Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea) Author Ng, Peter K. L. Author Castro, Peter text Zootaxa 2016 4209 1 1 182 journal article 37321 10.11646/zootaxa.4209.1.1 2de5b7bf-3975-458a-b200-07ec69f4e013 1175-5326 272646 849BAB5C-464A-4B4A-A586-5742411EDC01 Camatopsis rubida Alcock & Anderson, 1899 ( Figs. 6 ; 23A, B; 30A; 38A‒F; 51A; 58A; 67A‒F; 86A; 90A) Camatopsis rubida Alcock & Anderson, 1899 : 13 [ type localilty: Andaman Sea].—Alcock 1899: 76, pl. 4, fig. 3, 3a‒c; 1900b: 329 [Andaman Sea].—Alcock & MacGilchrist 1905: pl. 74, fig. 3, 3a [Andaman Sea].— Zarenkov 1972 : 239 , fig. 5-4 [South China Sea].— Serène & Soh 1976 : 76 , fig. 21 [Andaman Sea].— Chen 1998 : 303 , fig. 25 [South China Sea]—Ng et al. 2008: 76 [in list] (part). Camatopsis rubida Forma A—Tesch, 1918: 235, pl. 16, fig. 3a‒d [ Indonesia ]. Camatopsis rubida — Doflein 1904 : 121 [ Indonesia ]. Not Camatopsis rubida — Yokoya 1933 : 202 [ Japan ].— Sakai 1936 : 193 , pl. 55, fig. 4; 1939: 576, pl. 68, fig. 4; 1965: 173, pl. 85, fig. 4; 1976: 552, pl. 195, fig. 4 [ Japan ].— Takeda 1973a : 13 ; 1973b: 55; 1997: 247 [ Japan ].— Fang 1991 : 352 , 355, fig. 4 [map] [ Taiwan ].— Muraoka 1998 : 47 [ Japan ].—Ng et al. 2001: 34 [in list] [ Taiwan ].— Hsueh & Huang 2002 : 113 , fig. 2A [ Taiwan ]. [= C. thula n. sp. ] Not Camatopsis rubidus [ sic ] Serène & Vadon 1981 : 118 , 119, 120, 123 [ Philippines ]. [=? C . leptomerus n. sp. ] Type material (not examined). Syntypes : 3 males , Andaman Sea , 349 m . (depository unknown, possibly in the Zoological Survey of India , Calcutta ; see Alcock 1899). Other material examined . Thailand , Andaman Sea coast . Thai Danish Expedition : 1 male (3.5 × 3.6 mm ) ( ZMUC CRU- 20540 ), stn 1031-2, 07°29’N , 98°42’E , 53 m , 20.01.1966 ; 1 female (6.0 × 6.3 mm ) (ZMUC CRU- 20538), stn 1034-3, 06°58’N, 98°47’E, 76 m , 21.01.1966 ; 1 male (4.2 × 4.5 mm ) (ZMUC CRU-20539), stn 1045- 5, 05°43’40”N, 99°42’10”E, 53 m , 26.01.1966 .—1 juvenile male (2.6 × 3.0 mm) (PMBC 2062), stn 1040, 06°28’N, 99°05’E, 36 m , B. Phasuk coll., 24.01.1966 . Western Australia . CSIRO SS10-2005 RV Southern Surveyor : 1 male (10.0 × 10.3 mm ) ( NMV J54592 ), off Ningaloo South, 22°04’00”, 113°48’40”E to 22°04’15”S ,113°48’54”E, 101–106 m , G.C. Poore coll., 10.12.2005 ; 1 male (8.3 × 8.5 mm ) (NMV J54591 ), 1 male (6.7 × 7.2 mm ) (NMV J54595 ), 21°58’13”S‒21°58’45”S to 113°47’35”E‒113°47’28”E, 324–356 m , 11.12.2005 .—1 female (6.0 × 7.0 mm) (NMV J61082 ), 17°31’44”S‒17°32’30”S to 118°50’37”E‒118°50’21”E, 403–407 m , M.F. Gormon coll., 15.06.2007 .—3 juvenile females (NMV J54593 ), Ningaloo South, 201–206 m , 22°04.46’S‒22°05.14’S to 113°47.46’E‒113°47.38’E, beam trawl, 10.12.2005 ; 1 female (9.0 × 10.7 mm ) (NMV J54596 ), Ningaloo North, 373–382 m , 21°58.13’S‒21°58.48’S to 113°47.28’E–113°47.06’E, epibenthic sled, 12.12.2005 ; 1 male (9.3 × 10.4 mm ) (NMV J54590 ), Ningaloo South, 373–382 m , 22°04.19’S22°04.51’S to 113°45.22’E—113°45.22’E, epibenthic sled, 10.12.2005 . Indonesia . Sumatra . DEUTSCH TIEFSEE EXPEDITION : 1 male (5.0 × 5.5 mm ) ( ZMB 13603), stn 203, south of Bangkam , off Sumatra , 660 m , 0 4.12.1899 . SIBOGA EXPEDITION : 1 ovigerous female (NNM-ZMA 241605a), near northeast point of Java , stn 5, 07°46.0’S , 114°30.5’E , 330 m , 07.1899; 2 males (one with carapace partially crushed) , 1 female (NNM-ZMA 241605b), south of Flores , stn 306, 08°27’S , 122°54.5’E , 247 m , 07.1899 ; 1 male (9.1 × 9.8 mm ) (NNM-ZMA 241605c), Saleh Bay , north coast of Sumbawa , stn 312, 274 m , 07.1899 ; 1 female (NNM-ZMA 241605d), west of Kei Is. , stn 254, 05°40’S , 132°26’E , 310 m , 07.1899.— Tanimbar and Kei Is. KARUBAR : 1 female (MNHN-IU-2013-9078), stn DW14, 05°18’S, 132°38’E, 245–246 m , 24.10.1991 ; 1 female (MNHN-IU-2013-9079), stn DW24, 05°32’S, 132°51’E, 243– 230 m , 26.10.1991 ; 1 female (MNHN-IU-2013-9084), stn CP63, 09°00’S, 132°58’E, 215– 214 m , 01.11.1991 ; 1 female (MNHN-IU-2013- 9080), stn DW64, 09°13’S, 132°31’E, 180– 179 m , 01.11.1991 ; 1 female (MNHN-IU-2013-9082), stn CP77, 08°57’S, 131°27’E, 352– 346 m , 03.11.1991 ; 4 males (MNHN-IU-2013-9085), stn CP78, 09°06’S, 131°24’E, 295– 284 m , 0 2.11.1991 , 1 male, 1 female (MNHN-IU-2013-9083); 3 females (MNHN-IU-2013-9081), stn CP79, 09°16’S, 131°22’E, 250– 239 m , 03.11.1991 ; 1 female (MNHN-IU-2013-9077), stn CP83, 09°23’S, 131°00’E, 285–297 m , 0 4.11.1991 . FIGURE 6. Overall dorsal view of Camatopsis rubida . A, B, Andaman Sea (after Alcock 1899a: pl. 74 fig. 3, 3a); C‒E, Andaman Sea (after Alcock 1899b: pl. 4 fig. 3, 3b, 3c); F, Andaman Sea: male 4.2 × 4.5 mm (ZMUC CRU 20539); G, Australia: female 9.0 × 10.7 mm (NMV J54596 ); H, Australia: male 8.3 × 8.5 mm (NMV J54591 ); I, Australia: female 6.0 × 7.0 mm (NMV J61082 ); J, Australia: female 10.2 × 11.5 mm (QM W 17289); K, Indonesia: male 9.1 × 9.8 mm (NNM-ZMA 241605c). Papua New Guinea . BIOPAPUA: 1 male , 2 females (MNHN-IU-2011-1419), South East Point , Gulf of Huon, stn CP3629, 06°57’S , 147°08’E , 240–269 m , 22.08.2010 ; 2 males, 6 females (MNHN-IU-2011-1404), Southeast Point , Gulf of Huon, stn CP3634, 07°29’S , 147°31’E , 279–290 m , 23.08.2010 ; 4 males, 7 females (MNHN-IU- 2011-1504), Southeast Point , Gulf of Huon, stn CP3635, 07°29’S , 147°33’E , 280–302 m , 23.08.2010 ; 1 male, 2 females (MNHN-IU-2011-3461), Open Bay , stn CP3664, 04°50’S , 151°38’E , 195–340 m , 23.09.2010 ; 1 female (MNHN-IU- 2011-2590 ), Southeast Point, Manus I., stn CP3695, 02°10’S , 147°15’E , 198 m , 29.09.2010 ; 1 male , 1 female (MNHN-IU-2011-5196), Jacquinot Bay , stn DW3771, 05°34’S , 151°33’E , 295–422 m , 16.10.2010 .— PAPUA NIUGUINI : 1 female (MNHN-IU-2013-652) , 1 male (MNHN-IU-2013-11598), W. Kranket I., stn CP3948, 05°12’S, 145°51'E, 363–388 m , 26.11.2012 ; 1 male, 1 female (MNHN-IU-2013-9016), west Kranket I., stn CP3949, 05°12’S , 145°51’E , 380–407 m , 26.11.2012 ; 2 females (MNHN-IU-2013-9021), N.Huon Gulf , W. Cape Gerhards , Solomon Sea , stn CP3999, 06°45’S , 147°14’E , 360 m , 10.12.2012 ; 1 male, 1 female (MNHN-IU- 2013-4023), 1 damaged specimen, Astrolabe Bay , stn CP4023, 05°22’S , 145°48'E , 340–385 m , 14.12.2012 ; 1 female (MNHN-IU-2013-9022), Astrolabe Bay , stn CP4028, 05°22’S , 145°47’E , 300–320 m , 14.12.2012 ; 1 female (MNHN-IU-2013-1565), North Aitape , Bismarck Sea , stn CP4053, 03°03’S , 142°19’E , 300–308 m , 20.12.2012 . Australia . CSIRO RV Soela : 1 male (QM W 15386), Queensland ; 1 male (QM W 15839), Yeppoon , northeastern Queensland , stn 9, 22°56.4’S , 154°24.7’E , 678–695 m , 18.11.1985 (QM W 17023).