Ranilia muricata H. Milne Edwards, 1837

In, First Published, 2022, Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean, Zootaxa 5146, pp. 1-129 : 20-22

Ranilia muricata H. Milne Edwards, 1837

( Fig. 9A–C )

Ranilia muricata H. Milne Edwards, 1837: 196 .

Ranilia saldanhai H. Rodrigues da Costa, 1970: 33 [Type locality: north of Recife , Pernambuco, 7°55’S, 34°48’W, 26–60 m].

Trindade specimens. 1 specimen (MNRJ unnumbered), R/V “Astro Garoupa”, REVIZEE, Trindade Island, stn C5 R49, 20°31’08.4S, 29°21’03.6W, 10.vii.2001, 57 m [not examined. See below under remarks].

Comparative material examined. Ranilia muricata : Martinique: 1 female ( MZUSP 17301 ) , R/V “Le Noroit”, IGMAR 2 Expedition , stn BI-246, 14°52.68700’N, 61°06.12000’W, 1993, volcanic sand [J. Poupin don.]. 1 female ( MZUSP 17339 ) , ibidem, stn BI-243, 14°53.31700’N, 61°07.6500’W, 1993, volcanic sand [J. Poupin don.]. 1 female ( MZUSP 17331 ) , IGMAR 3 Expedition , stn 415, 14°55.59’N, 61°05.13’W, IFREMER coll., 13.ix.1994, dredge [J. Poupin don.]. Brazil: Espírito Santo: 1 male ( MZUSP 41476 ) , R/V “Marion Dufresne”, TAAF MD55/ Brésil Expedition, Vitória–Trindade Seamount Chain, Davis Bank, stn 23 DC40, 20°39’S, 34°41’W, 15.v.1987, sandy shell, 60 m. Ranilia saldanhai : Brazil: Pernambuco: holotype male, cl 39 mm, cw 33 mm ( MZUSP 8223 ) [junior synonym of R. muricata ], R/V “Almirante Saldanha”, north of Recife , 7°55’S, 34°48’W, 26–60 m.

Distribution. North Carolina, Gulf of Mexico, Caribbean Sea, and Brazil (Pernambuco, Davis Bank in the Vitória–Trindade Seamount Chain, and Trindade Island) ( Melo 1996; Serejo et al. 2006; Felder et al. 2009; Tavares et al. 2017).

Ecological notes. Very little is known about the biology of Ranilia muricata . It has been reported from soft bottoms including sand, loose rubble, and sand and broken shells between 9 and 102 m. Rathbun (1937) reported on crab fragments recovered from fish stomachs. This species is also preyed by the gray tilefish Caulolatilus microps Goode & Bean ( Ross 1982) .

Remarks. Ranilia saldanhai is only known from its holotype (Fig. 9A–C). Rodrigues da Costa (1970) briefly compared R. saldanhai to R. muricata , while mentioning that the two species were morphologycally close to each other. Gomes-Corrêa (1970) uncritically accepted R. saldanhai as a valid species, whereas Goeke (1980) opined that an in-depth comparison between R. saldanhai and R. muricata was necessary. Neither of the two authors examined the holotype of R. saldanhai . Melo & Campos Junior (1994) sunk R. saldanhai into the synonymy of R. muricata upon the examination of the holotype of the former species. We have reexamined the holotype of R. saldanhai and found that the defining characters advanced by Rodrigues da Costa (1970) to support R. saldanhai are not consistent and cannot be used to differentiate R. saldanhai from R. muricata . In the absence of other characters to separate the two species, we agree that R. saldanhai should indeed be considered a junior synonym of R. muricata .

Ranilia muricata is reported here for the first time from the Vitória–Trindade Seamount Chain (Davis Bank). The single specimen reported by Serejo et al. (2006) from the Trindade Island (MNRJ unnumbered) was not found for examination.

Figures

FIGURE 9. A–C, Ranilia saldanhai H. Rodrigues da Costa, 1970, holotype, male, cl 39 mm, cw 33 mm (MZUSP 8223) (junior synonym of R. muricata H. Milne Edwards, 1837). A, Habitus, dorsal view (tip of rostrum broken). B, C, Left cheliped, mesial and lateral view, respectively. D, E, Symethis variolosa (Fabicius, 1793), female, cl 8.9 mm, cw 13.1 mm (MZUSP 41574). D, E, Habitus and detail of anterior region, respectively, dorsal view. Scales: A–D, 10 mm. Photographs (A–C) by J. Colavite.