Chasmocarcinus latipes Rathbun 1898
Creators: name: Ng, Peter K. L.
name: Castro, Peter
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Chasmocarcinidae
Chasmocarcinus
Chasmocarcinus latipes

description: 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.
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 22-23, DOI: 10.11646/zootaxa.4209.1.1, http://zenodo.org/record/272646