—RV Cidaris : 4 males, 3 females , northeastern Queensland , stn 42‒2, 17°21.77’S , 146°48.52’E , J.C. U., epibenthic sled, 300 m , 15.05.1986 ; 7 males (largest 5.1 × 5.7 mm ), 4 females (largest 5.5 × 6.1 mm ) (QM W 15387), northeastern Queensland , 287–300 m , stn 46-2, 17°52.06’S , 147°02.48’E , epibenthic sled, 16.05.1986 ; 10 males (largest 6.6 × 7.4 mm ), 6 females (largest 7.2 × 8.3 mm ) (QM W 15386), northeastern Queensland , 296–303 m , stn 42–2, 17°21.77’S , 146°48.52’E , 15.05.1986 ; 1 male (QM W 15388), northern Queensland , stn 43-2, 17°34.58’S , 146°53.21’E , J.C. U., 458–500 m , 15.05.1986 .— CSIRO FRV Southern Surveyor : 1 female (10.2 × 11.5 mm ) (QM W 17289), Gulf of Carpentaria , northern Queensland , 56 m , 14°58.9’S , 139°12.1’E , dredge, 29.11.1990 . New Caledonia . BATHUS 1: 2 males , 1 female (MNHN-IU-2013-9072), stn CP695, 20°34.6’S , 164°57.9’E , 410–430 m , 17.03.1993 ; 1 female (MNHN-IU-2013-9457), east coast, stn CP656, 21°13.17’S, 165°53.98’E, 452– 460 m , 12.03.1993 ; 2 small males, 2 small females (ZRC 2015.209), stn DW654, 21°17.11’S, 165°56.77’E, 237– 298 m , 12.03.1993 ; 1 juvenile male (MNHN-IU-2013-9463), stn DW655, 21°16.78’S, 165°56.97’E, 375 m , 12.03.1993 ; 1 male (MNHN-IU-2013-9462), stn DW673, 20°48.37’S, 165°19.31’E, 170 m , 14.03.1993 .— HALIPRO 1: 1 male, 1 female (MNHN-IU-2013-9075), stn CP851, 21°43.9’S, 166°37.4’E, 314–364 m , 19.03.1994 .—EXBODI: 3 males (MNHN-IU-2011-7978), Kouakoué Canyon, stn CP3821, 21°53’S, 166°50’E, 0 7.09.2011. Fiji . MUSORSTOM 10: 1 juvenile male , 1 juvenile female (MNHN-IU-2013-9031), stn DW1319, 17°15.6’S, 178°01.9’E, 341–347 m , 06.08.1998 ; 1 male (MNHN-IU-2013-9068), south of Viti Levu, stn CP1390, 18°18.6’S , 178°5.1’E , 234–361 m , 19.08.1998 . Diagnosis . Carapace ( Fig. 6 ) subtrapezoidal, 1.0‒1.2 wider than long; front bilobed, produced to slightly produced, with slight to deep median cleft; anterolateral margins arcuate, minutely granular, granules higher along lateral margins, without distinct lobes or teeth. Epistome ( Fig. 23 A, B) slightly depressed; semicircular median lobe with deep median fissure, semicircular lateral margins without visible fissures. Eye peduncle filling ( Fig. 23 A, B) orbit, short, slightly mobile; cornea reduced, with reduced pigmentation. Third maxillipeds ( Fig. 30 A) almost entirely fill buccal cavern when closed; merus subcircular, outer margin convex, anteroexternal angle not produced; ischium subquadrate, about same length as merus. Chelipeds ( Figs. 6 ; 38A–F) subequal in length, slightly dissimilar in females, heteromorphic in males; fingers of major chela ( Fig. 38 A, C, E) proportionally long, slightly longer than propodus; thickened propodus in large males; pollex slightly longer than dactylus, armed with sharp teeth (arched, proximal, toothless