Polyonyx gibbesi Haig, 1956

Ferreira, Luciane Augusto De Azevedo & Melo, Gustavo Augusto Schmidt De, 2016, Porcelain crabs from Brazil (Crustacea: Decapoda: Anomura: Porcellanidae), Zootaxa 4092 (2), pp. 175-194 : 189-190

Polyonyx gibbesi Haig, 1956

( Fig. 3 B)

Porcellana macrocheles Gibbes, 1850: 191 ; 1854: 6, pl. 1, fig. 5 [non Porcellana macrocheles Poeppig, 1836 ]. Polyonyx macrocheles— Stimpson, 1858: 229.

Polyonyx gibbesi— Haig, 1956: 28 (type-locality: South Carolina, USA).

Material examined. Brazil: Rio de Janeiro—Angra dos Reis, 5 males, 2 females, 6 ovigerous females (MNRJ- 3787). São Paulo—São Sebastião, Praia do Araçá, 2 males, 2 females, 2 ovigerous females (MZUSP-6962). Paraná—Saco do Limoeiro, 1 ovigerous female (MZUSP-12763). No locality— 1 male, 1 ovigerous female (MZUSP-7146).

Recognition characters. Carapace subrectangular, about 3 times broader than long; smooth, except for discrete rugae on posterolateral margin; strongly convex; epibranchial angle well-produced. Front with straight margin. Chelipeds subequal, subcylindrical; propodus twisted, compressed, more evident on minor cheliped, fringed with long setae on extensor margin; fingers short, grooved and crenulate on cutting face. Walking legs smooth, compressed, pubescent; ischium with row of distal spinules on flexor margin; propodus with row of 3 spines on flexor margin, dactylus short, ending in a curved, two spines claw, flexor margin with 2 spines, smaller than terminal claw. Gonopods present in males. Telson composed of 7 plates.

Habitat. A common commensal of polychaetes, living in pairs and, rarely, found outside their tubes. From the intertidal zone down to depths of 47 m (Williams 1984), on rocks, sand and mud from sublittoral region (Veloso 1999).

Geographic distribution. Western Atlantic—USA, Massachusetts, Rhode Island, North and South Carolina, eastern and western Florida, Texas; Panama, Caledonia Bay; Cuba; Puerto Rico; Trinidad; Venezuela, Punta Papuy; Brazil (from Ceará to Rio Grande do Sul); Uruguay, La Paloma; and Argentina, Mar del Plata.

Remarks. According to Rodríguez et al. (2005), Polyonyx gibbesi is the only species of the genus that occurs in the western Atlantic.

Figures

FIGURE 3. Preserved specimens, dorsal view. A, Polyonyx gibbesi Haig, 1956, male (MZUSP- 7146); B, Pisidia brasiliensis Haig in Rodrigues da Costa, 1968, male (MZUSP- 11300); C, Porcellana sayana (Leach, 1820), male (MZUSP- 13727); D, Porcellana sigsbeiana A. Milne-Edwards, 1880, male (USNM- 35401). Scales: A, C – D (5 mm); B (1 mm).