Mithraculus forceps A. Milne-Edwards, 1875: 109 Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean TAVARES, MARCOS MENDONÇA, JOEL BRAGA DE JR. Zootaxa 2022 2022-06-02 5146 1 1 129 73LCV 504428 A. Milne-Edwards, 1875 A. Milne-Edwards 1875 [151,709,330,357] Malacostraca Mithracidae Mithraculus Animalia Decapoda 39 40 Arthropoda species forceps  ( Fig. 21A–D)    Mithraculus forcepsA. Milne-Edwards, 1875: 109, pl. 23, fig. 1 [ Typelocality: Cayenne, French Guiana].   Trindade and Martin Vaz specimens.  1 male( MZUSP 33739), Trindade Island, Enseada das Orelhas, 20°29’40.2”S, 29°20’32.9”W, J.B. Mendonçacoll.,  01.xi.2014,  12 m. 1 male, 1 female( MZUSP 39840), ibidem,  2.vii.2015,  14.7 m. 1 ovigerous female ( MZUSP 39681), ibidem,  1.vii.2016,  9.2 m.  1 male( MZUSP 39853), ibidem, Ponta da Calheta, 20°30’18.72”S, 29°18’31.67”W, J.B. Mendonçacoll.,  20.x.2014,   17 m.  1 male, 1 female, 2 ovigerous female, 1 ju venile female ( MZUSP 40741), ibidem, 20°30’19.5”S, 29°18’47.3”W, J.B. Mendonçacoll.,  26.vi.2012,  14.3 m. 1 ovigerous female ( MZUSP 40602),  1 juvenilefemale ( MZUSP 40245), ibidem,  24.xi.2017,  17 m . 1 male, 3 ovigerous females ( MZUSP 39911), ibidem, 20°30’18.72”S, 29°18’31.6”W, J.B. Mendonçacoll.,  29.iv.2014, 15,  9 m . 1 ovigerous female ( MZUSP 40568), ibidem,  24.vi.2017,  19.3 m.  1 male( MZUSP 39682), ibidem, 20°30’29.5”S, 29°18’37.0”W, J.B. Mendonçacoll.,  20.vi.2016,  8.2 m.  3 males, 6 ovigerous females ( MZUSP 40586), ibidem, 20°30’16.59”S, 29°18’30.11”W, J.B. Mendonçacoll.,  30.i.2019,  15.1 m.  1 male, 1 juvenilefemale ( MZUSP 33738),  1 juvenilefemale ( MZUSP 40759),  1 male, 3 females( MZUSP 41131), ibidem, Enseada dos Portugueses, Farol, 20°29’52.3”S, 29°19’15.6”W, J.B. Mendonçacoll.,  8.iv.2014,  12.9 m.  3 males, 3 juvenilemales, 1 juvenile( MZUSP 41132),  22.iv.2014,  13.7 m.  2 males, 4 ovigerous females ( MZUSP 39637), ibidem,  25.vii.2018,  10 m . 1 male ( MZUSP 40187), ibidem,  25.vii.2018,  10 m . 1 female ( MZUSP 39859), ibidem, Enseadados Portugueses, 20°30’17.7”S, 29°18’56.7”W, J.B. Mendonçacoll.,  18.iv.2014,  10.2 m.  1 male, 1 juvenilemale, 1 juvenile( MZUSP 40703), ibidem, 20°30’20.9”S, 29°18’43.7”W, J.B. Mendonçacoll.,  29.iv.2014,  9.9 m. 1 ovigerous female ( MZUSP 40561), ibidem, Ponta Norte, 20°29’18.7”S, 29°20’18.3”W, J.B. Mendonçacoll.,  31.vii.2018,  12.4 m.  1 male, 2 females( MZUSP 39919), ibidem,  2.vii.2015.  2 males, 1 maleand 1 femalejuveniles ( MZUSP 39827), ibidem, Ponta do Monumento, 20°30’10.3”S, 29°20’36.1”W, J.B. Mendonçacoll.,  3.vii. 2015,  15.5 m.  1 male, 3 juvenilemales, 1 ovigerous female, 2 juvenilefemales ( MZUSP 39619), ibidem, Ilha da Racha, 20°30’26.5”S, 29°20’48.0”W, J.B. Mendonçacoll.,  30.vii. 2018,  24.8 m.  3 males, 1 juvenilemale, 1 female( MZUSP 39883), ibidem, Praia das Cabritas, 20°29’41.38”S, 29°19’39.99”W, J.B. Mendonçacoll.,  25.vi. 2015,  12 m . 1 damaged male ( MZUSP 39847),  1 juvenilemale ( MZUSP 40669), Martin Vaz, Ilhote Principal, 20°28’26.98”S, 28°51’20.98”W, coralligenous sediment, C.H. Guimarãescoll.,  22.i.2012,  19.2 m. Size of largest male: cl 15 mm, cw 17.5 mm; largest female: cl 12.9 mm, cw 14.9 mm.  