Pachygrapsus transversus ( Gibbes, 1850 )

Poupin, Joseph, Davie, Peter J. F. & Cexus, Jean-Christophe, 2005, A revision of the genus Pachygrapsus Randall, 1840 (Crustacea: Decapoda: Brachyura, Grapsidae), with special reference to the Southwest Pacific species, Zootaxa 1015 (1), pp. 1-66 : 44-50

Pachygrapsus transversus ( Gibbes, 1850) ( Figures 13a–e , 14l , 15l , 16 )

Grapsus transversus Gibbes, 1850: 181 [type locality: Key West , Florida]

Goniograpsus innotatus Dana, 1851: 249 ; Dana, 1852: 345 (uncertain, probably South American coast)

Leptograpsus rugulosus H. Milne Edwards, 1853: 172 ( Brazil)

Metopograpsus dubius de Saussure, 1858: 445 [29], pl. 2, fig. 16 (St. Thomas, Virgin Is.)

Metopograpsus miniatus de Saussure, 1858: 444 [28], pl. 2, fig. 17 (St. Thomas, Virgin Is.)

Pachygrapsus innotatus — Stimpson, 1858: 48 [102] (Madeira); 1907: 116 (Madeira).

Grapsus declivifrons Heller, 1862: 521 ( Brazil) .

Pachygrapsus intermedius Heller, 1865: 44 ( Brazil) .

Pachygrapsus socius Stimpson, 1871: 114 ( Perú, Panamá, San Salvador, Manzanillo, Cabo San Lucas; see remarks).

Pachygrapsus transversus — Ortmann, 1894: 709 ( Brazil). — Rathbun, 1918: 244 (Cape Cod, Massachusetts; South Carolina; Bahamas; Florida; Texas; México; Cuba; Jamaica; Puerto Rico; St. Thomas; Trinidad; Curaçao; Brazil; Bermuda; Cape Verde Is.; Lower California; Mexico; Costa Rica; Panamá; Galápagos; Perú; part, see remarks, not specimens from Sydney and Easter I., p. 248, which are P. laevimanus ); 1921: 444, pl. 40, fig. 2­3 ( Congo); 1933: 88 ( Puerto Rico). — Tesch, 1918: 76 (Key). — Bouvier, 1940: 290 (Mediterranean). — Garth, 1946: 507, pl. 87 fig. 2 (Galápagos; differences with P. crassipes ); 1992: 4 (Revillagigedo Is.). — Capart, 1951: 186, fig. 73, pl. 3, fig. 20 (West Africa). — Monod, 1956: 415, fig. 568, 570, 572, 573 (West Africa). — Holthuis & Gottlieb, 1958: 100 (Mediterranean coast of Israel). —Zariquiez Álvarez, 1968: 425, fig. 140c, 141a ( Spain). — Chace & Hobbs, 1969: 169 (West Indies; references, distribution). — Christiansen, 1969: 92, fig. 38 ( Denmark). — Manning & Holthuis, 1981: 234 ( Nigeria, Canary Is., Morocco, Senegal, Liberia, Cameroon; synonymy, references, distribution). — Williams, 1984: 459 (from “Cape Lookout, N.C. to Montevideo, Uruguay ”; references, distribution). — Falciai & Minervini, 1992: 234. — González Pérez, 1995: 223, photo 165 (Canary Is.). — Hendrickx, 1995: 140 (references, east Pacific distribution; from California (unknown locality), USA, and Cedros I., west coast of Baja California, Mexico, south to San Lorenzo I., Perú, Revillagigedo, and Galápagos Is.). — Melo, 1996: 454 ( Brazil); 1998: 499 ( Brazil). — Cuesta & Schubart, 1998: 1499 (Pacific and Atlantic coasts of Panamá, Florida, Jamaica, Antigua, Puerto Rico, Grenada, Curaçao, Spain; morphometry and DNA sequences). —Flores & Negreiros­Fransozo, 1999: 1051 ( Brazil; secondary sexual characters and allometry). —d’Udekem d’Acoz, 1999: 256 (references, distribution, ecology). —Hickman & Zimmerman, 2000: 126, photograph (Galápagos).

Type material Type not extant, according to Rathbun (1918: 244).

Material examined

Mediterranean Sea. Egypt: Port Said, coll. H. C. Kellers, July 1922, 1 M 21.6 x 26.3 mm, 1 F 15.1 x 18.9 mm ( USNM 57443 ) .

East Atlantic. Senegal: Dakar, littoral zone, coll. D. E. Harvey, 2 August 1966, 3 M 4.7 x 6.6–10.8 x 14.2 mm, 3 ov. F 9.2 x 12.2–10.9 x 14.1 mm, 3 F 5.5 x 7.6–8.3 x 10.8 mm, 1 juv. ( USNM 125805 ) .

