Petrolisthes galathinus ( Bosc, 1802 )

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 : 81-87

Petrolisthes galathinus ( Bosc, 1802) [s. lat.]

( Figs. 46–48 , 91A )

Porcellana galathina Bosc 1802: 233 , pl. 6, fig. 2.

Porcellana sexspinosa Gibbes 1850: 190 .

Petrolisthes sexspinosus . — Stimpson 1858: 227; Benedict 1901: 133.

Petrolisthes galathinus . — Ortmann 1897: 283; Rickner 1975: 164; Gore & Abele 1976: 21; Werding 1977: 201, fig. 20; Werding 1983: 410, fig. 3; Williams 1984: 243, fig. 178; Abele & Kim 1989: 21; Rodríguez et al. 2005: 561; Rodríguez et al. 2006: 154; Hiller et al. 2006: 548; Poupin & Lemaitre 2014: 17 (part.), fig. 3F (not fig. 3G, see below); Ferreira & Melo 2016: 186 , fig. 2F; Poupin 2018: 149; Mantelatto et al. 2021: 570 , fig. 2H.

Not Petrolisthes galathinus . — Poupin & Lemaitre 2014: 17 (part.), fig. 3G [= Petrolisthes aff. galathinus , see below].

Not Petrolisthes galathinus . — Hiller et al. 2004: 5; Lazarus-Agudelo & Cantera-Kintz 2007: 230 [= Petrolisthes occidentalis Stimpson, 1859 ].

Petrolisthes caribensis . — Rodríguez et al. 2005: 561, pl. 1, fig. G [not Petrolisthes caribensis Werding, 1983 , see above].

Material examined. Panama [ Caribbean ]: 1 female, cl 5.1, cw 4.5 ( MZUSP 33894 ) , Bocas del Toro, southern end of Isla Bastimentos, Cayo Coral (= Crawl Cay ), depth 0.5–2 m under corals and in coral rubble, leg. A. Anker, J. Luque, A.R. Palmer & T. Kaji, 28.04.2015; 1 female, cl 6.1, cw 5.7 ( FLMNH UF 57144 ) , Bocas del Toro , between Isla Bastimentos and Isla Solarte , 9°20’18.7”N, 82°13’02.8”W, depth less than 2 m, in dead corals, leg. P.P.G. Pachelle, 29.03.2019 (fcn PP 19-119); 1 female, cl 11.2, cw 11.1 ( MZUSP 33896 ) , Bocas del Toro , Isla Colón, Boca del Drago , shallow flat with seagrass and abundant fragmented coral rubble and large coral rocks, depth 0.5–2 m, under and in crevices of coral rubble, leg. A. Anker, J. Luque, A.R. Palmer & T. Kaji, 01.05.2015; 1 male, cl cw indet. ( ULLZ / USNM) , Bocas del Toro , leg. J. Scioli, 08.2018 [examined by J. Scioli]; 2 females, cl 5.9, cw 5.7 and cl 7.1, cw 6.8 ( MZUSP 40069 ) , Isla Grande , western point, coral reef, depth 0.5–2 m, in reef crevices, leg. Anker et al., 30.07.2018. Extra-limital material . USA [ Florida ]: 1 female, cl cw indet. ( FLMNH UF 14655 ) , Florida Keys, Little Duck Key, Gulf of Mexico side, depth 1–2 m, leg. A. Anker et al., 06.09.2008; 1 male, cl cw indet. ( FLMNH UF 19688 , FLMNH UF 19680 ) , Florida Bay north of Florida Keys , R/ V Bellows sta. 7, 81 51.967’W, 24 53.561’N, otter trawl over algae-sponge bottom, 16 m, leg. A. Anker et al., 07.06.2009 (fcn KEYS-098, KEYS-108) .

