Chasmocarcinops gelasimoides Alcock, 1900

Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), Zootaxa 4209 (1), pp. 1-182 : 46-48

publication ID

https://doi.org/ 10.11646/zootaxa.4209.1.1

publication LSID

lsid:zoobank.org:pub:849BAB5C-464A-4B4A-A586-5742411EDC01

DOI

https://doi.org/10.5281/zenodo.5617115

persistent identifier

https://treatment.plazi.org/id/F16BFB33-FF8E-FFD4-FF6A-FC29FE6DFC63

treatment provided by

Plazi

scientific name

Chasmocarcinops gelasimoides Alcock, 1900
status

 

Chasmocarcinops gelasimoides Alcock, 1900 View in CoL

( Figs. 9 View FIGURE 9 ; 23I, J; 30E, F; 40A‒D; 51F; 58F; 70; 86F; 90F)

Chasmocarcinops gelasimoides Alcock, 1900: 334 View in CoL [type localilty: India].— Alcock & McArdle 1903: pl. 62, figs. 2, 2a, 3, 3a [India].— Rathbun 1910: 340, pl. 1, fig. 10, pl. 2, fig. 12 [Gulf of Thailand].— Tesch 1918: 280.— Suvatti 1938: 58 [in list]; 1950: 161 [in list].— Schmitt et al. 1973: 130 [references].— Dai & Yang 1991: 417, fig 204 (3, 4), pl. 56, fig. 4 [Guandong, China].— Chen 1998: 301 fig. 24 [Nansha Is.].— Serène 1964a: 266, fig. 20, pl. 23, fig. C [Philippines]; 1968: 92 [in list].— Serène & Soh 1976: 22 [Andaman Sea].—Dai et al. 1986: 387 [South China Sea].— Dai & Yang 1991: 417, pl. 56, fig. 4 [South China Sea].— Huang 1994: 592 [in list].—Davie et al. 2002: 331 [Andaman Sea].—Ng & Davie 2002: 378 [in list].— Jiang 2008: 770 [in list] [South China Sea].—Ng et al. 2008: 76 [in list].—Castro et al. 2010: 51 [Singapore].— Komai et al. 2012: 149 [Singapore].

Type material (not examined). 1 male, 1 female syntypes, India, off Madras [= Chennai ], 22 m (depository unknown: probably Zoological Survey of India, Kolkata; see Alcock 1900).

Material examined. Andaman Sea. THAI-DANISH EXPEDITION: 1 male (PMBC 2061), 1 male (8.8 × 9.5 mm) (PMBC 16849), 1 male (PMBC 16840); 1 female (11.5 × 12.4 mm) (PMBC 16894), stn 1035, 06°57’N, 99°11’E, 49 m, 21.01.1966.

Vietnam. 4 males ( ZRC 1970.1.23.10–13) , 3 males ( ZRC 1970.8.4.2‒4), Nhatrang Bay , 1958.

Gulf of Thailand. NAGA EXPEDITION: 3 males, 2 females ( SIO C 4411), stn S9A 60-1049, 11°36’42’N, 102°26’00”E, 33 m, beam trawl, 10.12.1960.

Peninsular Malaysia. 1 male (8.6 × 9.0 mm) ( ZRC 1965.11.24.3), Straits of Malacca, Pisang I., 01.1934. 2 females ( ZRC 1985.1379–1380 ), Johor, off Tanjong Stapa , 11–31 m, 0 7.04.1955.

Singapore. 1 male ( ZRC 1985.1381 View Materials ), off Changi, 9 m, no date. —2 males, 3 females ( ZRC 1985.1370–1374 ), Damar Laut, mud with gorgonians, 9‒14.5 m, Singapore Regional Fisheries Research Station ( SRFRS) coll. —4 males (ZRC 1989.3672–3675), Bedok, 15 m, 27.10.1982.— 1 female (9.5 × 10.4 mm) ( ZRC 1989.3676–3677 ), East Coast, 28.08.1983 .— 2 males, Southern Is. ( ZRC 2000.2612 View Materials ), shell-gravel, P.K.L. Ng coll., 01.1984. —4 males, 6 females (ZRC), D. Lane coll., 1992.—1 male (ZRC 2000.1501), Southern Is., D.G.B. Chia & Z.L. Xu coll., 01.1992.—1 male, 1 female ( ZRC 2010.0029 View Materials ), Johor Shoal, P.K.L. Ng et al. coll., 18.08.1992 .—3 males, 1 male (9.5 × 10.3 mm) ( ZRC 2000.1341 View Materials ), Johor Shoal, 01°20’08.1”N, 104°02’31.1”E, mud, D. Wee et al. coll., 14.07.1993 GoogleMaps .—1 female (ZRC 1999.0624), 1 female (ZRC 2013.1412), Angler’s Bank, Tekong-Changi Channel, 20 m, L.W. Loh coll., 01°23.628’N, 104°01’242”E, 05.08.1997; 1 male (ZRC 2013.1422), Changi/Tekong channel, Angler's Bank, 01°23.092’N, 104°01.558”E, 12 m, dredge.—1 male (8.0 × 8.3 mm) (ZRC 2009.0234), Marina East, 01°16.815’N, 103°52'645’E, T.M. Sin & A.C. Lee coll., 19.02.2009.— 1 female (9.3 × 10.6 mm) ( ZRC 2013.1411 View Materials ), Royal Singapore Yacht Club, beam trawl, 28.02.2012 .—1 female (ZRC 2013.1412), Tekong-Changi Channel, 01°23.628’N, 104°01.242”E, dredge, L.W. Loh coll., 0 5.08.1987.

