Petrolisthes amoenus ( Guérin-Méneville, 1855 ), Guerin-Meneville, 1855

Ferreira, Luciane Augusto De Azevedo & Tavares, Marcos, 2017, A new species of Pachycheles (Crustacea: Anomura: Porcellanidae), with taxonomic remarks on two other porcelain crabs from the remote oceanic archipelago of Trindade and Martin Vaz, South Atlantic Ocean, Zootaxa 4299 (4), pp. 546-560 : 553-556

Petrolisthes amoenus ( Guérin-Méneville, 1855)

( Fig. 5 A–D)

Porcellana amoena Guérin-Méneville 1855 , pl. 2, fig. 2. [type locality Cuba]. Petrolisthes serratus Henderson 1888: 107 , pl. 11, fig. 2. [type locality off Bahia, Brazil]. Petrolisthes galathinus .— Moreira 1920: 132 [not Petrolisthes galathinus (Bosc, 1802) ]. Petrolisthes amoenus . — Schmitt 1935: 185.

Material examined. Puerto Rico: Mayaguez Harbor, Custom House, 18°12’05”N, 67°08’43”W, R/V “ Fish Hawk ”, 29 January 1899, 7 to 11 m: 1 male ( USNM 49234) . Barbados : 13°11’38”N, 59°32’36”W, 22 May 1918: 1 male, 1 female, 1 ovigerous female ( USNM 68663) ; Ibidem , 13°11’38”N, 59°32’36”W, 1918: 2 ovigerous females ( USNM 68664) ; Needham’s Point , 13°04’43”N, 59°36’45”W, from sponges, 18 May 1918, 6 to 8 m: 1 female, 1 ovigerous female ( USNM 57965) ; Ibidem , 13°04’43”N, 59°36’45”W, 18 May 1918: 1 female, 3 ovigerous females ( USNM 57966) ; Ibidem , 13°04’43”N, 59°36’45”W, from sponges, 18 May 1918, 6 to 8 m: 3 males, 1 female ( USNM 68662) . Curaçao: 12°10’10”N, 68°59’24”W, C van der Horst coll.: 1 female, 1 ovigerous female ( USNM 57539) . Brazil: Ceará, Acaraú, R /V “ Almirante Saldanha ”, st. 1710a, 27 October 1967, 31 m: 1 male ( MZUSP 8948) ; Ibidem, Parque Marinho , associated with sponges, LE Bezerra coll., 15 July 2004: 2 males, 1 ovigerous female ( MZUSP 32713) ; Paraíba, Proj. Algas, st. 69b: 4 males, 1 female ( MZUSP 11854) ; Ibidem, st. 86b, 0 4 June 1981: 2 males (MZUSP 11839); Pernambuco, Fernando de Noronha , March 1998: 1 male ( MZUSP 20250) ; Ibidem, Sancho Bay , RL Moura coll., 0 6 July 1997: 1 male ( MZUSP 32980) ; Bahia, Baía de Todos os Santos, Porto da Barra , 13°00’05”S, 38°32’01”W, C Menegola and L Martins coll., 20 November 2012, 4– 6 m: 1 male, 1 ovigerous female ( MZUSP 29176) ; Ibidem, Porto Seguro, Praia de Mutá , PS Santos coll., 20 March 2011: 1 male, 1 ovigerous female ( MOUFPE 15703) ; Ibidem , PS Santos coll., 25 September 2011, 1 male, 1 ovigerous female ( MOUFPE 15702) ; Espírito Santo, Trindade Island, Ponta Norte , 20°29’18.7’S, 29°20’18.3”W, JB Mendonça coll., 23 October 2014, 14 m: 1 female ( MZUSP 34634) ; Ibidem , 0 2 July 2015, 14.2 m: 14 males, 14 females, 1 ovigerous female, 3 juveniles ( MZUSP 34718) ; Crista do Galo , 20°29’14.8’S, 29°20’13.9”W, JB Mendonça coll., 21 May 2014, 15 m: 1 male ( MZUSP 34647) ; Ponta do Monumento , 20°30’10.3’S, 29°20’36.1”W, JB Mendonça coll., 0 2 September 2014, 15 m: 1 male ( MZUSP 34722) ; Laje da Ponta Noroeste, SCUBA, 20°29’57.8’S, 29°20’39.2”W, JB Mendonça coll., 0 9 July 2012, 17.7 m: 1 ovigerous female ( MZUSP 