West Atlantic. Florida: Tortugas, coll. W. L. Schmitt, July 1930, 1 M 11.2 x 14.4 mm ( USNM 71091 ) . — French Guiana, coll. F. Geay 1906, 1 M 17.5 x 22.5 mm ( MNHN B16013; plus 3 other specimens not examined) . — Brazil, stony beach south of hotel, Villa Bella , São Sebastiao I ., coll. W. L. Schmitt, 21 September 1925, 1 M 8.4 x 10.5, 1 F 8.3 x 11.4 mm ( USNM 70955 ) . Abrolhos Is., coll. RV Albatross, 27 December 1887, 3 M 6.0 x 8.1–15.0–19.5, 1 F 11.7 x 15.5 mm ( USNM 22095 ) .

East Pacific. Costa Rica: Puntarenas, coll. J. F. Tristan, February 1905, 1 F 9.0 x 12.6 mm ( USNM 32363 ) . Perú: Praita, first point of rocks N. of railway station, coll. W. L. Schmitt, 6 October 1926, 4 M 12.2 x 15.2–14.0 x 17.5 mm, 2 F 8.8 x 11.5, 12.0– 15.5 mm, 1 ov. F 9.7 x 12.7 mm, 2 juv. ( USNM 70963 ) .

Clipperton Atoll. Beach, Jean­Louis Etienne Expedition to Clipperton, stn 11, coll. L. Albenga, J. M. Bouchard, 18 January 2005, 1 M 10.0 x 12.0 mm, 2 F 6.5 x 8.0 mm, 8.5 x 11 mm ( MNHN B29857) .

Diagnosis

Carapace weakly convex, coarsely striated on gastric, hepatic and branchial regions; striae glabrous or only with short setae; cardiac, intestinal regions with shorter striae; lateral margins convergent posteriorly (more pronounced on the smallest specimens), with tooth behind exorbital angle ( Fig. 13a ). Front 0.5 times (to 0.6 on larger specimens) exorbital width; anterior margin sinuous ( Fig. 13b ). Infraorbital margin denticulated over entire length; with deep outer notch ( Fig. 14l ).

Outer face of palm smooth, regularly convex; with marked longitudinal stria running near lower margin from tip of finger to near carpal articulation; upper margin of palm smooth or with faint carina and few oblique lines on inner face in larger specimens; cutting edges of fingers narrowly gaping with large triangular teeth; tip of fingers corneous, spoon­like, glabrous ( Fig. 13c ).

Ambulatory legs with brush of setae on P2 propodi that tends to disappear in larger males (see remarks); lower margin of P5 merus smooth or slightly incised by oblique striae of outer face; submedian tubercle usually absent, sometimes present on smallest specimens (6 x 8 mm); distoventral angle with 3–4 spines ( Fig. 13d ).

Abdominal tergites smooth. Sixth somite of male abdomen subrectangular, not forming a triangle with telson ( Fig. 13e ). G1 with elongated, petal­like tip ( Fig. 15l ).

Colour (from photographs): carapace cream to light brown with striae dark brown; cardiac and intestinal regions with a pattern of dark brown patches, symmetrical to longitudinal axis. Chelipeds dark brown to pink with paler areas on articulations and at tip of fingers. Ambulatory legs with dark brown patches on meri, carpi, and propodi, more or less arranged in bands on propodi; dactyli dark brown.

Measurements: large size; cw greater than 20 mm common; carapace of specimens examined ranging from 4.7 x 6.6–21.6 x 26.3 mm, smallest ovigerous female 9.2 x 12.2 mm.

Distribution

East Pacific. From Lower California to Perú, including the oceanic island groups of Revillagigedo, Clipperton, and the Galápagos. West Atlantic. From Cap Cod to Montevideo, including the Caribbean and Bermuda. East Atlantic. From South Portugal to Namibia, including Madeira, Canary Is., and Cape Verde Is. Mediterranean. From Alboran Sea to the Levant basin. There is one record from Denmark. According to Christiansen (1969), “in Copenhagen about 20 living specimens were found on a ship coming from the Bermudas.”

Pachygrapsus transversus is a warm­water species but with a few occasional records at high latitudes ( Fig. 16 ): Denmark to Namibia (see d’Udekem d’Acoz, 1999: 256); Cap Cod ( Rathbun, 1914) to Montevideo (William, 1984). Williams (1984: 459) indicates that this species “has been carried to higher latitudes than it normally inhabits by transport on ships’ bottoms, and … the range may have been greatly extended by commerce in modern times”.

Habitat

Intertidal on rocky shores; also recorded on sandy shores and mangroves (see d’Udekem d’Acoz, 1999: 256).

Remarks

Some characters used to identify this species vary according to size and/or sex. The lateral margin of the carapace is only weakly convergent posteriorly in large specimens, but more strongly convergent in small specimens. The striae on the cardiac and intestinal regions also tend to disappear on the smallest specimens. The front is 0.6 times the exorbital width on larger specimens but 0.5 on smaller crabs. The upper margin of the palm has a faint carina and oblique lines that tend to disappear on larger specimens. The brush of setae on P2 propodi is noticeable on small specimens and females but absent on large males. The lower margin of the P5 merus has a submedian tubercle only in small specimens.

Pachygrapsus transversus is morphologically close to P. laevimanus , and has been often confused with the former. The differences between the two are discussed under P. laevimanus .