Comparative material. Petrolisthes aff. galathinus form A. French Antilles: 1 ov. female, cl cw indet. (FLM- NH UF 32191), Saint Martin, Sta. STM-038, Ilôt de l’Embouchure, 18°04’01.2”N, 63°00’43.2”W, reef, depth 0–1 m, leg. A. Anker et al., 17.04.2012 (fcn BSTM-0961); 1 female, cl cw indet. ( FLMNH UF 32192 ), same collection data as for previous specimen (fcn BSTM-0962) ; 1 female, cl cw indet. (1 cheliped missing) ( FLMNH UF 32515 ), Saint Martin, Sta. STM-062, Caye Verte Island, 18°05’09.0”N, 63°00’40.1”W, reef with sand and seagrass, depth 1–10 m, leg. A. Anker et al., 25.04.2012 (fcn BSTM-1727). Petrolisthes aff. galathinus form B. French Antilles : 1 female, cl cw indet. ( FLMNH UF 32557 ), Saint Martin, Caye Verte Island , 18°05’09.0”N, 63°00’40.1”W, reef with sand and seagrass, depth 1–10 m, leg. A. Anker et al., 25.04.2012 (fcn BSTM-1852) ; 1 male, cl cw indet. ( FLMNH UF 32502 ), Saint Martin, Sta. STM-060, Pinel Island, 18°06’26.7”N, 63°01’02.2”W, reef, depth 1.5–7 m, leg. G. Paulay et al., 24.04.2012 (fcn BSTM-1711) .

Previous records from Panama. Abele & Kim (1989); Rodríguez et al. (2005).

Distribution. West Atlantic: USA (Florida), Mexico, Belize, Panama (Bocas del Toro, Panama Canal area, Colón, Punta Galeta, Isla Grande, Bahía de Caledonia), Cuba, Jamaica, Puerto Rico, N, E and S Lesser Antilles, Colombia, Venezuela, Suriname, French Guyana and Brazil from Pará to São Paulo (e.g. Williams 1984; Rodríguez et al. 2005; Hiller et al. 2006; Poupin & Lemaitre 2014; Ferreira & Melo 2016; Mantelatto et al. 2021; present study).

Ecology. Intertidal and subtidal, known depth range 0–50 m, possibly deeper; in great variety of habitats, most common on coral reefs and associated coral rubble fields, seagrass meadows with rubble, rocky shores; under rocks, among sponges, in crevices of corals, occasionally associated with sea anemones ( Haig 1960; Williams 1984; present study).

Remarks. Petrolisthes galathinus was briefly described and illustrated by Bosc (1802) as Porcellana galathina Bosc, 1802 , based on material from an unknown locality, possibly in the south-eastern USA, although Bosc’s original statement was “on ignore son pays natal”. The single figure provided by Bosc (1802: pl. 6, fig. 2), a handcoloured lithograph of the habitus in dorsal view, is very superficial, essentially depicting a spotted porcelain crab. Gibbes (1850) described apparently the same species in more details under Porcellana sexspinosa Gibbes, 1850 , which was later synonymised with P. galathinus . To the present date, P. galathinus remains one of the taxonomically most challenging, morphologically poorly defined porcellanid taxa ( Werding & Hiller 2002; Hiller et al. 2006). A large part of the colour variation reported for P. galathinus , e.g. by Benedict (1901, as P. sexspinosus ), Rickner (1975), Werding (1977), Williams (1984), Abele & Kim (1989), Hiller et al. (2006) and Poupin & Lemaitre (2014), appears to be part of possibly still ongoing cryptic speciation in what is now known as the P. galathinus species complex ( Werding 1983; Werding & Hiller 2002; Hiller et al. 2006).

Werding (1977) stated that colouration of P. galathinus changes with age, from greyish-brown in smaller crabs to purplish-brown in almost all larger individuals, which is partly seen in some material from Panama ( Figs. 46 , 47 ) and Florida ( Fig. 48 ). At least some specimens dredged in the Gulf of Mexico off western coast of Florida (e.g. FLMNH UF 28260) or collected on shallow-water reefs in the Florida Keys (FLMNH UF 26191) are brightly coloured and have very conspicuous transverse piliferous ridges on the carapace, and probably represent P. galathinus sensu Bosc (1802) . Noteworthy, some specimens from Panama identified herein as P. galathinus [s. lat.] ( Fig. 47B, C ) have colour patterns that are similar to that of some specimens from western Florida, but not to the striped brightcoloured ones (cf. Fig. 48 ). Whether the Panamanian material identified herein as P. galathinus [s. lat.] actually represents P. galathinus sensu Bosc (1802) will need to be shown by more careful morphological and molecular analyses, following a full redescription of P. galathinus .

