Cardiomya perrostrata (Dall, 1881)

Figs 1, 2, 4

Neaera ornatissima var. perrostrata Dall, 1881, p. 110.

Neaera perrostrata Dall—Verrill 1881 –1882, p. 561 [July, 1882].

Neaera perrostrata (Dall) — Verrill 1882, p. 340.

Neaera perrostrata Dall—Verrill 1884, pp. 277, 285.

Cuspidaria (Cardiomya) perrostrata Dall—Dall 1886, pp. 296-297, pl. II, figs 3a–b.

Cuspidaria (Cardiomya) perrostrata Dall—Dall 1889, pp. 66–67, 177 [as Cardiomya perrostrata], pl. II, figs 3a–b [reproduction of figure by Dall 1886].

Cardiomya perrostrata — E.A. Smith 1889, p. 424.

Cardiomya perrostrata Dall—Verrill & Bush 1898, p. 809, pl. LXXIV, fig. 3 [but not pl. LXXIII, fig. 2].

Cardiomya abyssicola —* Verrill & Bush 1898, pp. 806–808, in part, pl. 74, fig. 1 [non Cardiomya abyssicola Verrill & Bush 1898, pl. 73, fig. 4, pl. 77, fig. 9].

Cuspidaria perrostrata Dall—? Dall & Simpson 1901, pp. 497, 513.

Cuspidaria perrostrata Dall—Verco 1908, p. 201.

Cuspidaria (Cardiomya) perrostrata (Dall) — Johnson 1915, p. 42.

Cuspidaria (Cardiomya) perrostrata Dall 1881 — Johnson 1934, p. 34.

Cuspidaria perrostrata Dall—? McLean 1936, p. 119.

Cuspidaria (Cardiomya) perrostrata Dall—McLean 1951, p. 49, pl. 10, fig. 2 [reproduction of figure by Dall, 1886].

Cuspidaria perrostrata Dall—M. Smith 1951, p. 42, pl. 61, figs 3a–b [reproduction of figure by Dall, 1886].

Cardiomya perrostrata Dall—Poirier 1954, p. 186.

Cuspidaria perrostrata —?Parker 1956, tables 1, 2.

Cuspidaria perrostrata Dall 1881 —? Parker & Curray 1956, table 1.

NOT Cardiomya perrostrata Dall, 1881 — Warmke & Abbott 1961, p. 211, pl. 44, fig. D [= Cardiomya cf. ornatissima].

Cardiomya perrostrata Dall—? Warmke & Erdman 1963, table 1.

Cardiomya perrostrata Dall—Wagner & Abbott 1964, p. 164.

NOT Cardiomya perrostrata Dall—Rice & Kornicker 1965, p. 138, table 2, pl. 16, fig. 15 [= Cardiomya sp.].

Cardiomya perrostrata Dall—Wagner & Abbott 1967, p. 243.

Cardiomya perrostrata (Dall) —? Radwin 1969, p. 233.

Cardiomya perrostrata (Dall, 1881) —*? Rios 1969, p. 10.

Cardiomya perrostrata (Dall, 1881) —*? Rios 1970, p. 220.

Cuspidaria perrostrata Dall—Altena 1971, pp. 79, 80 [as Cardiomya perrostrata (Dall)].

NOT Cardiomya perrostrata (Dall) — Morris 1973, p. 105, pl. 34, fig. 10 [= C. alternata (d’Orbigny, 1853)].

Cardiomya perrostrata — Odé 1973, p. 83.

Cuspidaria perrostrata —? Wigley & Stinton 1973, pp. 16, 17, tables 4, 7, figs 9, 10 [plots of distribution and bathymetric range].

Cardiomya perrostrata (Dall, 1881) — Abbott 1974, p. 567, fig. 6213 [reproduction of figure by Dall, 1886].

Cardiomya abyssicola (Verrill and Bush, 1898) — Abbott 1974, p. 567, fig. 6216 [reproduction of figure by Verrill and Bush, 1898] [non Cardiomya abyssicola Verrill & Bush 1898, pl. 73, fig. 4, pl. 77, fig. 9].

