Mactrotoma fragilis Gmelin 1791
Creators: name: Signorelli, Javier H.
name: Pastorino, Guido
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Bivalvia
Veneroida
Mactridae
Mactrotoma
Mactrotoma fragilis

description: Mactrotoma fragilis (Gmelin, 1791)
Figures 6 A–K, 7A–E
Mactra fragilis Chemnitz, 1782: 236, pl. 24, fig. 235 (rejected by ICZN, 1944, Opinion 184); Gmelin, 1791: 3261; Spengler 1802: 124; Wood, 1818: 30; Turton, 1822: 74, pl. 4, fig. 10; Conrad, 1831: 61, pl. 14, fig. 3; De Kay, 1843: 230; d’Orbigny, 1846 in 1834–1847: 508; 1853: 222; Forbes & Hanley, 1853: 368; Reeve, 1854: pl. 11, fig.47; Wood & Hanley, 1856: 39, fig. 32; Carpenter, 1855, in Carpenter, 1855 –57: 51; Martinez y Saez, 1869: 12; Mörch, 1870: 124; Weinkauff, 1884: 17, pl. 5, fig. 2; Dall, 1895: 211; 1894: 26; Lamy, 1917: 246; Maury, 1920: 131; Perry, 1940: 82, pl. 17, fig. 113; Abbott, 1954: 488, fig. 5587; Cauquoin, 1967: 223; Rios, 1970: 195; 1975: 236, pl. 75, fig. 1129; 1985: 243, pl. 86, fig. 1210; 1994: 265, pl. 90, fig. 1292, 2009: 535, fig. 1486; Altena, 1971: 52.
Lutraria candida Lamarck, 1818 in 1815–1822: 470; Deshayes & Milne-Edwards, 1835: 92; Hanley, 1842 in 1842 – 1856: 27; Lamy, 1913: 346.
Mactra braziliana Lamarck, 1818 in 1815–1822: 478— Deshayes & Milne-Edwards, 1835: 106; Beau, 1853: 414; Hanley, 1842 in 1842– 1856: 31, pl. 10, fig. 60; Conrad, 1868, 45; Gundlach, 1883b: 482; Dall, 1894b: 26; Lamy, 1914: 243.
Mactra oblonga Say, 1822: 310 — Conrad, 1868, 45; Dall, 1894b: 26.
Mactra oblongata [error pro oblonga] Ravenel, 1834: 2.
Spisula fragilis Gray, 1837: 373; Conrad, 1868: 45.
Mactra bilineata Reeve, 1854: pl. 15, fig. 72— Deshayes, 1855a: 67; Weinkauff, 1884: 84, pl. 28, figs. 6–6a; Tomlin, 1924: 136.
Standella bilineata H. Adams & A. Adams, 1856 in 1853–1858: 382— Dall, 1894b: 26.
Standella fragilis H. Adams & A. Adams, 1856 in 1853–1858: 382; Conrad, 1868: 45.
Spisula (Standella) bilineata (Reeve, 1854) — Conrad, 1868: 44.
Mactra anserina Guppy, 1875: 49, pl. 7, fig.1— Dall, 1894b: 26.
Diagnosis. Shell trigonal to oval, pallial sinus rounded and deep of about half shell length, maximum length measured 85 mm (ANSP 338354); left hinge with anterior lateral teeth with two cusps, right hinge with anterior ventral lateral teeth with two cusps.
Description. Shell trigonal to oval, inequilateral, external surface smooth without ornamentation (Fig. 6 D), posterodorsal area defined by a line from umbones to posterior end and covered by a brownish periostracum; anterior end rounded, lunule not defined; ventral margin convex; internally white, right hinge with two anterior and two posterior lateral teeth, the ventral anterior with two cusps, the posterior similar in size and with one cusp; two cardinal teeth (3a & 3b) unfused (Fig. 7 A); left hinge with V-shaped cardinal tooth composed of two single cardinals (2a & 2b), one anterior and one posterior lateral tooth (AII & PII), the anterior with two cusps (Fig. 7 B). Ultrastructure of the shell with two layers as in other species here studied (Figs. 7 C–E).
