Petrolisthes armatus ( Gibbes, 1850 )

Ferreira, Luciane Augusto De Azevedo & Anker, Arthur, 2021, An annotated and illustrated checklist of the porcelain crabs of Panama (Decapoda: Anomura), Zootaxa 5045 (1), pp. 1-154 : 67-70

Petrolisthes armatus ( Gibbes, 1850)

( Figs. 36 , 37 )

Porcellana armata Gibbes 1850: 190 .

Petrolisthes armatus . — Haig 1956: 19; Haig 1957: 9; Chace 1956: 15, fig. 5A–E; Haig 1962: 178; Holthuis & Manning 1970: 242; Gore 1974: 709; Lewinsohn 1976: 67; Werding 1977: 198, fig. 18; Werding 1978a: 214; Abele & Kim 1989: 21; Rodríguez et al. 2005: 559; Rodríguez et al. 2006: 154; García-Madrigal & Andréu-Sánchez 2009: 31, fig. 3B; Mantelatto et al. 2011: 373; Moscoso 2012: 79; Poupin & Lemaitre 2014: 14, fig. 3B, C; Ferreira & Melo 2016: 185 , fig. 2E; Hiller & Lessios 2017: 1; Diez & Lira 2017: 446 ; Poupin 2018: 149; Mantelatto et al. 2021: 570 , fig. 2G.

Not Petrolisthes armatus . — Boone 1930: 73, pl. 19; Boone 1931: 151, fig. 6 [= Petrolisthes nobilii Haig, 1960 ].

Not Petrolisthes armatus . — Miers 1881: 432 [= Petrolisthes marginatus Stimpson, 1859 ]; Hildebrand 1939: 23 [= Petrolisthes robsonae Glassell, 1945 ].

Porcellana gundlachii Guérin-Méneville 1855 : pl. 11, fig. 6.

Porcellana leporina Heller 1862: 523 ; Heller 1865: 78, pl. 6, fig. 7.

Porcellana digitals Heller 1862: 524 ; Heller 1865: 77, pl. 6, fig. 6.

Petrolisthes digitalis .— Lewinsohn 1976: 66, 68, fig. 1.

Material examined. Panama [Pacific]: 1 ov. female, cl 7.0, cw 6.6 ( FLMNH UF 57136 ), Coiba Is ., Isla Coiba, Bahía Santa Cruz, 7°37’18.3”N, 81°46’06.8”W, mudflat with large rocks exposed at low tide, leg. A. Anker et al., 18.02.2019 (fcn PAN-077); 1 male, cl 12.1, cw 11.4 ( FLMNH UF 57137 ), Azuero Peninsula, Búcaro de Tonosí , near “Casa Iguana”, 7°20’08.4”N, 80°21’12.8”W, rocky plateau with rocks, low tide, leg. M. Leray & P.P.G. Pachelle, 14.02.2019 (fcn PAN-008); 1 male, cl 14.9, cw 13.9 ( FLMNH UF 57138 ), Azuero Peninsula, north of Búcaro de Tonosí , Puerto Vapor (Puerto Cañas), 7°21’41.1”N, 80°21’56.5”W, estuary, outer mudflat, low tide, under dead wood log, leg. P.P.G. Pachelle, 16.02.2019 (fcn PAN-034); 1 male, cl cw indet. ( ULLZ / USNM), Bahía Chame , leg. J. Scioli, 08.2018 [examined by J. Scioli]; 1 male, cl 13.0, cw 12.2 ( MZUSP 33689 ), Playa Farfán near Panama Canal , rocky-muddy intertidal, low tide, leg. A. Anker & J.F. Lazarus-Agudelo, 19.03.2015; 3 ov. females, cl 5.4, cw 4.9, cl 5.0, cw 4.6 and cl 4.2, cw 4.1 ( MZUSP 40075 ), Cuidad de Panamá, Punta Calafati , 08º57’00.1”N – 79º31’41.7ºW, leg. L.R.L. Simone, 28.01.2006; 1 male, cl 8.4, cw 8.1 ( FLMNH UF 57710 ), Las Perlas Is ., Isla Contadora, north of Playa Larga , 8°37’59.4”N, 79°01’52.9”W, rocky reef, under rocks, leg. P.P.G. Pachelle & M. Leray, 22.03.2019 (fcn PP 19-025) . Panama [Caribbean]: 1 male, cl cw indet. ( ULLZ / USNM), Bocas del Toro, leg. J. Scioli, 08.2018 [examined by J. Scioli] .

Previous records from Panama. Haig (1962, 1968, Pacific); Abele & Kim (1989, Pacific); Rodríguez et al. (2005, Atlantic); Mantelatto et al. (2011, Pacific and Atlantic); Hiller & Lessios (2017, Pacific and Atlantic).