Cardiomya perrostrata Dall 1881 — Humfrey 1975, p. 286.

NOT Cardiomya perrostrata (Dall, 1881) — Rios 1975, p. 261, pl. 85, fig. 1257 [= C. cleryana].

Cardiomya perrostrata —? Blake et al. 1977, tables 3, 4.

Cardiomya perrostrata Dall, 1881 — Odé 1977, p. 107.

Cardiomya perrostrata —? Bishof 1980, p. 44, tables 2, 4, 5, 7, 9–11, 16, 17, 21, 22, fig. 7 [plot of ecological dominance].

Cuspidaria (Cardiomya) perrostrata (Dall, 1881) — Allen & Morgan 1981, pp. 461–464, figs 27, 28.

Cardiomya perrostrata (Dall, 1881) —*?M.P.d. Oliveira et al. 1981, p. 503.

Cardiomya perrostrata (Dall 1881) —? Wigley & Theroux 1981, table 4.

Cardiomya perrostrata —? Hill et al. 1982, table 3.

Cardiomya perrostrata (Dall 1881) — Theroux & Wigley 1983, p. 56, tables 5, 312, 313, fig. 22.

Cuspidaria perrostrata —? Maurer & Wigley 1984, p. 8, appendix table 2.

Cardiomya perrostrata (Dall, 1881) —? Maciolek-Blake et al. 1985, p. B-8.

NOT Cardiomya perrostrata (Dall, 1881) — Rios 1985, p. 281, pl. 99, fig. 1387 [= C. cleryana].

Cardiomya perrostrata (Dall, 1881) — Turgeon 1985, p. 82.

Cardiomya perrostrata —?Woodward-Clyde Consultants & Continental Shelf Associates 1985, pp. B-54, B-305, B-310, B-320, B-382.

Cardiomya perrostrata (Dall, 1881) — Turgeon et al. 1988, p. 49.

Cardiomya perrostrata (Dall, 1881) —? Espinosa et al. 1994, p. 126.

Cardiomya perrostrata (Dall, 1881) —? Hilbig 1994, p. 945.

NOT Cardiomya perrostrata (Dall, 1881) — Rios 1994, p. 303, pl. 104, fig. 1485 [= C. cleryana].

Cardiomya perrostrata (Dall, 1881) — Espinosa et al. 1995, p. 79.

Cardiomya (Cardiomya) perrostrata — Poutiers & Bernard 1995, pp. 151, 165.

Cardiomya perrostrata (Dall, 1881) —? Theroux & Wigley 1998, table 4.

Cardiomya perrostrata (Dall, 1881) — Turgeon et al. 1998, p. 53.

Cardiomya perrostrata —?Vittor & associates 1998, table 2.

Cardiomya perrostrata Dall, 1881 —? Carlos & Joaquín 1999 [“1998”], p. 150.

Cardiomya perrostrata —?Vittor & associates 1999, table 2.

Cardiomya perrostrata (Dall, 1881) — Mikkelsen & Bieler 2000, p. 373.

Cardiomya perrostrata (Dall, 1881) —? Soares-Gomes & Pires-Vanin 2003, p. 720.

Cardiomya perrostrata (Dall, 1881) —?Bieler & Mikkelsen 2004, p. 512.

Cardiomya perrostrata (Dall, 1881) —Mikkelsen & Bieler 2004, p. 595.

Cardiomya perrostrata —*? Pimpão 2004, p. 137.

NOT Cardiomya perrostrata — Absalão & Pimenta 2005, p. 51, fig. 134 [= C. cleryana].

Cardiomya perrostrata (Dall, 1881) —? Agudo & Bleicker 2005, p. 6.

Cardiomya perrostrata —? Muniz & Pires-Vanin 2005, appendix 1.

Cardiomya perrostrata (Dall, 1881) —?Soares-Gomes & Fernandes 2005, pp. 75, 76.

