Amphithrax aculeatus (Herbst, 1790)

Parasram, Nadeshinie, Santana, William & Vallès, Henri, 2023, Checklist of the shallow-water marine Brachyura (Crustacea: Decapoda) of Barbados, West Indies, Zootaxa 5314 (1), pp. 1-62 : 20

Amphithrax aculeatus (Herbst, 1790)

( Fig. 9B )

Cancer aculeatus Herbst, 1790: 248 , pl. 18, fig. B, pl. 19, fig. 104 [type-locality: Americas; type in Berlin Museum].

Mithrax aculeatus . — Schomburgk 1848: 65; Stimpson 1860: 188; Desbonne in Desbonne & Schramm 1867: 5; A. Milne-Edwards 1880: 102.

Mithrax pilosus Rathbun, 1892: 262 , pl. 39; 1901: 66; 1921: 83; 1933: 29; Nutting 1919: 75; Rodriguez 1980: 287; Wagner 1990: 25–29, figs. 28–31; Lira et al. 2013: 55, tab. 1.

Amphithrax aculeatus . — Assugeni et al. 2017: 1630, tab. 1; Poupin 2018: 192–193, fig. 210; Mantelatto et al. 2020: 39 .

Distribution. Western Atlantic: USA (South Carolina to Florida), Bahamas, Cuba, Puerto Rico, Gulf of Mexico, St. Thomas, St. Martin, St. Barthélemy, Antigua, Guadeloupe, Martinique, Barbados, Isla de Margarita, Tortuga, Los Roques, Curaçao, Aruba, Venezuela, and Brazil. ( Rathbun 1901; Carmona-Suárez & Poupin 2016; Poupin 2018; Mantelatto et al. 2020).

Material examined. Barbados, Drill Hall , St. Michael, nearshore rubble, 13°04’36.30” N, 59°36’26.63” W, 1 ♀, 2 Ô CW: 29.2, 22.2, 24.6 mm ( BLSZ 120 ) . Idem , 3 Ô, CW: 12.4, 12.5, 7.8 mm ( BLSZ 129 ) . Idem , 1 ♀ (juv.) CW: 53.8 mm ( BLSZ 217 ) . Jordans, St. James , nearshore rubble, 13°14’48.24”N, 59°38’40.90”W, 2 Ô, 1 ♀ CW: 10.6, 30.5, 40.5 mm ( MZUSP 40878 , 40884 ) .

Remarks. This species is very abundant in nearshore rubble habitat on the west coast of Barbados and can be easily collected by hand at low tide under rock rubble. A. aculeatus was collected under the same rubble rock as Amphithrax verrucosus (H. Milne Edwards, 1832) , Mithraculus coryphe (Herbst, 1801) , Mithraculus forceps A. Milne-Edwards, 1875 , Eriphia gonagra , and Pachygrapsus transversus ( Gibbes, 1850) . First reported for Barbados by Schomburgk (1848: 655) as Mithrax aculeatus , these specimens are stored at the NHM. Rathbun (1921: 83) reported one male specimen of Mithrax pilosus that was collected by the Barbados-Antigua Expedition in 1918 as a first record for Barbados (USNM 1519303); however, this species was previously reported by Schomburgk (1848: 65). Jones (1969: 380) also reported M. pilosus for Barbados. The taxonomy of this species has undergone numerous revisions. Ng et al. (2008: 123) considers Mithrax pilosus as a junior synonym of Mithrax aculeatus ; however, M. pilosus is recognised as a valid species by Felder et al. (2009: 1077) and Carmona-Suárez & Poupin (2016: 373, fig. 6H). Given this, we follow Ng et al. (2008: 120) and maintain M. pilosus as a junior synonym of A. aculeatus . Also, Windsor & Felder (2014: 155, fig. 3G) considers Mithrax verrucosus H. Milne Edwards, 1832 , as a junior synonym of Mithrax aculeatus Herbst, 1790 and later, Windsor & Felder (2017) corrected some points presented in Windsor & Felder (2014) regarding the taxonomy of Mithrax Latreille, 1816 and established the genus Amphithrax Windsor & Felder, 2017 to accommodate several species previously included in Mithrax . We do not follow the synonym between Amphithrax aculeatus and Amphithrax verrucosus ; instead, we follow the opinions of Ng et al. (2008: 123), Carmona-Suárez & Poupin (2016: 372, figs. 87A, B) and Poupin (2018: 192–193; figs. 210, 211) recognising Amphithrax aculeatus and Amphithrax verrucosus as different species based on several morphological differences observed. Amphithrax aculeatus can be easily identified by the presence of spines on the upper margin of the palm of the chelipeds and by the presence of two to three spines on the propodus of ambulatory legs (modified from Wagner 1990).

Figures

FIGURE 9. Superfamily Majoidea Samouelle, 1819, dorsal habitus:A, Stenorhynchus seticornis (Herbst, 1788), female (ovig.), cw 9.1 mm (BLSZ 135); B, Amphithrax aculeatus (Herbst, 1790), male, cw 41.6 mm (BLSZ 214); C, Amphithrax hemphilli (Rathbun, 1892), male, cw 4.5 mm (BLSZ 043); D, Amphithrax verrucosus (H. Milne Edwards, 1832), male, cw 41.6 mm (BLSZ 218). Scale bars: A, B, D = 20 mm; C = 5 mm.