34691) ; Ibidem , 16 July 2012, 15.3 m: 3 males, 1 ovigerous female ( MZUSP 34646) ; Ilha da Racha, 20°30’26.5’S, 29°20’48.0”W, JB Mendonça coll., 22 June 2012, 27.1 m: 1 male, 1 ovigerous female ( MZUSP 34686) ; Ibidem, 0 3 July 2012, 23 m: 5 males, 1 female (MZUSP 34675); Ibidem , 12 July 2012, 30.3 m: 1 female ( MZUSP 34687) ; Ibidem , 13 July 2012, 23.8 m: 1 female, 1 ovigerous female ( MZUSP 34724) ; Ponta da Calheta, 20°30’18.72’S, 29°18’31.6”W, JB Mendonça coll., 30 April 2014, 15.6 m: 2 females ( MZUSP 34667) ; Ibidem , 0 8 May 2014, 16.6 m: 1 male, 1 ovigerous female ( MZUSP 34632) ; Ibidem , 20 May 2014, 16.3 m: 4 males, 5 females ( MZUSP 34643) ; Ibidem, 20 October 2014, 17 m: 1 male (MZUSP 34701); Ibidem, 11 November 2014, 16 m: 5 males, 2 ovigerous females (MZUSP 34758); Ibiden, 1 male (MZUSP 34744); Ibidem , 25 June 2015, 16.9 m: 2 males, 1 female ( MZUSP 34642) ; Ibidem, 7 males, 14 females (MZUSP 34650); 0 3 August 2015, 17.7 m: 1 ovigerous female (MZUSP 34633); Orelhas, middle of harbor, 20°29’32.3’S, 29°20’32.6”W, JB Mendonça coll., 0 5 May 2014, 14.7 m: 1 female ( MZUSP 34721) ; Ibiden, 20°29’40.2’S, 29°20’32.9”W, JB Mendonça coll., 15 June 2012, 9.7 m: 1 male, 1 ovigerous female ( MZUSP 34669) ; Ibidem, 0 6 July 2013, 14 m: 3 males, 2 females, 1 ovigerous female (MZUSP 34705); Ibidem, 0 1 November 2014, 12 m: 1 female (MZUSP 34703); Ibidem, 1 male, 1 ovigerous female (MZUSP 34789); Ibidem, 1 female (MZUSP 34704); Ibidem , 0 2 July 2015, 14.7 m: 1 male, 1 female ( MZUSP 34631) ; Ibidem , 23 July 2015, 14.6 m: 2 males, 1 ovigerous female ( MZUSP 34671) ; Ibidem, 20°29’40.2’S, 29°20’32.9”W, JB Mendonça coll., 0 1 August 2015, 8.9 m: 1 male ( MZUSP 34676) ; Ibidem , 13 July 2015, 16.1 m: 1 male, 2 females ( MZUSP 34678) ; Praia das Cabritas, 20°29’41.38’S, 29°19’39.99”W, JB Mendonça coll., 25 June 2015, 12 m: 4 males, 3 females (MZUSP 34672); Enseada do Lixo, SCUBA, 20°31’33.9’S, 29°19’33.6”W, JB Mendonça coll., 24 June 2012, 23.5 m: 3 males, 2 ovigerous female ( MZUSP 34685) ; Praia do Lixo (left wall), 20°31’29.8’S, 29°19’43.9”W, JB Mendonça coll., 0 4 November 2014, 15.4 m: 1 ovigerous female ( MZUSP 34688) ; Ibidem, 1 male (MZUSP 34696); Ibidem, 1 male (MZUSP 34694); Praia das Tartarugas, Parcel, 20°31’01.3’S, 29°17’56.9”W, JB Mendonça coll., 30 April 2014, 9.8 m: 1 female ( MZUSP 34639) ; Ibidem, 1 male (MZUSP 34629); Ibidem , 26 June 2012, 9.5 m: 1 male ( MZUSP 34707) ; Enseada dos Portugueses, SECON, 20°30’20.9’S, 29°18’43.7”W, JB Mendonça coll., 12 May 2014, 9 m: 8 males, 2 females, 2 ovigerous females (MZUSP 34679); Ibidem, 1 female (MZUSP 34684); Ibidem , 29 April 2014, 9.9 m: 1 female ( MZUSP 34692) ; Ibidem, 1 female (MZUSP 34699); Farol, 20°29’52.3’S, 29°19’15.6”W, JB Mendonça coll., 0 8 April 2014, 12.9 m: 2 males, 1 female ( MZUSP 34673) ; Ibidem, 1 male (MZUSP 34690); Ibidem, 1 male (MZUSP 34695); Ibidem , 17 April 2014, 12.9 m: 2 males, 2 females ( MZUSP 34668) ; Ibidem , 17 April 2014, 13.3 m: 1 male ( MZUSP 