gap in large males); fingers of minor chela of both sexes ( Fig. 38 B, D, F) subcircular in cross-section, scissor-like; with sharp teeth in pollex, distal two longest overlapping dactylus when closed. Inner margin of chelipeds carpus smooth. Ventral surface of cheliped merus without teeth or large tubercles. Ambulatory legs ( Fig. 6 ) proportionally short; P5 merus 0.6 cl (male cl 8.3 mm ; NMV J54591 ). Meri with microscopic granules, unarmed; long setae along anterior, posterior margins of propodi, dactyli. P5 dactylus upcurved ( Fig. 6 ). Fused thoracic sternites 1, 2 ( Fig. 51 A), triangular, proportionally narrow, short; fused thoracic sternites 3, 4 ( Figs. 51 A; 86A; 90A) relatively broad. Sterno-pleonal cavity deep, press-button for pleonal holding as small, short tubercle just posterior to thoracic sternal suture 4/5 at edge of sterno-pleonal cavity. Male pleon ( Figs. 51 A; 58A) with somite 6 broad, lateral margins convex, of fused somites 3–5 convex; telson proportionally short. G1 ( Fig. 67 A, B, D–F) stout, distal segment gently curved, distal segment curved inwards towards sternum, with short to long spinules. G2 ( Fig. 67 C) about 3/4 G1 length, straight, slender, distal segment short, straight. Female pleon ( Fig. 86 A) with lateral margins of somites strongly convex; telson proportionally short. Sternopleonal cavity of female ( Fig. 90 A) moderately deep, vulvae far apart from each other. Remarks . This species was originally described from three males collected from the Bay of Bengal at a depth of about 380 m . The specimens from northwestern Australia are generally similar in carapace shape (relatively quadrate) with similar ambulatory leg lengths (cf. Fig. 6 A, C; Alcock 1899: pl. 4 fig. 3; Alcock & MacGilchrist 1905: pl. 74 fig. 3). We were unable to examine Alcock’s type material from the Bay of Bengal, presumably at the Zoological Survey of India , Calcutta (formerly Indian Museum). Specimens with broader carapaces and relatively longer ambulatory legs from the western Pacific populations are here described as a new species, C. leptomerus n. sp. The good series of specimens of C. rubida from the northern and western parts of Australia and Andaman Sea suggest that there is some variation in the form of the G1. The largest male specimens (in excess of 8 mm cl) have a G 1 in which the distal part is less elongated, with the spinules relatively fewer and less strong ( Fig. 67 E). Smaller males (which are adult (less than 7 mm cl) have the distal part of the G1 relatively longer, with more and stronger spinules ( Fig. 67 B). The elongation of the distal part as well as the length and density of spinules is associated with size. The specimens are sympatric. A male (6.7 × 7.2 mm , NMV J54595 ) from Western Australia has a relatively shorter G1 compared to a large male (8.3 × 8.5 mm , NMV J54591 ) from the same location. The G1s of smaller males resembles those of C. africana n. sp. ( Fig. 67 G, H) but the latter has even fewer and shorter spinules even when they are comparable in size to large C. rubida ( Fig. 67 D, E). Some degree of