Type material. [Mactra fragilis] types not found at ZMUC, ZMB and Zoological Institute of Russian Academy of Science of St. Petersburg (Martynov 2002), probably lost; [Lutraria candida] MNHN unnumbered, two syntypes; [Mactra braziliana] MNHN unnumbered, one syntype; [Mactra oblonga] ANSP 51418, one syntype; [Mactra bilineata] NHMUK unnumbered, two syntypes; [Mactra anserina] types not found at NHMUK, Guppy main collection deposited at Victoria Institute, Trinidad, destroyed by fire in 1920 (Sherborn 1940).
Type locality. Nicobar Islands, India, erroneously recorded.
Other material examined. United States of America—Myrtle Beach, North Carolina (USNM 471502, 487435); South Carolina (USNM 27020; ANSP 51417, 51419, 51418, 178514; AMNH 292619, 270166); Beaufort, South Carolina (MNRJ 1289; USNM 27015, 462356, 426251, 126104; USNM 54361); Florida (FURG 3106; USNM 54351, 124262, 604795; ANSP 43998, 175870, 132403, 186630, 51420, 76091, 174710, 158565, 189774, 174685, 180440, 387126, 88241, 76656, 354086, 264033; AMNH 210012, 311038, 139098, 131872, 121162, 125638, 100385, 248021, 172235, 248026; MZUSP 36139, 46840, 62656, 62663); Cape Canaveral (ANSP 371472); Peanut Island (AMNH 293566); Prickly Bay, Florida (ANSP 296550); Lake Worth, Florida (USNM 253194, 127259, 127259, 599286); Miami, Florida (AMNH 140442, 36058); Biscayne Bay, Florida (AMNH 120144); Caesars Creek bank (USNM 462364); Honda Bay, Florida (AMNH 309253); Sanibel (ANSP 175433, 170554; AMNH 309260, 120142, 103342, 100035, 97438, 99887); Lemon Bay (USNM 732875, 741380); Sarasota Beach, Florida (USNM 533964); Sarasota Bay, Florida (AMNH 120143); Bird Key, Tortugas (USNM 426252, 27016, 462357); Manatee River (USNM 61076, 604755); Bradenton Beach, Florida (AMNH 199586); St. Petersburg. Florida (AMNH 248820; 172236); Egmont Key, Florida (USNM 117656); Tampa Bay (USNM 27014, 462361); Cedar Key (USNM 36039, 134863, 93660); Dog Island, Apalachicola (USNM 185476); West Florida (ANSP 193681); Saint Augustine, Florida (USNM 61158); St. Andrews Bay, Florida (AMNH 266831; 266832); Texas (USNM 125653; ANSP 161372, 180061, 176590, 348776, 401045; AMNH 293567; MZUSP 13033); North of Mississippi (ANSP 209694); Palisades (USNM 442511); Old Providence (ANSP 154635); Dickinson Bay, Texas (ANSP 394662); Matagorda Bay, Texas (USNM 106996, 134410, 465242, 107376); Rockport, Texas (USNM 134411); Corpus Christi, Texas (USNM 123487). Central America—Gulf of Mexico (ANSP 338354); San Carlos Bay, Mexico (AMNH 131189); Yucatán (USNM 27017); Hopkins, Belize (ANSP 282762, 282921); Belize (USNM 777780, 771015, 771028; AMNH 183702; ANSP 285014, 282293, 284251, 284252); Honduras (NHMUK 1963.33.1–4, 4 valves, 1 illustrated by Reeve (1854)); Venado, Panama (AMNH 248509); Panama channel (USNM 743472; 783033, 821599); Randolph, Panama (USNM 759164, 759346); Panama bay (AMNH 159536); Bahamas (AMNH 168779; USNM 707309, USNM 846338; ANSP 375172; 375171); La Habana bay (ANSP 52698); Cabañas Harbour, Cuba (USNM 462366); Cárdenas Bay, Cuba (USNM 462365); Cuba (AMNH 113659); Santa Rosa, Cuba (USNM 462360); Cienfuegos, Cuba (USNM 462363; Jamaica (USNM 440799, 442762, 423771, 102894, 27018, 441315, 375542; AMNH 34065, 34901); Haiti (USNM 383300, 440449, 440227); Dominican Republic (AMNH 94720); Santa Bárbara de