Petrochirus diogenes (Linnaeus, 1758)

(Figs 4 B, 7B)

Cancer diogenes Linnaeus, 1758: 631 .

Cancer bahamensis Herbst, 1791: 30 .

Pagurus granulatus Olivier, 1811: 640; Dana, 1852: 453.

Petrochirus granulatus .— Heller, 1865: 85.— Smith, 1869: 17, 38.— Moreira, 1901: 23, 85.

Petrochirus bahamensis .— Benedict, 1901a: 140.— Schmitt, 1935: 206, fig. 66.— Provenzano, 1959: 378, fig. 8.

Petrochirus diogenes. — Holthuis, 1959: 151.— Provenzano, 1961: 153.— Williams, 1965: 122, fig. 98; 1984: 198, fig. 138.— Forest & Saint Laurent, 1968: 95.— Provenzano, 1968: 147, figs 1–12.— Coelho & Ramos-Porto, 1986: 49.— Rieger, 1998: 423.— Melo, 1999: 92, fig. 46.—McLaughlin et al., 2010: 23.

Material examined. Brazil: Rio de Janeiro—Ilha Grande, 1 spec. (MZUSP-4609). São Paulo—Ubatuba, 1 spec. (MZUSP-4612); Proj. Integrado, st. Fixa 5, 1 spec. (MZUSP-8728); São Sebastião, 1 spec. (MZUSP-609); Praia Siriúba, 1 spec. (MZUSP-8861); Ilha Vitória, 1 spec. (MZUSP-610); Ilha da Moela, 1 spec. (MZUSP-7516).

Diagnosis. Shield flattened, approximately as broad as long, rough, with scattered tufts of setae. Ocular peduncle straight, moderately dilated distally, with tuft of setae above cornea. Antennular peduncle as long as or slightly longer than ocular peduncle. Chelipeds massive, the right slightly stronger than left; propodi and carpi with grouped tubercles separated by setae at dorsal region; fingers opening obliquely. Left cheliped with finger tips spoon shaped. Carpus of first and second ambulatory legs with ornamentation similar to chelipeds.

Distribution. Western Atlantic—North Carolina to Gulf of Mexico, Antilles Venezuela, Suriname, Brazil (from Amapá to Rio Grande do Sul) and Uruguay.

Remarks. This species probably was the first hermit crab described by using binomial system and named by Linnaeus (1758) of Cancer diogenes . It is also the largest species of marine hermit crab of the world.