Hephthopelta lugubris Alcock, 1899

Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), Zootaxa 4209 (1), pp. 1-182 : 52-53

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.

Figures

FIGURE 10. Overall dorsal view, frontal view and anterior thoracic sternum of species of Hephthopelta. A ‒ C, H. lugubris, Andaman Sea: female (after Alcock 1899 b: pl. 14 fig. 2, 2 a. 2 b); D, H. lugubris, Australia: male 7.9 × 8.3 mm (NMV J 61081); E, H. lugubris, Australia: ovigerous female 6.3 × 6.6 mm (NMV J 61083); F, H. lugubris, Solomon Is: male 8.3 × 9.1 mm (MNHN-IU- 2013 - 9040); G, H. lugubris, Solomon Is.: male 7.3 × 7.8 mm (MNHN-IU- 2013 - 9037); H, H. lugubris, Fiji: male 6.3 × 6.5 mm (MNHN-IU- 2013 - 9028); I, H. occidentalis n. sp., Madagascar: holotype male 6.1 × 6.6 mm with sacculinid (MNHN-IU- 2010 - 1031); J, H. occidentalis n. sp., Madagascar: paratype male 4.7 × 4.9 mm (ZRC 2015.247).

FIGURE 24. Frontal view of species of Hephthopelta and Angustopelta n. gen. A, Hephthopelta lugubris, Australia: male 7.9 × 8.3 mm (NMV J 61081); B, Hephthopelta occidentalis n. sp., Madagascar: holotype male 6.1 × 6.6 mm with sacculinid (MNHN-IU- 2010 - 1031); C, Angustopelta aurita, Philippines: holotype female 18.9 × 19.1 mm (USNM 46405); D, Angustopelta aurita, Philippines: male 9.2 × 10.6 mm (ZRC 2015.251); E, Angustopelta cribrorum, Japan: holotype male 13.6 × 14.9 mm (USNM 46388); F, Angustopelta robusta n. sp., Vanuatu: holotype male 9.3 × 10.7 mm (MNHN-IU- 2010 - 5616); G, Angustopelta modesta n. sp., Solomon Islands: holotype male 13.3 × 15.1 mm (MNHU-IU- 2013 - 9038); H, Angustopelta aff. modesta n. sp., Papua New Guinea: female 9.0 × 10.2 mm (ZRC 2015.259).

FIGURE 31. Third maxilliped of species of Hephthopelta and Angustopelta n. gen. A, B, Hephthopelta lugubris, Australia: male 7.9 × 8.3 mm (NMV J 61081); C, Hephthopelta occidentalis n. sp., Madagascar: holotype male 6.1 × 6.6 mm with sacculinid (MNHN-IU- 2010 - 1031); D, Angustopelta aurita, Philippines: holotype female 18.9 × 19.1 mm (USNM 46405); E, Angustopelta aurita, Philippines: male 9.2 × 10.6 mm (ZRC 2015.250); F, Angustopelta cribrorum, Japan: holotype male 13.6 × 14.9 mm (USNM 46388); G, Angustopelta robusta n. sp., Vanuatu: holotype male 9.3 × 10.7 mm (MNHN-IU- 2010 - 5616); H, Angustopelta modesta n. sp., Solomon Islands: holotype male 13.3 × 15.1 mm (MNHU-IU- 2013 - 9038); I, Angustopelta modesta n. sp., Solomon Islands: paratype male 11.5 × 13.2 mm (MNHU-IU- 2013 - 9039).

FIGURE 40. Chelae of species of Chasmocarcinops and Hephthopelta. A, B, Chasmocarcinops gelasimoides, Andaman Sea: male 8.8 × 9.5 mm (PMBC 16849); C, D, Chasmocarcinops gelasimoides, Singapore: male 9.5 × 10.3 mm (ZRC 2000.1341); E, F, Hephthopelta lugubris, Australia: male 7.9 × 8.3 mm (NMV J 61081); G, H, Hephthopelta occidentalis n. sp., Madagascar: holotype male 6.1 × 6.6 mm, with sacculinid (MNHN-IU- 2010 - 1031).

FIGURE 42. P 4, P 5, and merus of cheliped of species of Angustopelta n. gen. A, A. robusta n. sp., Vanuatu: paratype male 12.3 × 13.3 mm (ZRC 2015.255); B, A. robusta n. sp., Vanuatu: paratype female 13.4 × 15.1 mm (MNHN-IU- 2010 - 5616); C, A. robusta n. sp., Vanuatu: paratype male 12.5 × 14.8 mm (MNHN-IU- 2013 - 9041); D, A. modesta n. sp., Solomon Islands: holotype male 13.3 × 15.1 mm (MNHU-IU- 2013 - 9038); E, A. modesta n. sp., Solomon Islands: paratype female 13.1 × 15.3 mm (ZRC 2015.258); F, A. aff. modesta n. sp., Papua New Guinea: female 9.3 × 9.9 mm (MNHN-IU- 2011 - 3307); G, Hephthopelta lugubris, Papua New Guinea: female 9.8 × 10.9 mm (MNHN-IU- 2011 - 2657), major cheliped; H, Angustopelta aurita, Philippines: female 10.9 × 12.7 mm (ZRC 2015.248), minor cheliped; I, Tenagopelta pacifica n. sp., Indonesia: male 11.0 × 12.4 mm (MNHU-IU- 2013 - 9053), minor cheliped; J, Chinommatia cavimanus, Philippines: male 9.7 × 11.5 mm (ZRC 2015.234), minor cheliped; K, Chinommatia cavimanus, Philippines: male 7.6 × 9.3 mm (ZRC 2015.231), minor cheliped; L, Notopelta mortenseni, Indonesia: holotype male 5.0 × 6.9 mm (ZMUC CRU- 7397), major cheliped; M, Statommatia apta, Philippines: males 8.5 × 10.3 mm (ZRC 2015.237), minor cheliped; N, Statommatia malagasy n. sp., Madagascar: male 8.8 × 11.0 mm (MNHN-IU- 2010 - 4370 b), minor cheliped.