Indonesia. 1 male, 1 female ( ZRC 1970.3.13.16), unknown location, R. Serène coll.—CORINDON 2 : 3 males, 5 females (MNHN-IU-2013-9048), Makassar Strait , stn CH 203, 01°08.6’S, 117°07.5’E, 25 m, 30.10.1980 GoogleMaps ; 1 female (MNHN-IU-2013-9049), stn CH 205, 01°07.8’S, 117°18.7’E, 49 m, 30.10.1980 GoogleMaps .

Diagnosis. As for genus.

Remarks. There are some slight differences between the specimens on hand from the western Pacific and Andaman Sea, including Alcock’s figures based on material from the Bay of Bengal ( Alcock & McArdle 1903: pl. 62, figs. 2, 2a, 3, 3a): relatively larger orbits and more quadrate carapace in the western Pacific specimens. Comparison with material from the Andaman Sea showed that these differences (as well as in the granulation of the carapace and the length and general shape of the G1) are not substantial and fall within the range of individual variation. The form of the major male chela also varies, with smaller specimens ( Fig. 40 View FIGURE 40 A) having less gaping fingers, strongly gaping in larger specimens ( Figs. 9 View FIGURE 9 B; 40C). It is therefore best to recognise only one species for the time being.

Rathbun (1910: 340), who treated Chasmocarcinops gelasmoides as a pinnotherid, reported on many specimens from the Gulf of Thailand, mostly from shallow, soft substrates, but she recorded one male specimen that was supposedly found from inside a living scallop Amussium pleuronectes , and she provided a photograph of the crab inside the scallop ( Rathbun 1910: pl. 1, fig. 10). This was listed by Schmitt et al. (1973: 130) in his review of pinnotherids. Serène & Soh (1976: 22) commented:

“ Rathbun (1910), recording 50 specimens from the Gulf of Thailand, mentioned only one of them as having been “in shell of living Amussium pleuronectes ". The crab gelasimoides and the mollusk pleuronectes inhabit the same grounds and are frequently mixed together in the trawl catches of the fishermen. The senior author has observed during the years several hundred specimens, but has never come across a gelasimoides in a shell of living A. pleuronectes and considers that Rathbun's observation must be attributed to chance circumstances. Rathbun did not make her observation in the field, but on preserved material collected by Mortensen several years previously. We believe that the crab and mollusk observed by Rathbun were put alive in the same basket, after being caught; the mollusk having relaxed its muscle, as is usual, the crab penetrated the shell to eat the flesh. At the fixation time, the mollusk closed its shell and kept the crab inside. Our remark on the ethology of the species provides a new reason for removing Chasmocarcinops from the Pinnotheridae .”

Serène (1964a) had earlier transferred the species to the Chasmocarcinidae (as Chasmocarcininae ). We agree with Serène & Soh (1976). All the Singapore specimens were from dredge and grab samples from soft substrates, and all the crabs were free-living. They apparently live buried in the soft mud.

Distribution. Indian (western India, Andaman Sea) and western Pacific (South China Sea to Indonesia) oceans. Depth: 9‒ 49 m.

ZRC

Zoological Reference Collection, National University of Singapore

SIO

Scripps Institution of Oceanography

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Chasmocarcinidae

Genus

Chasmocarcinops

Loc

Chasmocarcinops gelasimoides Alcock, 1900

Ng, Peter K. L. & Castro, Peter 2016
2016
Loc

Chasmocarcinops gelasimoides

Komai 2012: 149
Jiang 2008: 770
Chen 1998: 301
Huang 1994: 592
Dai 1991: 417
Dai 1991: 417
Serene 1976: 22
Schmitt 1973: 130
Serene 1964: 266
Suvatti 1938: 58
Tesch 1918: 280
Rathbun 1910: 340
Alcock 1900: 334
1900
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