34635) ; Ibidem , 0 8 May 2014, 13.2 m: 9 males, 6 females, 2 ovigerous females ( MZUSP 34636) ; Ibidem , 20 May 2014, 13.1 m: 1 female ( MZUSP 34706) ; Ibidem , 0 6 July 2015, 12.6 m: 1 male, 1 female, 1 ovigerous female ( MZUSP 34641) ; Ibidem, 29 males, 16 females, 2 ovigerous females, 1 juvenile (MZUSP 34702); Ibidem , 22 April 2014, on seaweeds, 13.7 m: 16 males, 9 females ( MZUSP 34681) ; Ibidem , 0 6 July 2015, 12.6 m: 1 ovigerous female ( MZUSP 34670) ; Praia dos Portugueses, Rampa Nova , 20°30’17.7’S, 29°18’56.7”W, JB Mendonça coll., 11 July 2012, 11 m: 2 males, 1 ovigerous female ( MZUSP 34720) ; Ibidem , 18 April 2014, 10.2 m: 4 males, 4 females, 2 ovigerous females ( MZUSP 34680) ; Ibidem , JB Mendonça coll., 23 April 2014, 10.7 m: 1 male, 2 females, 1 ovigerous female ( MZUSP 34674) ; Ibidem: 1 male, 1 female (MZUSP 34682); Ponta da Cachoeira, 20°30’31.1’S, 29°20’39.5”W, JB Mendonça coll., 21 July 2015, 19.1 m: 1 male ( MZUSP 34689) ; Enseada da Cachoeira, 20°30’57.1’S, 29°20’15.2”W, JB Mendonça coll., 0 9 July 2012, 13.8 m: 1 male ( MZUSP 34700) ; Farrilhões, 20°31’22.4’S, 29°19’52.0”W, JB Mendonça coll., 16 June 2012, 11.9 m: 1 male, 1 female ( MZUSP 34698) ; Ibidem , 20 June 2012, 11.8 m: 8 males, 1 female, 4 ovigerous females ( MZUSP 34719) ; Ibidem , 0 4 July 2012, 17.9 m: 3 males, 2 females, 1 ovigerous female ( MZUSP 34697) ; Ibidem, 20°30’18.72’S, 29°18’31.6”W, JB Mendonça coll., 0 8 July 2013, 9.5 m: 1 male ( MZUSP 34630) ; Ibidem, 1 male, 3 ovigerous females (MZUSP 34693); Ibidem , 0 4 April 2014, 12.2 m: 1 male, 1 ovigerous female ( MZUSP 34677) ; Ibidem: 1 female (MZUSP 34638); Ibidem , 20°31’29.8’S, 29°19’52”W, 22 July 2015, 22.6 m: 1 male ( MZUSP 34637) ; Ibidem, 23 July 2015, 17 m: 1 male, 1 ovigerous female (MZUSP 34649); Enseada do Príncipe, Paredão, 20°31’36.9’S, 29°18’14.3”W, JB Mendonça coll., 0 1 August 2015, 17.4 m: 1 male ( MZUSP 34645) ; Laje da Praia do Príncipe, 20°31’24.3’S, 29°18’46.5”W, JB Mendonça coll., 23 April 2014, 14.4 m: 3 males ( MZUSP 34723) ; Ilha Sul, 20°31’34.3’S, 29°19’27.9”W, JB Mendonça coll., 10 July 2015, 22.2 m: 1 male, 1 female, 2 juveniles ( MZUSP 34640) ; Martin Vaz Archipelago, Martin Vaz Island, 20°28’28.42’S, 28°51’24.56”W, JB Mendonça coll., 21 June 2015, 21.4 m: 1 female ( MZUSP 34666) ; 20°30’45.7’S, 29°18’21.9”W, JB Mendonça coll., 24 July 2013, 12.3 m: 1 male ( MZUSP 34644) ; Espírito Santo, Piúma , 20°50’578”S, 40°28’253” W, A Jório coll., 28 March 2010, 21.5 m: 1 male ( MZUSP 24568) ; Ibidem , A. Jório coll., July 2005: 1 male ( MZUSP 19503) ; Ibidem , east side, 20°51’281”S, 40°29’513” W, SJ Silva and HM Filho coll., 14 May 2011: 1 male ( MZUSP 24546) ; Ibidem , REVIZEE, st. VV33, 18°53’26”S, 39°13’84”W, 28 February 1996, 37 m: 1 male ( MZUSP 19509) ; Rio de Janeiro, Ipanema , PS Young coll., 0 1 April 1993: 1 male, 2 juveniles ( MZUSP 31066) ; São Paulo, Proj. Vitória, Ilhota das Cabras , Cobo and Alves coll., June 2004: 1 male, 1 ovigerous female ( MZUSP 16713) .