FIGURE 52. Anterior thoracic sternum and male pleon of species of Hephthopelta and Angustopelta n. gen. A, Hephthopelta lugubris, Australia: male 7.9 × 8.3 mm (NMV J 61081); B, C, Hephthopelta occidentalis, Madagascar: holotype male 6.1 × 6.6 mm with sacculinid (MNHN-IU- 2010 - 1031); D, Angustopelta aurita, Philippines: male 9.2 × 10.6 mm (ZRC 2015.250); E, Angustopelta cribrorum, Japan: holotype male 13.6 × 14.9 mm (USNM 46388); F, A. cribrorum, Taiwan: male 9.9 × 11.6 mm (ZRC 2015.214); G, Angustopelta robusta n. sp., Vanuatu: holotype male 9.3 × 10.7 mm (MNHN-IU- 2010 - 5616); H, A. modesta n. sp., Solomon Islands: holotype male 13.3 × 15.1 mm (MNHU-IU- 2013 - 9038).

FIGURE 59. Thoracic sternites 7 and 8, male pleon and sterno-pleonal cavity of species of Hephthopelta and Angustopelta n. gen. A, Hephthopelta lugubris, Australia: male 7.9 × 8.3 mm (NMV J 61081); B, Hephthopelta lugubris, Solomon Is: male 8.3 × 9.1 mm (MNHN-IU- 2013 - 9040); C, Hephthopelta occidentalis n. sp., Madagascar: holotype male 6.1 × 6.6 mm with sacculinid (MNHN-IU- 2010 - 1031); D, Angustopelta aurita, Philippines: male 9.2 × 10.6 mm (ZRC 2015.250); E, Angustopelta cribrorum, Japan: holotype male 13.6 × 14.9 mm (USNM 46388); F, Angustopelta robusta n. sp., Vanuatu: holotype male 9.3 × 10.7 mm (MNHN-IU- 2010 - 5616); G, Angustopelta modesta n. sp., Solomon Islands: holotype male 13.3 × 15.1 mm (MNHU-IU- 2013 - 9038); H, Angustopelta modesta n. sp., Solomon Islands: paratype male 11.5 × 13.2 mm (MNHU- IU- 2013 - 9039); I, Angustopelta cribrorum, Taiwan: male 9.9 × 11.6 mm (ZRC 2015.214); J, Angustopelta robusta n. sp., Vanuatu: holotype male 9.3 × 10.7 mm (MNHN-IU- 2010 - 5616). Abbreviations: pb = press buttom male pleonal locking mechanism.

FIGURE 71. Gonopods of Hephthopelta lugubris. A ‒ E, Australia: male 7.9 × 8.3 mm (NMV J 61081); F ‒ I, Solomon Is: male 8.3 × 9.1 mm (MNHN-IU- 2013 - 9040); J, Solomon Is: male 7.3 × 7.8 mm (MNHN-IU- 2013 - 9037); K ‒ M, Fiji: male 6.3 × 6.5 mm (MNHN-IU- 2013 - 9028). A, B, F, J, K, ventral view of left G 1; C, H, ventral view of distal part of left G 1; D, I, dorsal view of distal part of left G 1; E, M, left G 2; G, L, dorsal view of left G 1. Scales: A, B, E, F, G, J ‒ M = 0.5 mm; C, D, H, I = 0.1 mm.

FIGURE 87. Female thoracic sternum and pleon of species of Hephthopelta, Angustopelta n. gen., Chinommatia n. gen. and Notopelta n. gen. A, Hephthopelta lugubris, Australia: ovigerous female 6.3 × 6.6 mm (NMV J 61083); B, Angustopelta aurita, Philippines: female 8.7 × 10.0 mm (ZRC 2015.253); C, Angustopelta robusta n. sp., Vanuatu: paratype female 13.4 × 15.1 mm (MNHN-IU- 2010 - 5616); D, Chinommatia cavimanus, Philippines: female 7.6 × 9.0 mm (ZRC 2015.228); E, Chinommatia bruuni, Malaysia: female 5.5 × 7.2 mm (ZRC 2013.0020); F, G, Notopelta mortenseni, Indonesia: female 5.9 × 4.1 mm (ZMUC CRU- 007768). Vulvae exposed in E, G.

FIGURE 91. Vulvae of species of Hephthopelta, Angustopelta n. gen., Chinommatia n. gen., Statommatia n. gen. and Tenagopelta n. gen. A, Hephthopelta lugubris, Australia: ovigerous female 6.3 × 6.6 mm (NMV J 61083); B, Angustopelta aurita, Philippines: female 8.7 × 10.0 mm (ZRC 2015.253); C, Angustopelta robusta n. sp., Vanuatu: paratype female 13.4 × 15.1 mm (MNHN-IU- 2010 - 5616); D, Chinommatia cavimanus, Philippines: female 7.6 × 9.0 mm (ZRC 2015.228); E, Statommatia apta, Philippines: female 8.5 × 10.6 mm (ZRC 2015.238); F, Statommatia malagasy n. sp., Madagascar: paratype female 9.4 × 8.1 mm (ZRC 2015.215); G, Tenagopelta pacifica n. sp., Philippines: female 9.2 × 10.4 mm (ZRC 2015.187); H, Tenagopelta brachyphallus n. sp., Australia: female 6.9 × 7.6 mm (NMV J 61680).