Cancellus ornatus Benedict, 1901

Nucci, Paulo Ricardo & Melo, Gustavo Augusto Schmidt De, 2015, Hermit crabs from Brazil: Family Diogenidae (Crustacea: Decapoda: Paguroidea), except Paguristes, Zootaxa 3947 (3), pp. 327-346 : 329-330

Cancellus ornatus Benedict, 1901

( Figs 1 C, 5C)

Cancellus ornatus Benedict, 1901b: 772 , figs 1, 2.— Alcock, 1905: 167 [list].— Gordan, 1956: 306 [list].— Russell, 1962: 19.— Mayo, 1973: 18, figs 5–8.— Williams, 1984: 193, fig. 134.— Coelho & Ramos-Porto, 1986: 49.— Rieger, 1998: 421.— Melo, 1999: 44, fig. 4.—McLaughlin et al., 2010: 19.

Cancellus calypso Forest & Saint Laurent, 1968: 96 , figs 54–59.

Material examined. Brazil: Pernambuco—Tamandaré, 1 spec. (DOUFPE—3681). Rio de Janeiro—Proj. Monitoramento, st. 3, 1 spec. (MZUSP-13880).

Diagnosis. Shield slightly broader than long, with lateral margins strongly convex. Ocular peduncles approximately 2/3 length of shield, slightly turned outer. Antennal flagella short, slightly longer than ocular peduncles. Anterodorsal region of dactyl, propodus and merus of first ambulatory legs and chelipeds forming an operculum; irregular transverse rows of tubercles on opercular face. First ambulatory legs with opercular face slightly concave on carpus and propodus, dactylus planar. Second ambulatory legs with lateral face of merus and propodus longer than twice the width of these segments. Sixth abdominal tergite broadly hexagonal, length 2/3 width. Anterior lobe larger than posterior. Telson broader than long; two anterolateral depressions on either side in front of raised central area.

Distribution. Western Atlantic—North Carolina, Florida, Bahamas, Gulf of Mexico, Antilles, north of South America and Brazil (from Pernambuco to Rio de Janeiro).

Remarks. Found at depths of 30– 350 m. In Brazil, the genus Cancellus is represented only by C. ornatus whose nearest relative is C. viridis from Caribbean Sea. The use of limestone, calcareous algae, sponges and coral as shelter, hinders the recognition of possible new species, because field collectors, expecting to find hermit crabs in gastropod shells, may unknowingly discard Cancellus specimens.

Figures

FIGURE 1. Shield and cephalic region: A, Areopaguristes iris; B, Calcinus tibicen; C, Cancelus ornatus; D, Clibanarius antillensis.