Hiller et al. (2006: Tab. 3) listed four colour variants of P. galathinus , as P. galathinus “pres.”, “White Teeth”, “Spots” and “Stripes”. All of them are supported by molecular data and likely represent distinct, cryptic or pseudocryptic species. Unfortunately, these colour variants, just like P. caribensis “Blue ” (see above), were not illustrated by Hiller et al. (2006), making the current assignments rather tentative. One of them is a very conspicuous and brightly coloured porcelain crab that occurs in the French Antilles ( Fig. 49 ; see also Poupin & Lemaitre 2014: fig. 3G), Honduras and Cayman Islands (A. Anker, pers. obs.), which is herein referred to as “ P. aff. galathinus form A”. The other colour variant from the French Antilles has a colour pattern somewhat reminiscent of P. caribensis ( Fig. 50 ), in addition to the presence of four spines on the P2–4 dactyli (vs. three in other species of the P. galathinus ); this form herein referred to as “ P. aff. galathinus form B”. Both of these colour variants, especially the more common P. sp. aff. galathinus form A, seem to be present in Colombia ( Hiller et al. 2006) and may therefore also occur on offshore islands of Panama ( Table 1). In all likelihood, they represent two further undescribed species of Petrolisthes (see also under P. aff. caribensis ). However, we feel that the description of all new taxa within the P. galathinus complex should be reserved to their discoverers ( Hiller et al. 2006).

Figures

FIGURE 46. Petrolisthes galathinus (Bosc, 1802) [sensu lato]: A, B, female (cl 5.1 mm, cw 4.5 mm) from Bocas del Toro, Panama (MZUSP 33894), dorsal (A) and ventral (B) views [photographs by AA].

FIGURE 47. Petrolisthes galathinus (Bosc, 1802) [sensu lato]: A, female (cl 11.2 mm, cw 11.1 mm) from Bocas del Toro, Panama (MZUSP 33896), dorsal view [photograph by AA]; B, young specimen of unknown sex (cl cw indet.) from Bocas del Toro, Panama (ULLZ/USNM), dorsal view [photograph courtesy of Justin Scioli]; C, female (7.1 mm, cw 6.8 mm) from Isla Grande, Panama (MZUSP 40069), dorsal view [photograph by AA].

FIGURE 48. Petrolisthes galathinus (Bosc, 1802) [sensu stricto]: A–D, extra-limital specimens, two males (cl cw indet.) from Florida Bay, USA (FLMNH UF 19688, 19680), dorsal (A, C) and ventral (B, D) views of the same specimen; E, extra-limital specimen, female (cl cw indet.) from Little Duck Key, Florida Keys, USA (FLMNH UF 14655), dorsal view [photographs by AA].

FIGURE 49. Petrolisthes aff. galathinus (Bosc, 1802), form A: A–C, extra-limital specimen, ovigerous female (cl cw indet.) from Saint Martin (FLMNH UF 32191), dorsal (A), ventral (B) and frontal (C) views [photographs by AA].

FIGURE 50. Petrolisthes aff. galathinus (Bosc, 1802), form B: A, B, extra-limital specimen, male (cl cw indet.) from Saint Martin (FLMNH UF 32502), dorsal (A) and frontal (C) views [photographs by AA].

FIGURE 91. Some westernAtlantic Porcellanidae (species reported from Panama) photographed in situ:A, Petrolisthes galathinus (Bosc, 1802) [sensu lato], Tayrona, Colombia; B, C, Porcellana sayana (Leach, 1820), southern Florida, USA [photographs courtesy of Juan-Felipe Lazarus-Agudelo (A) and Linda Ianniello (B, C)].