Petrolisthes polymitus Glassell, 1937

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 : 112

Petrolisthes polymitus Glassell, 1937

( Figs. 69 , 70 )

Petrolisthes polymitus Glassell 1937: 81 , pl. 1, fig. 1.; Haig 1960: 41, pl. 22, fig. 1; Haig 1962: 176; Haig 1968: 57, 61; Gore & Abele 1976: 24; Gore 1982: 18; Werding & Haig 1982: 68; Hickman & Zimmerman 2000: 65, unnumbered colour photograph; García-Madrigal & Andréu-Sánchez 2009: 37, fig. 4F.

Material examined. Panama [Pacific]: 1 female, cl 4.5, cw 4.7 ( FLMNH UF 57718 ), Coiba Is ., Isla Afuerita , northeastern bay, 7°42’16.7”N, 81°38’04.4”W, depth 0.5–1 m, shallow subtidal flat with rocks, corals and coral rubble, under rocks and in crevices of coral rubble, leg. A. Anker, 23.02.2018 (fcn PAN-249); 2 ov. females, cl 3.8, cw 3.9 and cl 4.0, cw 4.1 ( MZUSP 33956 ), Las Perlas Is ., Isla Bartolomé , depth 0–1 m, in crevices of rocks, dead and living corals, under large rocks on coarse sand, leg. A. Anker, J. Luque, A.R. Palmer & T. Kaji 19.04.2015; 1 ov. female, cl 4.3, cw 4.2 ( MZUSP 33453 ), Punta Mala, rocky intertidal, leg. A. Anker & J.F. Lazarus-Agudelo, 23.03.2015; 1 male, cl 4.0, cw 3.9, 2 ov. females, cl 4.2, cw 4.1 and cl 3.9, cw 3.7 ( MZUSP 33454 ), same collection data as for previous specimen .

Previous records from Panama. Haig (1960, 1962); Gore & Abele (1976).

Distribution. East Pacific: Mexico, Costa Rica, Panama (Coiba Is., Secas Is., Punta Mala, Taboga Is., Las Perlas Is.), Colombia and Ecuador (including Galápagos) ( Haig 1960; Gore & Abele 1972; present study).

Ecology. Intertidal and subtidal, presently known depth range: 0–15 m; under rocks, in rock crevices, in dead and living corals ( Pocillopora ) ( Haig 1960; García-Madrigal & Andréu-Sánchez 2009; present study).

Remarks. Petrolisthes polymitus can be readily recognised in the field by its contrasting dark-and-white colour pattern, the dark part varying from dark-brown or almost black to greenish-brown ( Figs. 69 , 70 ; see also Hickman & Zimmerman 2000). The younger individuals are less contrasting than adults (or at least with fewer white areas), however, they may be more colourful, with tinges of purple, green and reddish ( Fig. 69A, B ). The Mexican specimen illustrated by García-Madrigal & Andréu-Sánchez (2009) was photographed shortly after preservation and therefore is reddish-and-white, but still preserving some of its original pattern.

Figures

FIGURE 69. Petrolisthes polymitus Glassell, 1937: A, B, ovigerous female (cl 4.0 mm, cw 4.1 mm) from Las Perlas Islands, Panama (MZUSP 33956), dorsal (A) and ventral (B) views [photographs by AA].

FIGURE 70. Petrolisthes polymitus Glassell, 1937: A, male (cl cw indet.) from Ciudad de Panamá, Panama (not deposited), dorsal view; B, C, female (cl 4.5, cw 4.7) from Isla Afuerita, Coiba Archipelago, Panama (FLMNH UF 57718), dorsal (B) and ventral (C) views [photographs by AA].