Hephthopelta lugubris Alcock 1899
Creators: name: Ng, Peter K. L.
name: Castro, Peter
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Chasmocarcinidae
Hephthopelta
Hephthopelta lugubris

description: Hephthopelta lugubris Alcock, 1899
(Figs. 10 A‒H; 24A; 31A, B; 40E, F; 42G; 52A; 59A, B; 71; 87A; 91A)
Hephthopelta lugubris Alcock, 1899: 77, pl. 4, figs. 2, 2a, 2b [type localilty: Andaman Sea]; 1900: 327 [Andaman Sea].— Tesch 1918: 233 [in key].— Serène 1964a: 240 [in list], 241, 242 [in key]; 1968: 92 [in list].—Ng et al. 2008: 76 [in list].? Hephthopelta sp.— Clavier et al. 1996: 20, 40 [Fiji].
Type material (not examined). Holotype: female (8.0 × 8.0 mm), Andaman Sea, 897 m (depository unknown, possibly in the Zoological Survey of India, Calcutta; see Alcock 1899: 77).
Material examined. Western Australia. RV Southern Surveyor: 1 male (7.9 × 8.3 mm) (NMV J61081) [“ Chasmocarcinops, Det. A. McCallum 2009 ”], Leveque L 273 transect, 14° 33°04”S, 121°15’22”E to 14°33’35”S, 121°16’34”E, 1021‒1023 m, D.J. Bray coll., 03.07.2007; 1 male (6.8 × 7.3 mm), 1 ovigerous female (6.3 × 6.6 mm) (NMV J61083) [“ Chasmocarcinops, Det. A. McCallum 2009 ”], Mermaid L24 transect, 16°38’04”S,119°09’13”E to 16°38’46”S,119°08’02”E, 987‒990 m, M.F. Gomon coll., 17.06.2007.
Papua New Guinea. BIOPAPUA: 1 female (8.9 × 9.6 mm) (ZRC 2015.261), 1 female (9.8 × 10.9 mm) (MNHN-IU- 2011-2657), Open Bay, stn CP3667, 04°40’S, 151°34’E, 670–921 m, 23.09.2010; 1 female (7.1 × 7.7 mm) (MNHN-IU- 2011-2522), off Mambare Bay, stn CP3729, 07°52’S, 148°03’E, 575–655 m, 0 8.10.2010.
Solomon Islands. SALOMONBOA 3: 1 male (10.1 × 11.7 mm), 1 ovigerous female (8.6 × 9.3 mm) (ZRC 2015.262), 1 male (8.3 × 9.1 mm) (MNHN-IU-2013-9040), Savo, stn CP2777, 09°12’S, 160°55’E, 706–722 m, 12.09.2007.—SALOMON 1: 1 male (7.3 × 7.8 mm) (MNHN-IU-2013-9037), stn CP1750, 09°16’S, 159°55’E, 693–696 m, 25.09.2001.
New Caledonia. HALIPRO 1: 1 female (MNHN-IU-2013-9453), eastern coast, stn CP867, 21°26.155’S, 166°18.174’E, 720–950 m, 22.03.1994.
Fiji. MUSORSTOM 10: 1 male (6.3 × 6.5 mm) (MNHN-IU-2013-9028), Viti Levu, stn DW1356, 17°50.3’S, 178°48.0’E, 203–208 m, 12.08.1998; 1 female (MNHN-IU-2013-9058), Bligh Water, Fiji, stn CP1332, 16°56.2’S, 178°7.9’E, 640–687 m, 0 8.08.1998.
