Cardiomya cleryana (d’Orbigny, 1846)

Pacheco, Leonel I., Teso, Valeria & Pastorino, Guido, 2024, Use of traditional tools and micro-computed tomography for the taxonomy of carnivorous bivalves from the deep waters of Southwestern Atlantic, Zoological Journal of the Linnean Society 202, pp. 1-23 : 3-6

Cardiomya cleryana (d’Orbigny, 1846)

( Fig. 2)

Sphena cleryana d’Orbigny 1846 (in error pro Sphenia ): 572.

Sphaenia cleryana (in error pro Sphenia )—d’Orbigny 1846: 708; 1847: pl. 83, figs 16–18.

Sphenia cleryana — d’Orbigny 1853: 285.

Cuspidaria (Cardiomya) simillima E A Smith 1915: 104 , pl. 2, fig. 24— Powell 1951: 51; Figueiras and Sicardi 1970: 420, pl. vi, fig. 93; Poutiers and Bernard 1995: 166; Oliveira et al. 2017: 289, fig. 3C, D; Carcelles 1950: 83, pl. 5, fig. 96; Carcelles and Williamson 1951: 350.

Cuspidaria cleryana — Morretes 1949: 52.

Cuspidaria simillima — Castellanos 1970: 267, pl. 24, fig. 6; 1982: 41.

Cardiomya simillima — Rios 1970: 220; 1972: 197; Zelaya 2005: 117.

Cardiomya cleryana — Rios 1970: 219; 1975: 261, pl. 85, fig. 1255; 1985: 281, pl. 99, fig. 1385; 1994: 303, pl. 104, fig. 1483; 2009: 606, fig. 1678; Figueiras and Sicardi 1980: 157; Poutiers and Bernard 1995: 151; Forcelli 2000: 171, figured; Scarabino 2003: 238; Absalão et al. 2006: 223; Allen 2011: 440; Passos and Magalhães 2011: 7; Oliveira and Sartori 2014: 10, fig. 2D, E; Barroso et al. 2016: 2, in part; Machado et al. 2016, in part; Zelaya 2016: 251, table 2; Oliveira et al. 2017: 2, in part; Carvalho de Lima et al. 2020: 5 , fig. 2A–E.

Cardiomya perrostrata auct ., non Dall 1881— Rios 1975: 261, pl. 85, fig. 1257; 1985: 281, pl. 99, fig. 1387; 1994: 303, pl. 104, fig. 1485; Absalão and Pimenta 2005: 51, fig. 134.

Cardiomya cleriana (in error pro cleryana )—Layerle and Scarabino 1984: 6.

Type material: [ Sphenia cleryana ] According to Gray (1854, 1855), this material was not part of d’Orbigny’s collection deposited in NHMUK, and the holotype was never deposited. [ Cuspidaria (Cardiomya) simillima ] syntypes: NHMUK 1915.4.18.289-295, five valves; NHMUK 1915.4.18.512-515, four valves. In order to clarify the taxonomic status of Cardiomya cleryana , we designate the specimen NHMUK 1915.4.18.512, illustrated here ( Fig. 2E) as the neotype of Sphenia cleryana , in agreement with article 75.3.1-7 of the International Code of Zoological Nomenclature ( ICZN), with type locality off Rio de Janeiro state, Brazil. Ŋe specimen NHMUK 1915.4.18.512 is also a syntype of Cuspidaria (Cardiomya) simillima , thus making Cuspidaria simillima an objective junior synonym.

Type locality: [ Sphenia cleryana ] São Ŋomé cape ( Brazil), Jamaica, Cuba, Guadalupe, and Saint-Ŋomas, 80 m. [ Cuspidaria (Cardiomya) simillima ] Terra Nova Expedition station 42, off Rio de Janeiro (73 m) and station 38, west Falkland / Malvinas Islands (228 m) .

Distribution

New records: San Matías (73 m), Nuevo (55 m), and San Jorge (80–99m) Gulfs , Argentina .

Literature records: Northwest Atlantic: Off West’s Dry Rocks, FL, USA ( Carvalho de Lima et al. 2020); Southwest Atlantic: Northeastern Brazil to west of Cruz Bay, Chubut, Argentina ( Rios 1970, 1972 [‘1973’], 1975; Figueiras and Sicardi 1980 [‘1979’]; Castellanos 1982; Carvalho de Lima et al. 2020).

