Chasmocarcinus latipes Rathbun, 1898

Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), Zootaxa 4209 (1), pp. 1-182 : 22-23

Chasmocarcinus latipes Rathbun, 1898

( Figs. 1 E; 4A‒E; 5D; 22A, B; 29C‒E; 36E‒H; 50A, C, D; 57A; 65A‒D; 84E, F; 89E, F)

Chasmocarcinus latipes Rathbun, 1898b: 602 , pl. 43, fig. 5 [type localilty: Baja California, Mexico]; 1918: 5 [in key], 57, figs. 25, 26 [Baja California].— Crane 1937: 49, 75 [Baja California].— Garth 1948: 52 [Colombia, Ecuador]; 1961: 155 [El Salvador, Costa Rica, Panama].— Serène 1964a: 258 [in list].— Blow & Bailey 1992: 176 [in list].—Lemaitre & Álvarez León 1992: 55 [in list].— Hendrickx 1995: 139 [in list].—Ng et al. 2008: 76 [in list].—Vargas & Wehrtmann 2009: 195 [CD; in list].

Chasmocarcinus ferrugineus Glassell, 1936: 216 ; Crane 1937: 75, pl. 7 fig. 24 [Baja California].—Ng et al. 2008: 76 [in list].

Chasmocarcinus latipes — Luke, 1977: 53 [in list].

cf. Chasmocarcinus — Luke, 1977: 53 [in list].

Type material. Holotype female (12.4 × 14.4 mm) ( USNM 21592 ), Mexico, Baja California, Magdalena Bay , Albatross, stn 2833, 93 m, 2 May 1888.

Other material examined. Mexico. 1 male, broken (cl 10.0 mm) ( LACM), E. Ángel de la Guarda I. , Gulf of California, stn VSS-101, 20 m, 9.04.1959.—2 ovigerous females (14.0 × 16.0 mm, 11.8 × 14.1 mm), 1 male (13.2 × 16.4) ( MBPC 16356 ), Sebastián Vizcaíno Bay , Cedros I., 11.08.1952, J. Littlepage coll.; 2 ovigerous females (12.4 × 14.9 mm, 11.4 × 13.4 mm) , 1 male (12.2 × 13.6) (MBPC16356), 74‒81 m.—CORTES 2: 2 males (EMU- 3474-B), off Santa Inez Bay , Gulf of California , Baja California, El Puma , stn 49-B, 19.03.1995.— 1 male (9.9 × 13.5 mm) ( SIO C 320) , Bahía Santa Inés , Baja California, stn MV68- I-37, 26 °58’N, 110°40’W, 62 m, 41-feet otter trawl, C. Hubbs coll., T . Washington, 14.01.1968; 3 males (largest 8.3 × 11.0 mm) , 2 females (largest 9.4 × 11.6 mm) ( SIO C 319), Bahía de La Paz , Baja California, stn MV68- I-29, 24 °25’N, 110°25’W, 82‒119 m, 40-foot otter trawl, C. Hubbs coll., T . Washington, 12.01.1968.—TEMPLETON CROCKER’S EXPEDITION : 1 female (holotype of Chasmocarcinus ferrugineus Glassell, 1936 ) (9.2 × 13.0 mm) (AMNH 16262), 1 female (paratype of Chasmocarcinus ferrugineus Glassell, 1936 ) (7.5 × 10.5 mm) ( AMNH 16263 ), 5 miles southeast of Punta Arena , Gulf of California , Baja California, stn 136, 23°29’N, 109°25'W, 81 m, dredge 21, 4-foot Blake dredge, Zaca, W. Beebe coll, 30.04.1936.— ALLAN HANCOCK EXPEDITION (1937) : 1 female ( MBPC 16358 ), Espíritu Santo I., Gulf of California, Velero III, stn 632-37 , 44 m.—BACANYON CRUISE: 1 male (7.2 × 9.7 mm) ( SIO C 1298), Cabo San Lucas , Baja California, stn 63, 22°52.9’N, 109°53.5’W, 110‒128 m, 15.02.1962 .