Diagnosis. Carapace (Fig. 10 A, D–H) subtrapezoidal, globose, tomentose, 1.0‒1.1 wider than long; front bilobed, with shallow to well-defined median cleft; anterolateral margins arcuate, minutely granular, entire (small tubercle in some individuals). Median lobe of posterior margin of epistome (Fig. 24 A) broad, rectangular, with deep median fissure, semicircular lateral margins. Eye peduncle (Fig. 24 A) filling orbit, short, immobile; cornea reduced, pigmented. Third maxillipeds (Fig. 31 A, B) fill buccal cavern when closed; merus subquadrate, outer margin nearly straight, anteriorly flattened, anteroexternal angle rounded; ischium slightly elongated, slightly longer than merus. Chelipeds (Figs. 10 D–H; 40E, F) subequal in length, slightly dissimilar in female, heteromorphic in males; fingers of minor chela (Fig. 40 F) flattened laterally, broad throughout most of length, shear-like, cutting margins with low, broad teeth, largest most proximal on upper cutting margin in both sexes. Ventral surface of cheliped merus with 3 long, sharp teeth (sometimes additional small teeth or large tubercles) on outer margin in both sexes (Fig. 42 G), inner margin unarmed. Inner margin of carpi with long distal tooth (Fig. 10 D–H). Ambulatory legs (Fig. 10 A, D–H) proportionally long, slender. Meri of P2, P3 with short ventral teeth (Fig. 10 A), slightly larger in males; meri of other ambulatory legs with microscopic granules, unarmed. P5 dactylus straight (e.g., Fig. 10 D), P5 merus 0.8 cl. Fused thoracic sternites 1, 2 (Fig. 52 A) transversely narrow, high; fused thoracic sternites 3, 4 (Figs. 52 A; 91A) transversely narrow. Male pleon (Figs. 52 A; 59A) with lateral margins of somite 6 slightly convex, margin of somite 3 slightly convex although fused with somites 4, 5, margin of fused somites 4, 5 nearly straight; postero-lateral regions prominently swollen; telson proportionally short. Sternopleonal cavity (Fig. 52 A) deep, press-button for pleonal holding as small, short tubercle posterior to thoracic sternal suture 4/5 near edge of sterno-pleonal cavity. Male thoracic sternite 8 distinctly short, quadrate; “supplementary plate” short, rectangular; structures tightly appressed with most of penis concealed (e.g., Fig. 59 A, B). G1 (Fig. 71 A–D, F–L) stout, distal half cylindrical except for tapering tip, distal surface covered with short spinules. G2 (Fig. 71 E, M) longer than G1, distal segment slender, evenly proportioned, nearly straight, almost as long as basal segment. Somites of female pleon (Fig. 87 A) with convex lateral margins; telson proportionally short, narrow. Sterno-pleonal cavity of female (Fig. 91 A) deep, vulvae widely separated on outer margins of cavity close to suture 5/6.
Remarks. Alcock described the species based on a single female without chelipeds obtained from the Andaman Sea. The female holotype was described as “light yellow, eyes black” (Alcock 1899: 77). The figure shows a slightly bilobed rostrum, quadrate carapace, and proportionally short legs. Material from Western Australia can be confidently assigned to Alcock’s species by having a similar carapace shape and physiognomy, bilobed front (although it varies slightly, it is never straight), and ambulatory legs that are relatively short. There are some differences between the examined specimens and Alcock’s figure (Alcock 1899: 77, pl. 4, figs. 2, 2a, 2b): the outer anterior margin of the third maxilliped merus is somewhat rounded in the figure but more subangular in all specimens examined (Fig. 10 C versus Fig. 31 A, B) but this may be because Alcock’s figure was most probably drawn in situ. There is no suture visible between the male thoracic sternites 2 and 3 shown in Alcock’s figure (Alcock 1899: pl. 4, fig. 2a), but this is almost certainly an error as all specimens we have examined (as well as allied genera) possess a suture. There is also a small, obtuse tubercle (or remains of it) on each anterolateral margin of the carapace of some individuals of both sexes (e.g., Fig. 10 D, E), which is not shown in Alcock’s figure (Alcock 1899: pl. 4, figs. 2, 2b) or indicated in his brief description, but this is easily attributed to individual variation. Tesch (1918: 233) and Serène (1964a: 242) mention in their respective keys that the merus of P2 and P3 is spinous but there is no evidence that they examined Alcock’s material, and probably followed his account (see also Alcock 1900).
A reference to Hephthopelta sp. from Fiji (Clavier et al. 1996: 20, 40) could be referable to H. lugubris.
Distribution. Indian (Andaman Sea, Western Australia) and western Pacific (Papua New Guinea, Solomon Islands, New Caledonia; questionably from Fiji) oceans. Depth: 203‒1023 m.
description: Published as part of Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), pp. 1-182 in Zootaxa 4209 (1) on pages 52-53, DOI: 10.11646/zootaxa.4209.1.1, http://zenodo.org/record/272646