Cardiomya perrostrata —? Soares-Gomes & Pires-Vanin 2005, pp. 722, 723.

NOT Cardiomya perrostrata (Dall, 1881) — Absalão et al. 2006, p. 258 [= C. cleryana and/or C. ornatissima].

Cardiomya perrostrata (Dall, 1881) —? García 2007, p. 6.

NOT Cardiomya perrostrata (Dall, 1881) —* Mikkelsen & Bieler 2007 [“2008”], p. 224, figured [= variety of C. alternata].

Cardiomya perrostrata (Dall, 1881) — Raffucci 2007, p. [67].

Cardiomya perrostrata Dall, 1881 —? Villalobos 2007, pp. 31 [as ‘perrustrata’], 34, 83, 119.

Cardiomya perrostrata —? Wysong 2008, pp. 69, 82, 87.

Cardiomya perrostrata (Dall, 1881) —? Agudo-Padrón et al. 2009, p. 14.

NOT Cardiomya perrostrata (Dall, 1881) — Rios 2009, p. 606, figured [= C. cleryana].

Cardiomya perrostrata (Dall, 1881) — Turgeon et al. 2009, p. 738.

Cardiomya perrostrata (W. H. Dall 1881) — Huber 2010, Chapter 5.

Cardiomya perrostrata (Dall 1881) — Allen 2011, p. 440.

Cardiomya perrostrata —? Amaral & Nallin 2011, p. 570.

Cardiomya perrostrata —?Amaral et al. 2011, p. 458.

Cardiomya perrostrata (Dall, 1881) —? Arruda et al. 2011, p. 242.

Cardiomya perrostrata (Dall, 1881) —? Gracia et al. 2012, table 1.

Cardiomya perrostrata — Hebbeln et al. 2012, Appendix 2-10 (unnumbered figure).

Cardiomya perrostrata (Dall, 1881) — C. D.d. C. Oliveira 2012, p. 9.

Cardiomya perrostrata (Dall, 1881) —? Correa-Sandoval & Rodríguez-Castro 2013, pp. 567, 577.

Cardiomya perrostrata (Dall, 1881) — Petuch & Myers 2014, pp. 197, 210, 276.

Cardiomya perrostrata (Dall, 1881) —? Agudo-Padrón 2015, p. 72.

Cardiomya perrostrata (W. H. Dall 1881) — Huber 2015, Chapter 5.

NOT Cardiomya perrostrata (Dall, 1881) —* Barroso et al. 2016, pp. [9–11], fig. 7 [= variety of C. alternata and Cardiomya sp.].

NOT Cardiomya perrostrata (Dall, 1881) —* Machado et al. 2016, figs 1a–b [= Cardiomya sp. and C. cleryana].

Type-locality. Blake Expedition, sta. 43 (24°08’00”N; 82°51’00”W; 620m). United States, Florida, off Dry Tortugas .

Redescription. Shell small (max. height: 13 mm; max. length: 25 mm, USNM 95 393), inequivalve, with left valve slightly overlapping right valve along ventral margin. Shell flank globose, umbones prominent and blunt. Rostrum elongated, longer and more curved in larger specimens. Posterior margin slightly curved upwards, posteroventral sinuation gently marked, crenulated, ventral and anterior margins rounded, anterodorsal margin forming a well-marked shoulder. Larval shell type 2D, ca. 215–235 µ m in length. Nepioconch smooth, ca. 1 mm in length. Dissoconch with 20–25 radial ribs, the 4–5 strongest ribs ornament the posterior end of the shell flank, just anterior to the rostrum; rostrum with 7–10 radial riblets and arenophilic lines. Periostracum minutely pitted. Hinge plate narrow, left valve edentulous, right valve with strong posterior lateral tooth. Lithodesma present.

Remarks. Figure 2 A illustrates the largest shell studied herein, measuring 25 mm in length. This seems to be the only known individual of C. perrostrata with a shell length exceeding 10 mm; most valves of the species range from 6–10 mm in length.