Comparative material examined.  Mithraculus forceps:  United States: 2 males, 2 females( USNM 16046), Florida, Indian Key, along shore, low tide, no further details. Caribbean Sea: Grenada: 1 male( MZUSP 28066), Grand Anse Bay, 12°1’45.68”S, 61°46’18.67”W, L.R.L. Simone et al.coll.,  8.x.2012,  10 m.  Brazil: Central Atlantic: 3 males( MZUSP 41237), São Pedroand São Paulo Archipelago, Cabea da Tartaruga, W. Santana et al.coll.,  18.ii.2009to  5.iii.2009.  Rocas Atoll: 1 juvenilemale, 1 female( MZUSP 12476), R.L. Mouraand R.S. Rosacoll.  Paraíba: 3 males, 2 females( MZUSP 11804), Projeto Algas, stn 69-b, 6°46’S, 34°47’W,  19.v.1981,  18 m. 1 male ( MZUSP 15524), João Pessoa,  Ponta do Cabo Branco, M.F.C. Lima coll.,  21.iii.2000.  Fernando de Noronha Archipelago: 1 juvenilemale ( MZUSP 20561), 3°50’11”S, 32°23’53.4”W, L.R. Simoneand C.M. Cunha coll.,  8.iii.2009.  2 males( MZUSP 20540), ibidem, Praia do Porto, 3°50’S, 32°24’01.6”W, L.R. Simoneand C.M. Cunhacoll.,  10.iii.2009.  1 juvenilemale ( MZUSP 34303), ibidem, Buraco da Raquel, next to the Port, L.R.L. Simonecoll.,  4.v.2013.  Pernambuco: 1 male( MZUSP 32455), Tamandar,  Praia de Tamandar, R.Silva coll.,  i.1990.  Bahia: 7 males, 11 ovigerous females ( MZUSP 41233), Minerva Bank, 17°03.108’S, 37°37.216’W, J. Coltrocoll.,  12.viii.2012,  69 m.  Rio de Janeiro: 1 male, 1 female( MZUSP 20322), Búzios, Praia dos Ossos. 1 juvenilemale, 6 ovigerous females, 1 juvenilefemale ( MZUSP 21339), Maricá, Ilhas Maricás, M. Tavarescoll.,  21.iv.1985, on  Schizoporella.  2 males, 2 juvenilefemales, 5 juveniles( MZUSP 2826), Angra dos Reis, Praia de Vila Velha, G.A.S. Melocoll.,  14.vii.1966. 3 males, 2 juvenile males, 3 ovigerous females, 3 juvenile females (MZUSP 3662), Ilha Grande, Praia do Furado, G.A.S. Melo coll. 20.vii.1966.   Distribution.From North Carolina, through Gulf of Mexico, Caribbean Sea, north coast of South America to Brazil( Maranhãoto Santa Catarina) ( Melo 1996; Serejo et al.2006; Bouzon & Freire 2007; Felder et al.2009). Brazilian oceanic islands: known from São Pedro and São Paulo, Rocas Atoll, Fernando de Noronha and Trindade and Martin Vaz.  Mithraculuscf. forcepshas been reported from the late Pleistocene of Jamaica( Klompmaker et al.2015, and references therein).   FIGURE 21.A–D,  Mithraculus forcepsA. Milne-Edwards, 1875. A, Male MZUSP 33739, cl 11.8 mm, cw 13.5 mm. B, Ovigerous female (MZUSP 40602), cl 11.9 mm, cw 13.4 mm. C, Ovigerous female (MZUSP 40568), cl 8.5 mm, cw 9.5 mm. D, Juvenile female (MZUSP 40245), cl 5.8 mm, cw 6.2 mm. Habitus, dorsal (A, C, D) and ventral (B) view. Photographs by A. Pol.  Ecological notes.  Mithraculus forcepsis commonly associated with different substrata, including the sponges  Amphimedon viridisDuchassaing & Michelottiand  Stematumenia strobilinia(Lamarck), the calcareous bryozoans  Schizoporella unicornis(Johnston in Wood) and  S. errata(Waters),  Poritesspp.corals, sand reefs of  Phragmatopoma caudataKrøyer, mangroves (Caribbean coast), seagrass (  Thalassia) and macroalgae, and also has been found under stones and in coralligenous sediment, from the tide mark down to 100 m( Rodríguez 1980; Gore et al.1981; Williams 1984; Melo 1996; Rieger & Giraldi 1996; Mantelatto & Souza-Carey 1998; Morgado & Tanaka 2001; Cobo 2002; Alves et al.2012b, 2012 c, 2013; Lane-Medeiros et al.2021).  