Costa Rica. 1 female (6.6 × 8.5 mm) ( SIO C 1189), Golfo de Nicoya, stn MV68- I-96, 09 °27.3’N ‒09°27.7’N to 84°30.1’W‒84°31.3’W, 31 m, 25-foot otter trawl, Agassiz, C. Hubbs & S. Luke coll., 22 April 1973.

Panama. ALLAN HANCOCK EXPEDITION (1934): 1 female ( LACM), Bahía Honda, Velero III, stn 213-39, 55 m, 10.02.1934 .— EASTERN PACIFIC ZACA EXPEDITION: 1 female ( MBPC 16361 ), Gulf of Chiriquí, stn 221, D-4, 64 m, 13.03.1938 .

Colombia. ALLAN HANCOCK EXPEDITION (1938): 1 ovigerous female ( MBPC 16363 ), Puerto Utría, Velero III, stn 856-38, 37‒ 55 m, 25.02.1938.

Ecuador. ASKOY EXPEDITION: 4 males (10.5 × 14.5 mm, 10.5 × 14.3 mm, 8.9 × 11.5 mm, 7.7 × 9.8 mm) , 1 female (10.1 × 13.9 mm) (AMNH 1941-10668), stn 87, sample 344, 0 0°55’N, 80°08’W, 65‒98 m, 17.04.1941; 1 male (MBPC16360), stn 87, 0 1°07’N, 79°53’W, 36‒55 m, 17.04.1941.— ALLAN HANCOCK EXPEDITION (1934): 1 female ( MBPC 16368 ), Isla La Plata, Velero III, stn 231-34, 13‒ 18 m, 10.02.1934 .

Peru. 2 females ( MBPC 16359 ), off Talara, 94 m, shell and sand, E. M. del Solar coll., 1.09.1970.

Diagnosis. Carapace ( Fig. 4 A‒E) granular, with granular ridge along anterolateral margins, front nearly straight. Epistome ( Fig. 22 A, B) with subtriangular median lobe with median fissure, lateral margins slightly curved. Orbits long, eye peduncles proportionally long ( Fig. 22 A, B). Antennular articles relatively short ( Fig. 22 A, B). Third maxilliped ( Fig. 29 C‒E) merus broadly ovate; ischium quadrate, about as long as merus.

Pterygostomial region gently convex, not bulging, not visible from dorsal view ( Fig. 5 D). Fingers of major chela of males ( Fig. 36 G) proportionally long, slightly longer than propodus in dorsal view; with small, short teeth. Fingers of minor chela of both sexes ( Fig. 36 F, H) scissor-like; with small, sharp teeth. Inner margin of cheliped carpus ( Fig. 4 A‒E; Rathbun 1918: fig. 25) with short, blunt tooth. Ambulatory legs ( Fig. 4 A‒E) proportionally short, wide, stout; subdistal spur present on P5 dactylus. Fused thoracic sternites 1, 2 ( Fig. 50 A) broadly triangular, proportionally narrow, long. Male pleon ( Figs. 50 A, C, D, 57A) with low to high tubercle on distomedial margin of somite 6, telson proportionally long, narrow. G1 ( Fig. 65 A‒C) stout, spinules along distal third. G2 ( Fig. 65 D) straight, slender, distal segment long, slightly curved; about 3/4 as long as G1. Female pleon ( Fig. 84 E, F) with lateral margins of somites strongly convex; telson proportionally short. Sterno-pleonal cavity of female ( Fig. 89 E, F) moderately shallow, vulvae relatively close together.

Remarks. Very characteristic and unique among congeners are the ambulatory legs of C. latipes , being proportionally short and having conspicuously wide articles ( Fig. 4 A‒E) as well as a subdistal spur on the P5. The pterygostomial region is gently convex but bulging in all congeners, and as such, not clearly visible from dorsal view ( Fig. 5 D). The lateral margins of the posterior margin of the epistome are slightly curved ( Fig. 22 A, B) but straight in Atlantic congeners.