Distribution. West Atlantic: USA (Gulf of Mexico to South Carolina), Bermuda, Bahamas, Mexico, Belize, Cuba, Jamaica, Puerto Rico, N and E Lesser Antilles, Costa Rica, Panama (Bocas del Toro, Panama Canal area, Colón, Mira I., Golfo de San Blas, Bahía de Caledonia), Colombia, Venezuela and Brazil from Pará to Santa Catarina and Fernando de Noronha ( Gore 1982; Rodríguez et al. 2005; Poupin & Lemaitre 2014; Ferreira & Melo 2016; Hiller & Lessios 2017; Diez & Lira 2017; present study). East Atlantic: Angola and Senegal ( Chace 1956; Holthuis & Manning 1970; Rodríguez et al. 2005; Hiller & Lessios 2017), record from Gibraltar highly doubtful ( Lewinsohn 1976, see below). Not present in the Central Atlantic (see below). East Pacific: Mexico, El Salvador, Honduras, Nicaragua, Costa Rica, Panama (Coiba Is., Azuero Peninsula, Bahía Chame, Panama Canal area, vicinity of Ciudad de Panamá, including “Recife de Casa de Putas”, Taboga Is., Las Perlas Is.), Colombia and Peru ( Haig 1968; Gore 1982; García-Madrigal & Andréu-Sánchez 2009; Mantelatto et al. 2011; Moscoso 2012; Hiller & Lessios 2017; present study).

Ecology. Largely intertidal and shallow subtidal, typical depth range: around 0–10 m, exceptionally down to 60 m; in great variety of habitats with abundance of shelters, most common on rocky shores, usually on relatively calm, less exposed shores, also in oyster and mussel beds, sandy reefs built by sabellariid polychaetes, Phragmatopoma spp. , and mangroves; found primarily under rocks logs and other debris, also on jetties, among mangrove roots, sometimes in crevices of corals or inside sponges, especially juveniles ( Werding 1977; Williams 1984; Rodríguez et al. 2005; Ferreira & Melo 2016; Poupin 2018; Mantelatto et al. 2021; present study).

Remarks. Petrolisthes armatus ( Figs. 36 , 37 ) is the most widespread and one of the most common species of porcelain crabs in the western Atlantic and is also fairly common on muddy-rocky shores of the eastern Pacific and eastern Atlantic (Mantelatto et al. 2011; Hiller & Lessios 2017). Hiller & Lessios (2017) analysed mitochondrial DNA (including COI) of specimens of P. armatus from throughout its range and found that (1) the species is genetically highly structured and has a limited potential for dispersal; (2) the Atlantic and the Pacific populations separated about 3.5 mya, with the final closure of the Isthmus of Panama; (3) the western and eastern Atlantic populations are genetically distinctive and diverged around 3.1 mya; (4) within the western Atlantic, the populations from the south-eastern USA and Gulf of Mexico are genetically separated from those ranging from the western Caribbean Sea to Brazil; (5) within the eastern Pacific, the populations from Colombia and Ecuador are genetically separated from those distributed further north from Panama to the Gulf of California. Thus, the present consensus is that despite a strong genetic structure, P. armatus represents a single, widespread species, with well-established populations on both coasts of Panama.

An opportunity is taken here to comment on the distribution of P. armatus in the Atlantic Ocean. The species’ range in the eastern Atlantic does not include Gibraltar, contrary to frequent “records” in taxonomic literature (e.g. Haig 1960; Ferreira & Melo 2016). The record of P. armatus from Gibraltar was based on a single specimen described by Heller (1862, 1865) as Porcellana digitalis Heller, 1862 , with the type locality Gibraltar according to the accompanying label written later, possibly by O. Pesta. However, Lewinsohn (1976), placing P. digitalis in the synonymy of P. armatus , already pointed out that “ Gibraltar ” as type locality of the former species is highly unreliable and should be “disregarded, unless supported by new material”. To our best knowledge, P. armatus has never been recollected in Gibraltar and therefore it is very likely that the species does not occur on the African coast north of Senegal. Along the same lines, the record of P. armatus from Ascension Island in the Central Atlantic, often repeated in taxonomic and phylogenetic literature (e.g. Chace 1956; Ferreira & Melo 2016; Hiller & Lessios 2017), was apparently based on a specimen of P. marginatus misidentified as P. armatus by Miers (1881) (see De Grave et al. 2017).

Petrolisthes armatus is morphologically most similar to another eastern Pacific species, P. nobilii Haig, 1960 (see below). The latter species can be easily distinguished by the carapace subtriangular and broader posteriorly; the carapace front slightly narrower and more triangular; the P1 palm broader, with the lateral margin more convex, and with a fringe of short pubescence on the ventral surface ( Haig 1960).

Figures

FIGURE 36. Petrolisthes armatus (Gibbes, 1850), ovigerous female (cl 7.0 mm, cw 6.6 mm) from Coiba Island, Panama (FLMNH UF 57136), dorsal (A) and ventral (B) views [photographs by AA].

FIGURE 37. Petrolisthes armatus (Gibbes, 1850), male (cl cw indet.) from Chame Bay, Panama (ULLZ/USNM), dorsal view; B, male (cl cw indet.) from Bocas del Toro, Panama, (ULLZ/USNM), dorsal view [photographs courtesy of Justin Scioli].