Mithraculus forcepsis very common in Trindade (seemingly less so in Martin Vaz), where it has been found between 8 and 24 m. It also has been reported to be the commonest crab species in insular coastal habitats ( Alves et al.2012b).  Mithraculus forcepsis a prey for Octopus insularisjuveniles in the Rocas Atoll ( Bouth et al.2011). The average size of adult females has been estimated in 11.2 mm ± 1.5 mm. The females attain morphological sexual maturity at a larger sizes than males at around 12.9 mm( Cobo 2002, 2006; Cobo & Alves 2009). Females can use stored sperm to fertilize eggs for more than one consecutive spawn without mating ( Penha-Lopes et al.2006). Ovigerous females have been reported all year-round, which translates into constant larval supply. The mean larval duration from hatching to crab I is of about 8.3 ± 0.5 days; the duration for the zoea I and II stages is of about 2 days each, and 3–8 days for the megalopa in laboratory conditions ( Rhyne et al.2005). Larval duration may be longer (over 14 days) depending on the rearing conditions ( Wilson et al.1979).  Mithraculus forcepsis said to have facultative lecithotroph larvae, which can also ingest prey when available. It also has been found that late megalopa starvation has no significant influence on the survival to juvenile or larval duration and that temperature is the most important factor regulating survival and growth of larvae and juveniles in laboratory conditions ( Figueiredo et al.2008). However, observations by W. Santana (pers. com.) stand in contradiction to the results derived by Figueiredo’s et al.(2008)observations, as all non feeded larval stages of  M. forcepsreared in laboratory conditions by Santana tended to die faster and in more quantity than the fed larvae. If the facultative lecithotrophic development is confirmed for  M. forceps, it might help to explain (along with constant larval supply) the ability of the widely distributed  M. forcepsto colonize new areas offshore.  Mithrax forcepsis a popular species in the aquarium trade and may come under pressure from the pet trade in the future ( Penha-Lopes et al. 2006; Figueiredo et al. 2008).   Remarks.  Mithraculus forcepscan co-occur with  Teleophrys pocockiand very small juveniles of the two species can be mistaken for each other at a first glance. However, those of  M. forcepscan be easily recognized by having the carapace more flattened and grooved and the cheliped carpus with acute spines — cheliped carpus with only a tubercle of variable size near the inner anterolateral angle in aged specimens ( Fig. 21A–D) (vs carapace markedly swollen, particularly at the branchial, cardiac and intestinal regions, and cheliped carpus devoid of acute spines in  T. pococki) ( Fig. 24A–G). The