variation was observed in the material examined. The front can be salient (male 10.0 × 10.3 mm , NMV J54592 ) and not produced and with a slight median cleft (male 8.3 × 8.5 mm , NMV J54591 ; Fig. 6 F, J, K). We nevertheless remain unsure if all the material we now refer to Camatopsis rubida represents one species. Their depth range is very substantial, varying from 36 to 695 m . It should be noted that most of our Andaman Sea material is from relatively shallow waters (less than 80 m ), whereas that from other locations usually exceed 200 m in depth. Their carapaces and G1 structures are nevertheless very similar in form and it is difficult to separate them. The present revision clarifies the confused taxonomy of what has been called “ Camatopsis rubida ” in many publications. Because of the close superficial similarity in their general carapace shape and pereiopod structure, it is often difficult to separate the species without their diagnostic G1 structures. For this reason, old records of this species must be treated with doubt unless the specimens are re-examined. As such, the records of Rathbun (1910: 344, Gulf of Thailand ) , Serène (1964a : 268, Indonesia ; 1968: 268, in list), Huang (1994 : 593 [in list], South China Sea], Ng & Davie (2002: 378 [in list], Andaman Sea) and Jiang (2008: 770, South China Sea) remain unclear. These areas all have more than one species so the specimens must be re-examined before more can be said. The records by Zarenkov (1972: 239, fig. 5-4) and Chen (1998: 303, fig. 25-8) from the South China Sea are clearly C. rubida as defined at present as their G1 structures were figured. Doflein’s (1904: 121) specimen from western Sumatra is clearly C. rubida in its carapace form and G1 structure, and it was from deeper waters as well ( 660 m ). It is also the only other species known from that part of the world. Camatopsis minor n. sp. ( type locality Indonesia ) is also believed to occur in the Andaman Sea, where it lives in waters of less than 90 m depth (see discussion for the species). One particular problem with C. rubida merits discussion. The status of “ Camatopsis rubida ” as described and figured by Tesch (1918: 235–237, pl. 16 fig. 3) is very confusing as it involves a total of four different taxa in two genera. All specimens (from eight separate stations in Indonesia ) are small and delicate, and not surprisingly, their identities confused Tesch. It is important to discuss each of them at length here to clarify this. Tesch ultimately decided there were only two forms and commented: “The various specimens present such rather important differences one from another, that at first sight I was inclined to regard them as two distinct species; on close examination, however, I have come to the conclusion, that all the specimens belong to the same species. For the sake of convenience I shall discriminate the two forms under the names A and B, beginning with A.” ( Tesch 1918: 235 ). He referred specimens from stations 5, 254, 306 and part of 312 to his “Forma A”, and specimens from stations 114, 116, 260 and part of 312 to “Forma B”. He was