Cuesta & Schubart (1998) studied the morphological and molecular variation of P. transversus from east, west Atlantic, and east Pacific populations. Their results suggest sufficient differentiation among these three populations that taxonomic separation can be considered. C. Schubart (pers. comm.) has indicated that a taxonomic revision is currently in progress, with the reinstatement of P.socius Stimpson, 1871 from the east Pacific, based on colour pattern, larval and adult morphometry, and DNA analysis.

Figures

FIGURE 13. —Pachygrapsus transversus (Gibbes, 1850). Male 17 x 22.5 mm, French Guiana (MNHN B16013): a) dorsal view; b) front; c) left chela outer face, d) right P5, e) male abdomen.

FIGURE 14. —Infra–orbital margin: a) Pachygrapsus fakaravensis Rathbun (1907), ov. female 15.0 x 16.5 mm, Taiaro, French Polynesia (MNHN B25782); b) Pachygrapsus laevimanus Stimpson, 1858, neotype male 18.0 x 21.7 mm, Sydney, Australia (AM P7478); c) Pachygrapsus minutus A. Milne­Edwards, 1873, male 5.2 x 7.0 mm, Moruroa, French Polynesia (MNHN B29273); d) Pachygrapsus planifrons de Man, 1888, male 7.0 x 9.0 mm, Rangiroa, French Polynesia (UF 1490); e) Pachygrapsus plicatus (H. Milne Edwards, 1837), male 12.1 x 15.3 mm, Taiaro, French Polynesia (MNHN B29279); f) Pachygrapsus corrugatus (von Martens, 1872) ov. female 13.6 x 15.2 mm, Virgin Is. (USNM 72340); g) Pachygrapsus crassipes Randall, 1840, male 31.9 x 36.6 mm, Sagami Bay, Japan (NSMT Cr7516); h) Pachygrapsus gracilis (de Saussure, 1858), ov. female 8.5 x 11 mm, Angola (MNHN B12903); i) Pachygrapsus loveridgei Chace, 1966, male 8.1 x 10 mm, St. Helena I. (MNHN B17836); j) Pachygrapsus marmoratus (Fabricius, 1787), female 12.7 x 14.3 mm, Préfailles, France (MNHN B22654); k) Pachygrapsus maurus (Lucas, 1846), female 12.7 x 14.3 mm, Banyuls, France (MNHN B12933); l) Pachygrapsus transversus (Gibbes, 1850), male 17.0 x 22.5 mm, French Guiana (MNHN B16013). Scale bar 1 mm.

FIGURE 15. —Male gonopods: a) Pachygrapsus fakaravensis Rathbun (1907), holotype 18.0 x 19.4 mm, Fakarava, French Polynesia (USNM 32844), right G1, abdominal face (left) and detail of terminal portion, sternal face (right); b) Pachygrapsus laevimanus Stimpson, 1858, neotype 18.0 x 21.7 mm, Sydney, Australia (AM P7478), left G1, abdominal (left) and sternal face (right), setae omitted; c) Pachygrapsus minutus A. Milne­Edwards, 1873, cl 8.2 mm, Caroline Is., lateral (left) and abdominal face (right), setae omitted; d) Pachygrapsus planifrons de Man, 1888, 9.5 x 11.8 mm, Hawaiian Is. (USNM 29350), right G1, abdominal (left) and sternal face (right); e) Pachygrapsus plicatus (H. Milne Edwards, 1837), cl 11.7 mm, Hawaiian Is., lateral (left) and abdominal face (right); f) Pachygrapsus corrugatus (von Martens, 1872), cl 8.5 mm, Ascension I., left G1 abdominal face (left) and detail of terminal portion, setae omitted (right); g) Pachygrapsus crassipes Randall, 1840, cl 35.6 mm, California, lateral (left) and abdominal face (right) setae omitted; h) Pachygrapsus gracilis (de Saussure, 1858), cl 8.7 mm, Virgin Is., lateral (left) and abdominal face (right), setae omitted; i) Pachygrapsus loveridgei Chace, 1966, holotype 10.3 x 13.1 mm, St. Helena I. (USNM 112457), left G1, abdominal (left) and sternal face (right); j) Pachygrapsus marmoratus (Fabricius, 1787), cl 30.5 mm, Gibraltar, lateral (left) and abdominal face (right), setae omitted; k) Pachygrapsus maurus (Lucas, 1846), cl 8.5 mm, Canary Is., lateral (left) and abdominal face (right) setae omitted; l) Pachygrapsus transversus (Gibbes, 1850), cl 11.1 mm, Key West, Florida, lateral (left) and abdominal face (right), setae omitted. (c, e, g–l, from Chace, 1966, fig. 10–11; f, from Manning & Chace, 1990, fig. 43). Approximate magnification x 6 (x 12 for detail of terminal portion).

FIGURE 16. —Geographic distribution of: a) Pachygrapsus crassipes Randall, 1840 (Stars); b) Pachygrapsus transversus (Gibbes, 1850) (full dots); and c) P. laevimanus Stimpson, 1858 (empty dots). a–b, mostly from literature; c) from collections examined during this study. Occurrence of P. laevimanus at Easter I. uncertain (?) and must be confirmed by examination of G1 (see text).