Bathymetry: 49–228 m.

Material examined: 35°S, 54°W, 23 m (MACN-In 23504) two valves; 36°25 ʹ S, 54°38 ʹ W, 60 m (MACN-In 23422) one valve; 41°00 ʹ 24″S, 65°00 ʹ 30″W, 73.1 m ( CFA-IN 3743 ) one individual ; ~ 42°42 ʹ S, 64°57 ʹ W, 55 m (MACN-In 29336) two valves; ~ 42°42 ʹ S, 64°57 ʹ W, 55 m (MACN-In 30368) soss material of a specimen; 44°41 ʹ 06″S, 65°21 ʹ 53″W, 83.5 m (MACN-In 43783) three individuals; 45°15 ʹ S, 65°26 ʹ W, 96 m (MACN-In 9151- 14) two valves; 45°34 ʹ 48″S, 66°07 ʹ 48″W, 83 m (MACN-In 44320) four individuals; 45°54 ʹ 12″S, 64°09 ʹ 05″W, 80.45 m (MACN-In 43784) 11 individuals; 45°55 ʹ.12″S, 65°50 ʹ 24″W, 99 m (MACN-In 44321) one individual; 46°14 ʹ 24″S, 65°49 ʹ 12″W, 98 m (MACN-In 44322) six individuals.

Description

Shell medium size (L, 15.7 ± 1.8 mm; H, 10.8 ± 1.4 mm; W, 4.3 ± 0.6 mm; N = 22), triangular to subquadrate, opaque.

Disc with 18–25 closely spaced radial ribs, well delimited from the rostrum by four or five strongly defined ribs. Rostrum with three to five weak radial lines or striae on the rostral depression. Umbo subcentral, displaced anteriorly, blunt. Rostrum moderately long (approximately half of shell length) and tube shaped. Posterodorsal margin initially straight and moderately to sharply curved upwards at the beginning of the rostrum. Anterodorsal margin short, strongly descendent, forming a short, almost obsolete shoulder in some specimens. Anterior margin truncated to rounded. Ventral margin rounded and crenulated. Posteroventral margin gently marked. Prominent, stout, and short right triangular posterior lateral tooth. Wide and slightly sunken condrophore in contact with the tooth. Anterior adductor muscle scar oval, posterior triangular. Posterior adductor, septal, and pedal muscles scars well marked, limited posteriorly by a strong ridge from the rest of the disc located interior to the posteriormost defined radial riblet. Palial line not visible. Siphonal sinus subtle and shallow.

Remarks

Ŋe original description of Cardiomya cleryana has been assigned recursively to different years: 1842 ( Poutiers and Bernard 1995, Allen 2011, Barroso et al. 2016, Machado et al. 2016, Zelaya 2016, Oliveira et al. 2017, Carvalho de Lima et al. 2020), 1845 ( Scarabino 2003), and 1846 ( Morretes 1949, Rios 1970, 1985, 1994, 2009, Passos and Magalhães 2011). Coan and Kabat (2023), in a recent collation of d’Orbigny’s ‘ Voyage dans… ’, pointed out 1846 as the date of publication for the description and 1847 for the illustrations.

EA Smith (1885) and Carvalho de Lima et al. (2020) described a rounded anterior margin and a triangular shape; however, we observed a wider variation in the studied material, including Cuspidaria simillima syntypes. Some specimens have a more truncated anterior margin, providing a more subquadrate shape ( Fig. 2A, B), whereas others ( Fig. 2C) show an intermediate form. Given that these differences in contour are found among specimens from the same locations, they are considered intraspecific variations, usually common in Cuspidariidae ( Pacheco et al. 2022) . Ŋe extreme subquadrate shape resembles Cardiomya striolata (Locard, 1898) ; nonetheless, Cardiomya striolata is more elongated and has a much weaker posteroventral sinuation and a more developed shoulder. Additionally, Cardiomya striolata has one to three radial lines on the dorsal side of the rostrum, whereas Cardiomya cleryana has them only over the rostral depression.