Petrolisthes tridentatus Stimpson, 1859

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 : 119

Petrolisthes tridentatus Stimpson, 1859

( Fig. 74 , 75 )

Petrolisthes tridentatus Stimpson 1858: 227 (nomen nudum); Stimpson 1859: 75, pl. 1, fig. 4; Schmitt 1935: 187, fig. 47; Haig 1956: 18; Haig 1957b: 8; Haig 1960: 81, pl. 25, fig. 4; Haig 1962: 179; Gore & Abele 1976: 24; Werding 1977: 208, fig. 25; Gore 1982: 20; Werding & Haig 1982: 68; Rodríguez et al. 2005: 567; Hiller et al. 2006: 554; Lazarus-Agudelo & Cantera- Kintz 2007: 230; Diez & Lira 2017: 447 ; Poupin 2018: 151.

Petrolisthes gracilis .— Nobili 1901: 13 [not Petrolisthes gracilis Stimpson, 1859 ].

Petrolisthes eriomerus .— Boone 1931: 154 (part.) [not Petrolisthes eriomerus Stimpson, 1871 ].

Material examined. None from Panama. Extra-limital material. French Antilles : 1 male, cl cw indet. ( FLMNH UF 32075 ), Saint Martin, sta. STM-034, Baie du Cul-de-Sac , near Etang de la Barrière , 18°06’14.4”N, 63°01’26.4”W, seagrass sieving, leg. A. Anker et al., 15.04.2012 (fcn BSTM-0701); 1 ov. female, cl cw indet. ( FLMNH UF 32376 ), Saint Martin, sta. STM-050, Le Gallon, 18°04’47.0”N, 63°00’54.5”W, inner side, seagrass/rubble mats, depth 1–3 m, leg. A. Anker & J.P. Marechal, 21.04.2012 (fcn BSTM-1393); 1 male, cl cw indet. ( FLMNH UF 31932 ), Saint Martin, Sta. STM-013, off Mont Vernon, south of Petite Clef Island (“Little Key”), 18°05’59.3”N, 63°01’18.3”W, depth 0–2 m, leg. J. Slapcinski et al., 11.04.2012 (fcn BSTM-0345) .

Previous records from Panama. Schmitt (1935, Pacific); Haig (1956, Atlantic); Haig (1957b, Pacific); Gore & Abele (1976, Pacific); Gore (1982, Pacific); Rodríguez et al. (2005, Atlantic).

Distribution. West Atlantic: Mexico, Honduras, Bahamas, Cuba, Jamaica, N, E and S Lesser Antilles, Panama (Bahía de Caledonia), Colombia and Venezuela ( Rodríguez et al. 2005; Poupin 2018; A. Anker, pers. obs.). East Pacific: Costa Rica, Nicaragua, Panama (Bahía Honda in Veraguas, Taboga Is., Las Perlas Is., Punta Guayabo Chiquito in Darién), Colombia and Ecuador ( Haig 1960; Gore & Abele 1976; Gore 1982; Rodríguez et al. 2005).

Ecology. Intertidal and shallow subtidal, known depth range: 0–20 m; typically on rocky shores, in small interstices under rocks and in tide pools ( Werding & Haig 1982; Poupin 2018); two of the Saint Martin specimens were found in seagrass-rubble mats (present study).

Remarks. Petroliosthes tridentatus was originally described from the E Lesser Antilles ( Barbados and Saint Thomas) and is currently considered as a transisthmian species, although as Gore (1982) noted, “it is by far the more abundant in the Pacific, according to available collecting records”. It can be distinguished from the closely related species, especially P. quadratus , by the anteriorly protruding, rounded lateral lobes. The species seems to be quite variable in the colour pattern. Stimpson (1859) noted that in the type specimens, the carapace was spotted with red and streaked down the middle with whitish, the P1 were dark reddish and the P2–P4 were banded. The carapace and P1 of the specimens from Saint Martin and Honduras (Utila) range from dark greenish brown with very few white spots ( Fig. 74C ) or a mixture of brown and pale brown with more numerous white spots ( Fig. 74A ), to white or pale background with more or less numerous dark brown spots and blotches ( Fig. 74D, E , 75A, C ); however, the carpi and propodi of P2–4 are always white with contrasting pale to dark brown transverse bands ( Figs. 74 , 75 ).

Figures

FIGURE 74. Petrolisthes tridentatus Stimpson, 1859: A, B, extra-limital specimen, male (cl cw indet.) from Saint Martin (FLMNH UF 32075), dorsal (A) and ventral (B) views [photographs by AA]; C, extra-limital specimen, male from Saint Martin (FLMNH UF 31932), dorsal view [photograph courtesy of Gustav Paulay / François Michonneau]; D, extra-limital specimen, ovigerous female (cl cw indet.) from Utila, Honduras (not deposited), dorsal view; E, extra-limital specimen, male (cl cw indet.) from the same locality (not deposited), dorsal view [photographs by AA].

FIGURE 75. Petrolisthes tridentatus Stimpson, 1859: A–C, extra-limital specimen, ovigerous female (cl cw indet.) from Saint Martin (FLMNH UF 32376), dorsal (A), ventral (B) and frontal (C) views [photographs by AA].