carapace becomes distinctly wider than long with growth in males and females of  M. forceps. The pereopods P2–P5 have many stiff setae and are spiny in developing specimens (denticulate in aged ones), which favor the adherence of fouling organisms ( Fig. 21A–D). The ejaculatory canal aperture of the first gonopod is not fully formed until the males attain 8.8 m(cw) ( Mollemberg et al.2021). The carapace and chelipeds are glabrous and practically never have fouling organisms adhered to it ( Fig. 21A, C). In the specimens from the São Pedro and São PauloArchipelago the dorsal surface of the carapace looks more polished and the carapace grooves more faint.  A. Milne-Edwards(1875: pl. 23, fig. 1) depicted the holotypemale (cw 35 mm) of  M. forcepsand stated that it was from Cayenne. Therefore, its type locality can be narrowed down to Cayenne, French Guiana. 4985387405 2014-11-01 MZUSP Enseada das Orelhas & J. B. Mendonca 12 -20.494501 Trindade Island 1 -29.342472 39 40 MZUSP 33739 1 1 1 4985387426 2014-11-01 MZUSP Enseada das Orelhas & J. B. Mendonca 12 -20.494501 Trindade Island 1 -29.342472 39 40 MZUSP 33739 1 1 1 4028571654 [186,883,577,604] 2016-07-01 MZUSP 9 39 40 MZUSP 39681 1 4028571557 2014-10-20 MZUSP J. B. Mendonca -20.5052 Ponta da Calheta 1 -29.308796 39 40 MZUSP 39853 1 1 4985387430 [922,986,613,640] 2012-06-26 MZUSP J. B. Mendonca 17 -20.505417 1 -29.313139 39 40 MZUSP 40741 18 1 17 4985387318 2012-06-26 MZUSP J. B. Mendonca 17 -20.505417 1 -29.313139 39 40 MZUSP 40741 18 1 17 4028571365 MZUSP 39 40 MZUSP 40602 1 4028571927 [552,1236,685,712] 2017-11-24 MZUSP 17 39 40 MZUSP 40245 1 1 4028571531 2014-04-29 MZUSP J. B. Mendonca 9 -20.5052 1 -29.308777 39 40 MZUSP 39911 1 4028571653 2017-06-24 MZUSP 19 39 40 MZUSP 40568 1 4028571870 2016-06-20 MZUSP J. B. Mendonca 8 -20.508194 1 -29.310278 39 40 MZUSP 39682 1 1 4028571626 2019-01-30 MZUSP J. B. Mendonca 15 -20.504608 1 -29.308363 39 40 MZUSP 40586 3 3 4028571512 MZUSP 39 40 MZUSP 33738 2 1 1 4028571472 [245,638,865,892] MZUSP 39 40 MZUSP 40759 1 1 4028571473 2014-04-08 MZUSP Enseada dos Portugueses & J. B. Mendonca 13 -20.497862 Farol 1 -29.321001 39 40 MZUSP 41131 4 3 1 4985387390 2014-04-22 MZUSP 14 39 40 MZUSP 41132 1 1 4028571952 [586,1432,937,964] 2018-07-25 MZUSP 10 39 40 MZUSP 39637 2 2 4028571946 2018-07-25 MZUSP 10 39 40 MZUSP 40187 1 4028571478 2014-04-18 MZUSP J. B. Mendonca 10 -20.504917 Enseada 1 -29.31575 Portugueses 39 40 MZUSP 39859 1 4985387417 2014-04-29 MZUSP J. B. Mendonca 10 -20.505806 1 -29.312138 39 40 MZUSP 40703 1 1 4028571728 2018-07-31 MZUSP J. B. Mendonca 12 -20.488527 Ponta Norte 1 -29.338417 39 40 MZUSP 40561 1 4028571381 2015-07-02 MZUSP 39 40 MZUSP 39919 3 2 1 4028571559 2015-07-03 MZUSP J. B. Mendonca 16 -20.502861 Ponta do Monumento 1 -29.34336 39 40 MZUSP 39827 4 1 3 4985387340 2018-07-30 MZUSP J. B. Mendonca 25 -20.50736 Ilha da Racha 1 -29.346668 39 40 MZUSP 39619 2 2 4985387361 2015-06-25 MZUSP J. B. Mendonca 12 -20.494827 Praia das Cabritas 1 -29.327776 39 40 MZUSP 39883 1 1 4985387380 [1014,1018,1262,1288] MZUSP 39 40 MZUSP 39847 1 4985387303 [1026,1410,1261,1287] MZUSP 39 40 MZUSP 39847 1 4028571469 2012-01-22 MZUSP C. H. Guimaraes 19 -20.474161 Martin Vaz 1 -28.855827 Ilhote Principal 39 40 MZUSP 40669 1 1 4028571328 USNM Indian Key & Caribbean Sea United States of America Florida 39 40 USNM 16046 4 2 2 4028571425 2012-10-08 MZUSP L. R. L. Simone Grenada 10 -12.029355 Grand Anse Bay 1 -61.771854 39 40 MZUSP 28066 11 1 4028571545 1981-05-19 2009-03-05 1981-05-19 MZUSP W. Santana et al. Brazil Central Atlantic 18 -3.8363888 Archipelago 15 -32.398167 Sao Pedro 39 40 MZUSP 41237, MZUSP 12476, MZUSP 11804, MZUSP 15524, MZUSP 20561 29 3 2 24 Sao Paulo 4028571320 1981-05-19 2009-03-05 1981-05-19 MZUSP R. L. Moura & R. S. Rosa Brazil Central Atlantic 18 -3.8363888 Archipelago 15 -32.398167 Sao Pedro 39 40 MZUSP 41237, MZUSP 12476, MZUSP 11804, MZUSP 15524, MZUSP 20561 29 3 2 24 Sao Paulo 4985387382 [209,1414,1585,1612] 1981-05-19 2009-03-05 1981-05-19 MZUSP M.F.C. Lima Brazil Central Atlantic 18 -3.8363888 Archipelago 15 -32.398167 Sao Pedro 39 40 MZUSP 41237, MZUSP 12476, MZUSP 11804, MZUSP 15524, MZUSP 20561 29 3 2 24 Sao Paulo 4985387378 1981-05-19 2009-03-05 1981-05-19 MZUSP M.F.C. Lima Brazil Central Atlantic 18 -3.8363888 Archipelago 15 -32.398167 Sao Pedro 39 40 MZUSP 41237, MZUSP 12476, MZUSP 11804, MZUSP 15524, MZUSP 20561 29 3 2 24 Sao Paulo 4985387386 1981-05-19 2009-03-05 1981-05-19 MZUSP L.R. Simone & C.M. Cunha Brazil Central Atlantic 18 -3.8363888 Archipelago 15 -32.398167 Sao Pedro 39 40 MZUSP 41237, MZUSP 12476, MZUSP 11804, MZUSP 15524, MZUSP 20561 29 3 2 24 Sao Paulo 4985387421 1981-05-19 2009-03-05 1981-05-19 MZUSP L.R. Simone & C.M. Cunha Brazil Central Atlantic 18 -3.8363888 Archipelago 15 -32.398167 Sao Pedro 39 40 MZUSP 41237, MZUSP 12476, MZUSP 11804, MZUSP 15524, MZUSP 20561 29 3 2 24 Sao Paulo 4985387339 2009-03-08 2013-05-04 1966-07-14 MZUSP L. R. Simone Saint Helena, Ascension and Tristan da Cunha Buraco da Raquel 69 -3.8333333 Praia do Porto 925 -32.400448 Pernambuco 39 40 MZUSP 20540 2 1 10 2 4985387329 [260,1261,1765,1792] 2009-03-08 2013-05-04 1966-07-14 MZUSP L. R. Simone Saint Helena, Ascension and Tristan da Cunha Buraco da Raquel 69 -3.8333333 Praia do Porto 925 -32.400448 Pernambuco 39 40 MZUSP 20540 2 1 10 2 4985387397 2009-03-08 2013-05-04 1966-07-14 MZUSP L. R. Simone Saint Helena, Ascension and Tristan da Cunha Buraco da Raquel 69 -3.8333333 Praia do Porto 925 -32.400448 Pernambuco 39 40 MZUSP 20540 2 1 10 2 4985387356 [186,740,1837,1863] 2009-03-08 2013-05-04 1966-07-14 MZUSP L. R. Simone Saint Helena, Ascension and Tristan da Cunha Buraco da Raquel 69 -3.8333333 Praia do Porto 925 -32.400448 Pernambuco 39 40 MZUSP 20540 2 1 10 2 4985387365 2009-03-08 2013-05-04 1966-07-14 MZUSP L. R. Simone Saint Helena, Ascension and Tristan da Cunha Buraco da Raquel 69 -3.8333333 Praia do Porto 925 -32.400448 Pernambuco 39 40 MZUSP 20540 2 1 10 2 4985387347 2009-03-08 2013-05-04 1966-07-14 MZUSP L. R. Simone Saint Helena, Ascension and Tristan da Cunha Buraco da Raquel 69 -3.8333333 Praia do Porto 925 -32.400448 Pernambuco 39 40 MZUSP 20540 2 1 10 2