking widest point of carapace, especially in larger specimens; front ca. 0.65 times carapace width, margin straight or slightly concave in dorsal view, appearing smooth but microscopically granular, with pair of low lateral swellings behind margin; supraorbital margin entire, semicircular; dorsal surface of cheliped carpus conspicuously granular; ambulatory legs relatively short; third ambulatory merus ca. 2.3 times longer than wide; fourth ambulatory merus similar, 2.4 times longer; third ambulatory propodus ca. 2.6 times longer than wide; fourth ambulatory merus ca. 2.3 times; male pleon moderately broad, somite 6 with lateral margins broadly divergent with margins relatively evenly convex, somite 3 width 3.2 times basal width of telson; G1 relatively slender, weakly tapering to broadly convex subdistal shoulder; distally slender, strongly bent to 45° angle; distal chitinous process long, with dorsal margin concave, apically pointed. (After Davie & Ng, 2013: 16).

Colour. “Background colour of carapace typically maroon, with coarse paler orange to yellow-green blotching. Legs speckled with some indication of transverse banding. Legs and chelipeds dorsally reddish brown to dark orange, becoming paler orange in frontal and ventral view. Ocular peduncles speckled similar to carapace; corneas darker.” ( Davie & Ng, 2013: 17, fig. 3A–C).

Remarks. The taxonomy of this species has been treated by Davie & Ng (2013).

Biology. Lives under rocks and in karstic crevices in sparsely vegetated coastal platforms, up to ca. 50 m inland and ca. 10 m elevation ( Paulay & Starmer, 2011: 11; Davie & Ng, 2013: 17).

Distribution. Known only from Guam ( Davie & Ng, 2013).

Figures

Fig. 13. Overall habitus. A, Danarma obtusifrons, male (17.7 × 13.2 mm) (UF-FLMNH 14837), Oahu, Hawaii; B, Danarma silus, holotype male (16.3 × 12.8 mm) (ZRC 2012.0787), Guam; C, Danarma eurymerus, holotype male (18.7 × 14.8 mm) (NMNS-7028-002), Lanyu Island, Taiwan; D, Danarma garfunkel, holotype male (17.0 × 13.0 mm) (QM), Greta Beach, Christmas Island; E, Cristarma eulimene, male (22.2 × 17.2 mm) (ZRC 1968.1.22.2), Inhaca Island, Mozambique; F, Cristarma ortmanni, male (20.0 × 15.5 mm) (ZRC 1968.1.22.1), Inhaca Island, Mozambique; G, Trapezarma angolense, neotype male (39.3 × 32.7 mm) (SMF-ZMG 635), Benguella, Angola; H, Platychirarma buettikoferi, paralectotype male (10.0 × 8.7 mm) (SMF-ZMG 636), Fisherman Lake, Liberia; I, Platychirarma buettikoferi, lectotype male (14.1 × 11.6 mm) (RMNH D 148), Liberia; J, Platychirarma buettikoferi, male (12.6 × 10.4 mm) (ZRC 2015.0298), Cameroon.