Pylopagurus discoidalis ( A. Milne-Edwards, 1880 )

Lemaitre, Rafael & Tavares, Marcos, 2015, New taxonomic and distributional information on hermit crabs (Crustacea: Anomura: Paguroidea) from the Gulf of Mexico, Caribbean Sea, and Atlantic coast of South America, Zootaxa 3994 (4), pp. 451-506 : 496

Pylopagurus discoidalis ( A. Milne-Edwards, 1880)

( Fig. 1 E)

Eupagurus discoidalis A. Milne-Edwards, 1880: 41 (type locality: USCSS Blak e, sta 157, off Monserrat, Caribbean Sea, Lesser Antilles).

Pylopagurus discoidalis .— Coelho, 1971: 232.— Coelho & Ramos, 1973: 166.— Coelho & Santos, 1980: 143.—Coelho & Ramos-Porto, 1987: 43.— Rieger, 1998: 416.— Melo, 1999: 144, figs 85, 86.—McLaughlin & Lemaitre, 2001: 451, figs 4– 6 [and synonymy therein].— Lemaitre & McLaughlin, 2003: 482.— Coelho et al., 2007: 10.— McLaughlin et al., 2010: 35.— Nucci & Melo, 2011: 37 , figs 1M, 2M, 3M.

New material. Curaçao. Curasub 12–09, 306 m, 24 May 2012: 1 male 6.3 mm, 1 ov female 5.8 mm, CURI 12030, CURI 12031 ( USNM 1253259), 1 female 5.1 mm ( USNM 1253260); Curasub 12–12, 290 m, 7 Aug 2012: 1 male 6.0 mm, CURI 12107 ( USNM 1253261), 1 male 3.7 mm CURI 12136 ( USNM 1253262); Curasub 12–13, 286 m, 8 Aug 2012: 1 female 5.7 mm, CURI 12143 ( USNM 1253263); Curasub 12–14, 123– 256 m, 9 Aug 2012: 1 female 5.1 mm, ( USNM 1253264).

Brazil. TAAF MD55, 63 CB 104, 23°42’S, 42°07’W, 430 m, 1 Jun 1987: 3 females 1.8–2.1 mm, ( MZUSP 16828); Bacia de Campos, Bloco BM–S–4, Belmonte 3, sta 4, 18°48’19.50”S, 032°18’05.37”W, 320 m, Vinicius Padula, 30 Nov 2009: 8 males 1.3–5.8 mm ( MZUSP 23514).

Diagnosis. See McLaughlin & Lemaitre (2001), and Nucci & Melo (2011).

Distribution. Western Atlantic: southeastern coast of United States (North Carolina to Florida), Gulf of Mexico, Caribbean Sea, to Santa Catarina, Brazil. Depth: 11 to 1020 m.

Color ( Fig. 1 E). Shield, pleon, and fourth and fifth pereopods light orange. Ocular peduncles white with dark orange band basally. Right cheliped with coloration on dorsal (outer) surface of chela variable: white with dark orange band on dactyl and fixed finger, or white dark orange along midportion of palm from bases of fingers to proximal palm ridge; proximal surface of chela dark orange; merus and carpus white with prominent dark orange patches on dorsal, lateral and mesial surfaces. Left cheliped: chela white with dark orange proximally; merus and carpus white with wide dark orange band. Ambulatory legs (second and third pereopods): dactyl white with light orange proximal portion; propodus white with dark distal orange band; carpus white with distal and proximal dark orange bands.

Remarks. Although Pylopagurus discoidalis has been abundantly reported in the temperate to tropical western Atlantic (McLaughlin & Lemaitre 2001, 2003), its southern limit of distribution was previously known to be near the Equator, off the coast of Amapá, Brazil. The extent of the southernmost limit of this species was only recently discovered by Nucci & Melo (2011), who reported specimens from Amapá to Santa Catarina, Brazil. The materials reported herein from off Rio Janeiro, add more records of this species from its southern limits, and confirms that this species is common along almost the entire Brazilian coast.

The coloration of Pylopagurus discoidalis has been documented almost exclusively based on specimens that have retained color patterns after preservation. Until the present report, no photographs of live specimens of this species were available. The remarkable color photograph included herein ( Fig. 1 E), was taken of three specimens inhabiting scaphopod shells, collected in Curaçao during a Curasub dive and brought to the surface where they were kept alive in aquaria.

Figures

FIGURE 1. A, Coenobita clypeatus (Fabricius, 1787), in gastropod Melongena melongena: dry specimens [not sexed or measured], W. J. Broderip collection (NHM B 2195, NHM B 2196); B, Allodardanus bredini Haig & Provenzano, 1965, female 10.1 mm, in gastropod shell, Curaçao, Curasub 13 – 21 (USNM 1253325); C, Bathynarius anomalus (A. Milne-Edwards & Bouvier, 1893), in gastropod shell, male, 4.0 mm, Curaçao 12 – 11, CURI 12088 (USNM 1253278); D, Paguristes spinipes A. Milne-Edwards, 1880, in gastropod shell: male 4.8 mm, Curaçao, Curasub 12 – 03, CURI 12040 (USNM 1253258); E, Pylopagurus discoidalis (A. Milne-Edwards, 1880), in scaphopod shells: male 6.3 mm (right), 1 female 5.1 mm (center), 1 ov female 5.8 mm (left), Curaçao, Curasub 12 – 09 (right and center specimens: CURI 12030, CURI 12031, USNM 1253259; left specimen USNM 1253260). (Photos: A, H. Taylor, NHM; B – E, B. B. Brown, Curaçao Seaquarium). Scale: 20 mm (A).