The male pleonite 6 of all Chasmocarcinus species often has the distal median part slightly convex. In some species, it is slightly more prominent and appears as a low subrectangular or obtuse tubercle (e.g., C. typicus : Fig. 56 A). The tubercle of C. latipes , however, is very pronounced and is clearly visible as a sharp tubercle ( Fig. 57 A). There is variation; it is lower in some specimens ( Fig. 50 C) or high ( Fig. 50 D); but is always distinct.

Glassell (1936) described Chasmocarcinus ferrugineus on the basis of two females (one holotype) and male from Mexico; but no figures were provided. Garth (1948) was the first to suggest that Chasmocarcinus ferrugineus Glassell, 1936 , was a junior subjective synonym of C. latipes , although he did not provide any figures as well. We have examined the holotype female (AMNH 16262) and the supposed paratype male (AMNH 16263) and agree with him that the two names are synonyms. The supposed paratype “male” specimen, however, is actually a young female.

Distribution. Tropical Eastern Pacific, from northern Gulf of California to northern Peru. Depth: 13‒ 128 m.

Figures

FIGURE 1. A, Acidopsidae: Typhlocarcinodes integrifrons (Miers, 1881), Senegal: lectotype male 6.9 × 8.5 mm (NHM 81.24 a); B, Acidopsidae: Raoulia limosa, Lombok, Indonesia: male 6.5 × 11.8 mm (MZB Cru 3914); C, Acidopsidae: Caecopilumnus crassipes (Tesch, 1918), Indonesia: male 10.1 × 11.8 mm (ZRC 2013.1710); D, Scalopidiidae: Scalopidia spinosipes, Singapore: male 12.2 × 16.7 mm (ZRC 2000.1604); E, Chasmocarcinidae: Chasmocarcinus latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668). Abbreviations: a 1 ‒ a 6 = pleonites 1 ‒ 6, respectively; cx 3 ‒ cx 5 = coxa of P 3 ‒ P 5, respectively; sp = “ supplementary plate ”; st 5 ‒ st 8 = thoracic sternites 5 ‒ 8, respectively; po = opening of penis; ps = start of penis.

FIGURE 4. Overall dorsal view of species of Chasmocarcinus. A, C. latipes, Mexico: holotype female 12.4 × 14.4 mm (USNM 21592); B, C. latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668); C, C. latipes, Ecuador: male 10.5 × 14.3 mm (AMNH 1941 - 10668); D, C. latipes, Mexico: female 9.2 × 13.0 mm (AMNH 16262, holotype female of Chasmocarcinus ferrugineus Glassell, 1936); E, C. latipes, Mexico: female 7.5 × 10.5 mm (AMNH 16262, paratype female of Chasmocarcinus ferrugineus Glassell, 1936); F, C. longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785); G, C. meloi, Brazil: holotype male 5.3 × 6.2 mm (after Coelho & Coelho 1998: fig. 8 a); H, C. mississippiensis, Gulf of Mexico: holotype male 8.3 × 10.4 mm (USNM 64074).

FIGURE 5. Overall dorsal view of species of Chasmocarcinus, Amboplax n. gen. and Deltopelta n. gen. A, Amboplax peresi, Brazil: male 5.1 × 6.4 mm (ZRC 2015.217); B, Amboplax peresi, Brazil: ovigerous female 4.9 × 6.2 mm (ZRC 2015.217); C, Chasmocarcinus gemmatus n. sp., Costa Rica: male 7.7 × 11.6 mm (SIO C 1205); D, Chasmocarcinus latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668); E, Deltopelta obliquus, A, Bahamas: holotype male 5.2 × 5.1 mm (USNM 20509); F, Deltopelta obliquus, Belize: female 10.7 × 13.0 mm (PMNH, holotype of Hephthopelta superba); G, Deltopelta obliquus, Belize: female 10.7 × 13.0 mm (PMNH, holotype of Hephthopelta superba, after Boone 1927: fig. 5).