Size. Largest male, cl 9.5, cw 9.2 ( MZUSP 34744). Largest female, cl 8.6, cw 8.3 ( MZUSP 34789). Smallest ovigerous female, cl 5.5, cw 5.2 ( MZUSP 34758).

Coloration. In Petrolisthes amoenus ( Fig. 5 A) color patterns vary strongly with size. Small specimens (cl 3.9, cw 3.5) presents brownish to orange dots over a dominant white background; small dots cluster together forming larger dots or slender stripes on the carapace and chelipeds. On P2–5 there is a reticulate pattern of brownish to orange thick stripes. In larger specimens (cl 5.7, cw 5.3) the carapace is regularly and densely covered by a reticulate pattern of slender, carmine red stripes over a much more discrete white background. The cheliped carpus, merus and proximal half of propodus have carmine red stripes variable in size and thickness over a dominant white background, while the distal half of the propodus, fixed finger and dactylus are carmine red. On P2–5 the reticulate pattern of thick stripes is carmine red in color ( Fig. 5 B). Full grown specimens (cl 9.4, cw 8.5) are mostly reddish to dark orangish on carapace and chelipeds; the reticulate pattern on P2–5 is carmine red crossed by 3 or 4 transversal white stripes intercalated with the remaining red. A large carmine red spot over a light orangish background is well characteristic on the Mxp 3 merus ( Fig. 5 C). The ventral surface of the body is also distinctly reddish with small light yellowish areas ( Fig. 5 C).

Habitat. Petrolisthes amoenus has been reported to live on corals, calcareous algae, sponges and under rocks, from shallow waters down to depths of 140 m ( Veloso & Melo 1993; Poupin & Lemaitre 2014; Ferreira & Melo 2016). In Trindade and Martin Vaz Islands P. amoenus was frequently found along with P. meloi sp. nov. in association with calcareous algae; 8–30 m depth.

Distribution. Western Atlantic—United States, Florida; Mexico, Yucatán; Cuba; Puerto Rico; Barbados; Lesser Antilles; Trinidad and Tobago; Colombia, Providencia and Santa Marta Islands; Venezuela, Los Roques, Cubagua and Gran Roque Islands; and Brazil (continental shelf between Maranhão and São Paulo, and oceanic islands of Fernando de Noronha, and Trindade and Martin Vaz).

Remarks. Some degree of morphological variation is observable in Petrolisthes amoenus , some of which related to the size of the specimens: (1) presence of dense, short, robust setae on the dorsal surface of the carapace mainly in small specimens (such setae are usually absent in larger specimens and absent in full grown specimens); and (2) the degree of development of the outer orbital angle, which can be furnished with a spine variable in size (or even show as only a slight bump) in large specimens (outer orbital angle provided with a conspicuous spine in small specimens). However, some morphological variations are observable in specimens of same size and sex: (1) antennular basal segment with 4 to 6 distal spines (usually 4); (2) 4 or 5 spines on the mesial margin of P1 carpus; and (3) a fringe of setae on the lateral margin of the P1 propodus either slightly evident and present only on its proximal half or quite evident along the entire lateral margin of the P1 propodus.

Moreira (1920) recorded Petrolisthes galathinus (Bosc, 1802) from Trindade Island based on two specimens (cl 7 mm, cw 6 mm and 11 mm, cw 10 mm, respectively) no longer available in the collections of the Museu Nacional, Rio de Janeiro. However, no specimens of P. galathinus were recovered from Trindade since them. It is not uncommon to find specimens of P. amoenus misidentified with P. galathinus in museum's collections and it may well be that the specimens from Trindade assigned by Moreira to P. galathinus actually belong to P. amoenus .

Figures

FIGURE 5. (A – D) Petrolisthes amoenus (Guérin-Méneville, 1855). (E – F) Petrolisthes marginatus Stimpson, 1859. (A) Female, cl 3.9, cw 3.5, dorsal view (MZUSP 34703). (B) Ovigerous female, 5.7 cl, 5.3 cw, dorsal view (MZUSP 34688). (C – D) Male, cl 9.4, cw 8.5, dorsal and ventral views, respectively (MZUSP 34753). Note in A – C color pattern varying strikingly with size. (E-F) Female, cl 8.4, cw 8.6, dorsal and ventral views, respectively (MZUSP 34648). Scale bars = 5 mm.