(Figs. 1 A, 2 A, 3 A, 4 A)
Eupagurus brevidactylus Stimpson, 1858: 237 [nomen nudum]; 1859: 45; 1862: 91. ― Alcock, 1905: 181.
Pagurus brevidactylus.— Gordan, 1956: 327.— Fausto-Filho, 1970 b: 71; 1974: 9.― Felder, 1973: 26, fig. 6.― McLaughlin, 1975: 360, figs 1–3.― Camp et al., 1977: 29. ― Heck, 1977: 339.― Markham, 1977: 134.― 1978: 112; 1979: 526.― Felder & Chaney, 1979: 10.― Markham & McDermott, 1980: 1271.― Lemaitre et al., 1982: 675.― Coelho & Ramos-Porto, 1986: 40.― Rieger, 1998: 413.― Melo, 1999: 122, fig. 66.
Pagurus miamensis Provenzano, 1959: 414, fig. 21; 1960: 119; 1961: 158.― Coelho, 1964: 255.― Hazlett, 1966: 63; 1972: 820.― Markham, 1972: 71.― Pequegnat & Ray, 1974: 43.
? Pagurus brevidactylus. ― Coelho, 1964: 255.
Pagurus miamensis miamensis. ― Forest & Saint Laurent, 1968: 116, 124, figs 97, 98.― Coelho & Ramos, 1972: 164.― McLaughlin, 1974: 41.
Pagurus miamensis uncifer. ― Forest & Saint Laurent, 1968: 122, figs 78, 79, 95, 98.― Fausto-Filho, 1970 b: 71.― Coelho & Ramos, 1972: 164.― Scelzo & Boschi, 1973: 214.― McLaughlin, 1974: 41.
Pagurus brevidactilus. ― Scelzo & Boschi, 1973: 214.
Pagurus annulipes.— Sánchez & Campos, 1978: 41, fig. 13.
non Pagurus brevidactylus; Provenzano, 1959: 412, fig. 20.― Williams, 1965: 132, fig. 107.― Forest & Saint Laurent, 1968: 116, 121.― McLaughlin, 1974: 41.― Mercando & Lytle, 1980: 338 [= Pagurus caroliniensis McLaughlin].
Diagnosis. Shield longer than broad. Rostrum short, triangular or rounded, unarmed; lateral projections with or without small marginal or submarginal spine. Ocular peduncles long, slender, with corneae slightly dilated. Ocular acicles broad, terminal margins with 3–6 acute spines. Antennular peduncles long, as long as or slightly longer than ocular peduncles. Antennal peduncles equaling or slightly exceeding length of ocular peduncles; setae short, less than 1 article in length. Right cheliped larger than left; palm with single or double row of spines or spinulose tubercles on dorsomesial margin, dorsal surface slightly convex, with short setae and irregular rows of strong acute spines (females and small males), or irregular rows of small spines or tubercles (large males). Dorsomesial and dorsolateral margins of carpus with row of strong spines. Left cheliped reaching to base of dactyl of right cheliped, often longest in females; dactyl usually exceeding length of palm, dorsal surface with row of moderately strong spines, all surfaces with scattered long setae, particularly dense along cutting edge; palm one-third to one-half length of carpus, with irregular double row of strong spines extending onto fixed finger as single row; carpus equaling or slightly exceeding length of merus, dorsolateral margin with row of moderately strong spines, distal margin with 1 or 2 prominent acute spines; merus subtriangular. Second and third pereopods with dactyls shorter than propodi, terminating in strong corneous claws; ventral margins with row of strong corneous spines increasing in size distally; dorsal surfaces of propodi each with row of tufts of long setae, ventral surfaces each with row of tufts of long setae and few corneous spines or spinules distally; distal margins of carpi each with moderately strong spine. Telson somewhat asymmetrical with posterior lobes subtriangular, separated by median cleft, terminal margins armed with several strong spines and few small spines.
Distribution. Western Atlantic — Bermuda, Florida, Gulf of Mexico, Antilles, Central America, northern South America and Brazil (Fernando de Noronha and from Pernambuco to Santa Catarina).
Habitat. Shallow waters to 50 metres, on sandy and rocky substrates, and algae banks.
Material examined. Brazil: Pernambuco — Fernando de Noronha, Ponta da Sapata, 1 male: 1.8 mm, 1 female: 1.7 mm ( MZUSP – 9440). Bahia — Alcobaça, Parcel das Paredes, 2 males: 1.4, 1.5 mm ( MZUSP – 13911). Rio de Janeiro — Angra dos Reis, 5 males: 2.9, 2.3, 2.1, 2.9, 2.1 mm, 5 females: 2.5, 2.6, 2.5, 2.8, 2.7 mm ( MZUSP – 4600). São Paulo — São Sebastião, Saco Grande, 1 male: 2.3 mm, 1 female: 2.1 mm ( MZUSP – 13006); Guarujá, Praia de Pernambuco, 1 female: 1.8mm ( MZUSP – 7291); 1 male: 2.3 mm ( MZUSP – 7290).
Remarks. Pagurus brevidactylus is very close to P. provenzanoi, but the two species can be quickly distinguished. Pagurus provenzanoi has short dense setae on the dorsal face of the chelipeds, whereas P. b re v i - dactylus has one longitudinal row of strong spines next to the dorsolateral margin of the left cheliped, and very short setae on the antennal flagellum.