FIGURE 22. Frontal view of cephalothorax of species of Chasmocarcinus, Amboplax n. gen. and Deltopelta n. gen. A, Chasmocarcinus latipes, Mexico: holotype female 12.4 × 14.4 mm (USNM 21592); B, Chasmocarcinus latipes, Mexico: female 9.2 × 13.0 mm (AMNH 16262, holotype female of Chasmocarcinus ferrugineus Glassell, 1936); C, Chasmocarcinus longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785); D, Chasmocarcinus meloi, Brazil: holotype female 5.3 × 6.2 mm (after Coelho & Coelho 1998: fig. 8 b); E, Chasmocarcinus mississippiensis, Gulf of Mexico: holotype male 8.3 × 10.4 mm (USNM 64074); F, G, Amboplax peresi, Brazil: male 5.1 × 6.4 mm (ZRC 2015. 217); H, Deltopelta obliquus, Bahamas: holotype male 5.2 × 5.1 mm (USNM 20509).

FIGURE 29. Third maxilliped of species of Chasmocarcinus and Deltopelta n. gen. A, Chasmocarcinus gemmatus n. sp., Costa Rica: male 7.7 × 11.6 mm (SIO C 1205); B, C. hirsutipes, Brazil: holotype male 6.6 × 7.0 mm (after Coelho & Coelho 1998: fig. 6 c); C, Chasmocarcinus latipes, Mexico: holotype female 12.4 × 14.4 mm (USNM 21592); D, Chasmocarcinus latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668); E, Chasmocarcinus latipes, Mexico: female 9.2 × 13.0 mm (AMNH 16262, holotype female of Chasmocarcinus ferrugineus Glassell, 1936); F, Chasmocarcinus longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785); G, C. meloi, Brazil: holotype male 5.3 × 6.2 mm (after Coelho & Coelho 1998: fig. 8 c); H, Chasmocarcinus mississippiensis, Gulf of Mexico: male 7.2 × 8.8 mm (USNM 101082); I, Deltopelta obliquus, Bahamas: holotype male 5.2 × 5.1 mm (USNM 20509).

FIGURE 36. Chelae of species of Chasmocarcinus. A, B, C. gemmatus n. sp., Costa Rica: male 7.7 × 11.6 mm (SIO C 1205); C, D, C. hirsutipes, Brazil: holotype male 6.6 × 7.0 mm (after Coelho & Coelho 1998: fig. 6 e, f); E, C. latipes, Mexico: holotype female 12.4 × 14.4 mm (USNM 21592); F, C. latipes, Mexico: female 9.2 × 13.0 mm (AMNH 16262, holotype female of Chasmocarcinus ferrugineus Glassell, 1936); G, H, C. latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668); I, J, C. longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785).

FIGURE 50. Anterior thoracic sternum and male pleon of species of Chasmocarcinus, Amboplax n. gen. and Deltopelta n. gen. A, C, Chasmocarcinus latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668); B, Chasmocarcinus longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785); D, Chasmocarcinus latipes, D, Mexico: male 8.3 × 11.0 mm (SIO C 319); E, Chasmocarcinus meloi, Brazil: holotype male 5.3 × 6.2 mm (after Coelho & Coelho 1998: fig. 9 d); F, Chasmocarcinus mississippiensis, Gulf of Mexico: male 7.2 × 8.8 mm (USNM 101082); G, Amboplax peresi, Brazil: male 5.1 × 6.4 mm (ZRC 2015. 217); H, Deltopelta obliquus, Bahamas: holotype male 5.2 × 5.1 mm (USNM 20509).

FIGURE 56. Thoracic sternites 7 and 8 and male pleon of species of Chasmocarcinus. A, C. typicus, Trinidad: holotype male 7.8 × 8.7 mm (USNM 6901); B, C. arcuatus, Brazil: male 5.7 × 7.7 mm (ZRC 2015.221); C, C. arcuatus, Brazil: male 3.7 × 5.1 mm (ZRC 2015.220); D, C. chacei, Gulf of Mexico: male 6.6 × 8.0 mm (USNM 61489); E, C. cylindricus, Jamaica: male 3.6 × 4.9 mm (USNM 42942); F, C. gemmatus n. sp., Costa Rica: male 7.7 × 11.6 mm (SIO C 1205).

