Pylopagurus discoidalis ( A. Milne-Edwards, 1880 )

Nucci, Paulo Ricardo & Melo, Gustavo Augusto Schmidt De, 2011, Hermit crabs from Brazil: Family Paguridae (Crustacea: Decapoda: Paguroidea), except Pagurus, Zootaxa 3104, pp. 26-41 : 37-38

Pylopagurus discoidalis ( A. Milne-Edwards, 1880)

( Figs 1 M, 2M, 3M)

Eupagurus discoidalis A. Milne-Edwards, 1880:41 .

Pylopagurus discoidalis . — A. Milne-Edwards & Bouvier, 1893: 76, pl.6, figs 7–14. — Williams, 1965: 134, fig. 109; 1984: 226, fig. 162. — McLaughlin, 1981: 2. — Coelho & Ramos-Porto, 1986: 43. — Rieger, 1998: 416. — Melo, 1999: 144, fig. 86. — McLaughlin & Lemaitre, 2001: 451, figs 4–6. — McLaughlin et al., 2010: 35.

Material examined. Brazil: Amapá – Proj. Geomar, st. 206, 1 spec. (DOUFPE-3805); 172 m, 2 spec. (MZUSP- 8909). Rio de Janeiro – Cabo Frio, 300-400 m, 9 spec. (MZUSP-13761). São Paulo – Proj. REVIZEE, st. 6659, 2 spec. (MZUSP-13866); st. 6660, 2 spec. (MZUSP-13883); 16 spec. (MZUSP-13772); st. 6665, 3 spec. (MZUSP- 13889). Santa Catarina – Proj. REVIZEE, st. 6786, 1 spec. (MZUSP-13857).

Diagnosis. Shield slightly longer than broad; rostrum triangular, often terminating in small spinule. Ocular peduncles short, corneas dilated; ocular acicles triangular, acute, unornamented. Right cheliped with chela subcircular; dactyl with dorsal surface flattened or slightly convex, smooth, granular or spinulose; palm and fixed finger with dorsal surface somewhat concave or flattened, smooth, granular or spinulose. Left cheliped with propodal-carpal articulation perpendicular; dactyl unornamented; palm and fixed finger circumscribed by low crenulate ridge. Ambulatory legs compressed laterally, similar from left to right; dactyls short, with very long terminal claws; dorsal margins each with row of widely spaced protuberances and spiniform bristles; ventral margins each with 4–6 corneous spines. Telson with posterior lobes separated by small median cleft; terminal margins oblique, each armed with 2–4 moderately strong spines interspersed with smaller spines or spinules.

Distribution. Western Atlantic: United States (North Carolina to Florida), Gulf of Mexico, Antilles and Brazil (Amapá to Santa Catarina).

Habitat. Mostly in shells of Dentalium (Mollusca: Scaphopoda), but also in tubes of annelids. Between 60 and 930 m depth.

Remarks. McLaughlin & Lemaitre (2001) noted that this species shows a wide variation in the morphology and coloration of the right cheliped, and this variation is correlated with ecological and environmental factors.

Figures

FIGURE 1. Shield and cephalic region: A, Agaricochirus gibbosimanus; B, Anisopagurus bartletti; C, Catapagurus sharreri; D, Goreopagurus lemaitrei; E, Iridopagurus iris; F, I. reticulatus; G, I. violaceus; H, Nematopaguroides fagei; I, N. pusillus; J, Phimochirus holthuisi; K, P. occlusus; L, Propagurus gaudichaudii; M, Pylopagurus discoidalis; N, Rhodochirus rosaceus; and O, Tomopagurus wassi. (In B and I the scale corresponds to the length of the shield).