Samana (MNRJ 1290); Santo Domingo (ANSP 173309, 182441); Talleboa, Puerto Rico (AMNH 174); Virgin Islands (AMNH 185921, 185851); Saint Thomas (USNM 530415, 604811, 250119, 321646); Tortola (ANSP 51415); Seaforth Bay, Antigua (AMNH 311152); Saint George, Grenada (ANSP 344048, 332097; AMNH 185257); Icacos, Trinidad (ANSP 157776). Colombia—Carta-gena (USNM 517823, 364328); Puerto Colombia (USNM 543429). Venezuela—Margarita Island, (USNM 786537; MZUSP 57369, 58709, 61627); La Guaira (ANSP 264261). Brazil—Pernambuco (MZUSP 14805); Marau (MZUSP 22391); Salvador (MZUSP 28480, 44241, 44980, 44982, 45005, 59291, 59292, 59301, 77465, 77466, 81200); Bahía (MZUSP 15644, 26828, 70207; FURG 22285, 23467, 41374, 10814, 47433, 9945; ANSP 263476); Espírito Santo (MZUSP 73065); Búzios (MZUSP 48473, 57127); Niterói (MNRJ 4387); Muriqui (MNRJ 1479); Mangaratiba (MNRJ 5354); Rio de Janeiro (MNRJ 2708, 6610, USNM 17500, 120193, AMNH 34064, 34063; MACN-In 5022; MZUSP 22392, 77464, 83188, 40122); Ilha Grande (MZUSP 22316); Peruíbe (MZUSP 80834); São Sebastião (MZUSP 22398, 22401, 22402, 44203, 44244, 44997, 56205; FURG 17158); Santos (MZUSP 13042); São Paulo (MZUSP 22400, 59311, 81934); Ubatuba (MZUSP 14944, 22394, 26477); Bertioga (MZUSP 50484, 62147); Cananeia (MZUSP 83348, 83386); Ilha Bela (MZUSP 22399, 41683, 41712, 41785, 44971, 44996, 77463, 77467, 77468, 77469, 77470, 77579, 79935, 83468); Porto Belo (FURG 11784); Bombinhas (MZUSP 34588); Santa Catarina (FURG 40237, 1576, 47781; MZUSP 13041).
Distribution. From North Carolina, USA, to Santa Catarina, Brazil.
Remarks. Mactra fragilis was introduced by Chemnitz (1782). However, this work was rejected due to nomenclatorial causes (Direction 1 ICZN 1954, Opinion 184, 1944). Mactra fragilis (Gmelin, 1791), a common species living in the western Atlantic has been cited with other names, i.e.: Lutraria candida Lamarck, 1818 (Figs. 6 B–C); Mactra braziliana Lamarck, 1818 (Figs. 6 D–F); Mactra oblonga Say, 1822 (Figs. 6 G–H); Mactra bilineata Reeve, 1854 (Figs. 6 I–J) and Mactra anserina Guppy, 1875 (Fig. 6 K) which are considered synonyms according to the similarities observed in the type material. Mactra oblonga was erroneously cited by Ravenel (1834) as M. oblongata (nomen nudum).
Mactra dealbata Pulteney, 1799, later named as M. tellinoides Pulteney, 1813, is a valid species that was erroneously considered a synonym of M. fragilis by Wood and Hanley (1856), Dall (1894b), Lamy (1917), among others. This species was mentioned living along the coast of Dorset, England. Mactra ambigua Weinkauff, 1884, cited by Dall (1894b) as synonym of M. fragilis, is in fact a synonym of M. compressa Spengler, 1802, living along the northern Atlantic coast of Africa. This conclusion was drawn after the revision of Spengler´s mactrid types deposited at ZMUC. Finally, Mactra ovalina Lamarck, 1818, cited as synonym of M. fragilis by Carpenter (1855, in Carpenter, 1855 –57), Dall (1894b), and others, is a valid species living in Arabia (Bosch et al. 1995).
description: Published as part of Signorelli, Javier H. & Pastorino, Guido, 2012, Taxonomic revision of Brazilian Mactridae Lamarck, 1809 (Bivalvia: Cardiida), pp. 30-53 in Zootaxa 3245 on pages 38-42, DOI: 10.11646/zootaxa.3245.1.2, http://zenodo.org/record/6544861