undecided about the single male specimen from station 302. He regarded most of the specimens (all the males) as juveniles. We examined all but one of Tesch’s specimens from the eight stations. All are small and delicate (they appear to have been previously preserved in strong formalin and most of their pereiopods have fallen off). Tesch (1918) recorded one male and one ovigerous female from station 5, but we were only able to locate the female specimen. The male specimen may have broken up in many small pieces (the bottle has considerable debris inside). The variation Tesch observed in the setation, carapace shape, third maxillipeds, and gonopods was certainly confusing because of their size but we discovered that they actually represent four separate taxa. Indeed, the small specimens in this series do show some variation in the structure of the merus and ischium of the third maxillipeds, and more considerable variation is setation. But contrary to what Tesch presumed, most of the males, although small, are mature or possess the necessary diagnostic characters. All his clear “Forma A” specimens turn out to be C. rubida s. str. His material of “Forma B” on the other hand, contained three taxa. For example, he separated the two male specimens from station 312 to two forms, and figured their G1s (drawn in situ ) ( Tesch 1918 : pl. 16 fig. 3d, e). As it turns out, one of the males is recognised here as C. rubida s. str. ( Tesch 1918: pl. 16 fig. 3e ) whereas the other is C. leptomerus n. sp. ( Tesch 1918: pl. 16 fig. 3d ). The structures of their G1s confirm this. Although Tesch was unsure about the identity of his male specimen from station 302, the G1 structure leaves no doubt it is actually C. leptomerus n. sp. All the specimens from stations 114 and 116, which he had referred to his “Forma B” turned out to be C. minor n. sp. Station 260 is arguably the most interesting. It has one male specimen of C. minor n. sp. , but, in addition, two male specimens of Microtopsis teschi n. sp. The present findings are summarised in Table 1 . TABLE 1 . Identity of the Siboga material of “ Camatopsis rubida ” previously identified by J.J. Tesch (1918).

Station	Location	Material	Tesch’s name	Present name
5	7°46’S, 114°30.5’E, near NE point of Java, 330 m	1 male, 1 ovigerous female	Forma A	Camatopsis rubida [for female specimen; male missing]
114	Kwandang Bay, entrance, 75 m	2 males, 1 female	Forma B	Camatopsis minor n. sp.
116	W of Kwandang Bay entrance, 72 m	3 males	Forma B	Camatopsis minor n. sp.
254	5°40’S, 132°26' E, W. of Kei Is., 310 m	1 female	Forma A	Camatopsis rubida
260	NW of Kei Is., 90 m	3 males	Forma B	Camatopsis minor n. sp. and Microtopsis teschi n. sp.
302	10°27.9’S, 123°28.7’E, near Rotti, 216 m	1 male	Either Forma A or B	Camatopsis leptomerus n. sp.
306	8°27’S, 122°54.5’E, S. of Flores, 247 m	2 males	Forma A	Camatopsis rubida
312	Saleh Bay, N.coast of Sumbawa, 274 m	2 males	Formas A and B	Camatopsis rubida and Camatopsis leptomerus n. sp.

Distribution . Andaman Sea, eastern Indian and western Pacific oceans ( Indonesia to New Caledonia ; Fiji ). Depth: 36‒ 695 m .