FIGURE 57. Thoracic sternites 7 and 8 and male pleon of species of Chasmocarcinus, Amboplax n. gen. and Deltopelta n. gen. A, Chasmocarcinus latipes, Ecuador: male 10.5 × 14.5 mm (AMNH 1941 - 10668); B, Chasmocarcinus longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785); C, Chasmocarcinus mississippiensis, Gulf of Mexico: holotype male 8.3 × 10.4 mm (USNM 64074); D, Amboplax peresi, Brazil: male 5.1 × 6.4 mm (ZRC 2015. 217); E, Deltopelta obliquus, Bahamas: holotype male 5.2 × 5.1 mm (USNM 20509).

FIGURE 65. Gonopods of species of Chasmocarcinus. A ‒ D, C. latipes, Ecuador: male 10.5 × 14.3 mm (AMNH 1941 - 10668); E ‒ H, C. longipes, Colombia: paratype male 5.5 × 6.4 mm (USNM 78785); I, C. hirsutipes, Brazil: holotype male 6.6 × 7.0 mm (after Coelho & Coelho 1998: fig. 7 d); J, C. meloi, Brazil: holotype male 5.3 × 6.2 mm (after Coelho & Coelho 1998: fig. 9 e). A, E, ventral view of left G 1; B, ventral view of distal part of left G 1; C, F, dorsal view of distal part of left G 1; G, ventral view of tip of left G 1; D, H, left G 2; I, J, ventral view of right G 1. Scales: A, D = 0.5 mm; E, F, H = 0.25 mm; I ‒ K = 1.0 mm; B, C, G = 0.1 mm.

FIGURE 84. Female thoracic sternum and pleon of species of Chasmocarcinus. A, C. typicus, Trinidad: paratype female 6.5 × 6.8 mm (USNM 6901); B, C. arcuatus, Brazil: female 4.4 × 6.2 mm (ZRC 2015.222); C, C. chacei, Gulf of Mexico: female 7.8 × 9.5 mm (USNM 61489); D, C. cylindricus, Puerto Rico: female 6.9 × 9.2 mm (USNM 24551); E, C. latipes, Mexico: neotype female 12.4 × 14.4 mm (USNM 21592); F, C. latipes, Mexico: female 9.2 × 13.0 mm (AMNH 16262, holotype female of Chasmocarcinus ferrugineus Glassell, 1936).

FIGURE 89. Vulvae of species of Chasmocarcinus, Amboplax n. gen. and Deltopelta n. gen. A, Chasmocarcinus typicus, Trinidad: paratype female 6.5 × 6.8 mm (USNM 6901); B, Chasmocarcinus arcuatus, Brazil: female 4.4 × 6.2 mm (ZRC 2015.222); C, Chasmocarcinus chacei, Gulf of Mexico: female 7.8 × 9.5 mm (USNM 61489); D, Chasmocarcinus cylindricus, Puerto Rico: female 6.9 × 9.2 mm (USNM 24551); E, Chasmocarcinus latipes, Mexico: holotype female 12.4 × 14.4 mm (USNM 21592); F, C. latipes, Mexico: female 9.2 × 13.0 mm (AMNH 16262, holotype female of Chasmocarcinus ferrugineus Glassell, 1936); G, Chasmocarcinus longipes, Colombia: paratype female 5.6 × 6.8 mm (USNM 78785); H, Chasmocarcinus mississippiensis, Gulf of Mexico: female 9.6 × 12.4 mm (USNM 150090); I, Amboplax peresi, Brazil: ovigerous female 4.9 × 6.2 mm (ZRC 2015. 217); J, Deltopelta obliquus, Belize: female 10.7 × 13.0 mm (PMNH, holotype of Hephthopelta superba).