Cardiomya perrostrata displays a gradual increase in the relative length of the rostrum during its ontogeny and in larger specimens the rostrum is more prominently curved upwards (Fig. 1). Some individual variation is also observed in the strength of radial ribs, especially those at the posterior half of the shell. Variation in these features, which are regarded as diagnostic for Cardiomya species, is probably the main culprit for the high incidence of misidentifications of C. perrostrata in the literature. It is most often confused with C. ornatissima (Orbigny, 1853 in 1842–1853), C. cleryana (Orbigny, 1842 in 1834–1847) and C. striata (Jeffreys, 1876) .

Cardiomya ornatissima (Fig. 3 A) differs from C. perrostrata in displaying fewer (4–6) and more widely spaced radial ribs, particularly towards the posterior margin. Additionally, in C. ornatissima the rostrum is curved downwards and the posteroventral sinuation is not marked.

Cardiomya cleryana (Fig. 3 B) can be distinguished from C. perrostrata by its shorter rostrum, posteroventral sinuation gently curved and shell trigonal to elliptical.

Cardiomya striata (Fig. 3 C) differs from Cardiomya perrostrata in having an elliptical shell, larger umbones, shorter rostrum, and radial ribs that are equidistant and more or less equal in prominence.

Geographic distribution. Figure 4 plots all records of C. perrostrata known to us. The majority of records originate from checklists and ecological studies that are insufficiently illustrated and usually unvouchered (Appendix 1). Records for which we could corroborate the correct identification of C. perrostrata by the examination of vouchers or figures were plotted as triangles on the map.

The distribution of C. perrostrata is Western Atlantic, with records ranging from 42°N (Gulf of Maine) to 30°S (Tramandaí, Brazil), in depths of 18 m (Bishof 1980) to 1646–1829 m (USNM 811156). Mean depth of records is 381.9 m (median = 223.8 m), but we could only confirm the taxonomic identification of four records shallower than 200 m . If only verified records are considered, the species mean depth is 582.6 m (median = 620 m) (Fig. 4A).

Confirmed occurrences are as follows (See the discussion section for notes on records marked with “?”): United States, Massachusetts, South of Martha’s Vineyard, around Block and Alvim canyons (Allen & Morgan 1981; Verrill 1881 – 1882; Verrill & Bush 1898); off Miame, USNM 95527, USNM 330569, USNM 432665 ; off Fowey Rocks, USNM 83149; off Fowey Light, USNM 458608, USNM 458632, USNM 458650, USNM 458651, USNM 458657, USNM 458659, USNM 458660, USNM 458664, USNM 458861, USNM 458866, USNM 458869; off Dry Tortugas (type-locality, Dall 1881); Gulf of Mexico, Campeche Bank (Hebbeln et al. 2012); off Cape San Blas, USNM 323764; Louisiana, Southeast of Mississippi Delta, USNM 811156, USNM 94005; West Indies (Warmke & Abbott 1961?); Puerto Rico? (Dall & Simpson 1901); Lesser Antilles, off Montserrat, USNM 95393 ; off Grenada (Dall 1886); Southwest Atlantic, Brazil, Rio de Janeiro, off Bacia de Campos, MNRJ 17080, MNRJ 25568, MNRJ 25605, MNRJ 27011, MNRJ 27082, MNRJ 30859, IBUFRJ 14985, IBUFRJ 15022, IBUFRJ 15323, IBUFRJ 15504, IBUFRJ 15625, IBUFRJ 16062, IBUFRJ 17039, IBUFRJ 17145, IBUFRJ 17616, IBUFRJ 17618, IBUFRJ 17621, IBUFRJ 18247, IBUFRJ 20050, IBUFRJ 20051, IBUFRJ 20052, IBUFRJ 20948, IBUFRJ 20949, IBUFRJ 20950, IBUFRJ 20951; South of Maricá, IBUFRJ 2366.