Bathyarca pectunculoides ( Scacchi, 1835 )

Negri, Mauro Pietro & Corselli, Cesare, 2016, Bathyal Mollusca from the cold-water coral biotope of Santa Maria di Leuca (Apulian margin, southern Italy), Zootaxa 4186 (1), pp. 1-97 : 21-23

Bathyarca pectunculoides ( Scacchi, 1835)

Fig. 4 a–c

Arca pectunculoides Scacchi, 1835 (p. 82, pl. 1, fig. 12).

Arca pectunculoïdes [sic] Scacchi—Jeffreys 1879 (p. 572).

Arca pectunculoides Scacchi—Hidalgo 1917 (p. 147).

Bathyarca pectunculoides pectunculoides (Scacchi, 1836) — Nordsieck 1969 (p. 22, pl. 3, fig. 10.40).

Bathyarca pectunculoides (Scacchi) — Di Geronimo & Panetta 1973 (p. 96, pl. 3, fig. 8); Di Geronimo & Li Gioi, 1980 (pl. 2, figs. 7–8).

Bathyarca pectunculoides (Scacchi), 1833 — Sirna & Masullo 1978 (p. 105, pl. 1, fig. 8).

Bathyarca pectunculoides (Scacchi, 1833) — Thomsen & Vorren 1986 (pl. 4, fig. A).

Bathyarca pectunculoides (Scacchi, 1836) — Barash & Danin 1992 (p. 234).

Bathyarca pectunculoides (Scacchi, 1834) — Salas 1996 (p. 46); Giribet & Peñas 1997 (fig. 94); Giannuzzi-Savelli et al. 2001 (p. 80, fig. 103); Repetto et al. 2005 (p. 287, mid left fig.); Beck et al. 2006 (p. 95, mid fig).

Bathyarca pectunculoides ( Scacchi, 1835) — Oliver et al. 2016 (online resource).

Diagnostic characters. Roundish trapezoidal shell, slightly more extended posteroventrally; blunt antero-ventral sinuation; outer surface with uneven growth markings and faint radial riblets. Prodissoconch: shell type ST-2D; length about 160 µm; roundish D-shaped outline; convex profile; P-1 surface smooth; P-2 reduced to metamorphic lip, barely separated from P-1; transition to the nepioconch well marked, somewhat step-like.

Occurrence. Box-corer samples BC04 (21 specimens), BC05 (20), BC06 (1), BC66 (6), BC67 (4), BC71 (4), BC72 (65); cores BC04 (6), BC05 (74), BC21 (21), BC51 (25), BC52 (1), BC67 (1), BC72 (30). Maximum length: 4.5 mm.

Distribution and habitat. Bathyarca pectunculoides is distributed from Greenland, Iceland and Norway to the Gulf of Mexico, the Azores, the Canaries and the Mediterranean, including the Levantine basin; it lives attached by byssus to stones and gravel from the shelf edge to bathyal depths, often associated with brachiopods ( Nordsieck 1969; Barash & Danin 1992; Buhl-Mortensen & Høisaeter 1993; Pons-Moyà & Pons 1999; Galil 2004; Oliver et al. 2016). It belongs to the Abra-Nucula biocoenosis in the bathyal of Taranto ( Di Geronimo & Panetta 1973), and was regarded as an accompanying element in VP (bathyal mud) and CB (deep-sea white corals) biocoenoses ( Di Geronimo & Bellagamba 1985). In the Santa Maria di Leuca CWC biotope, it was found on the muddy bottoms around the coral colonies (Mastrototaro et al. 2010).

Fossil record. Miocene of central Italy ( Sirna & Masullo 1978); Pliocene of Italy ( Monterosato 1872; Tabanelli 2008); bathyal Pleistocene of Sardinia ( Di Geronimo & Li Gioi 1980; Di Geronimo & Bellagamba 1985). The species was originally described on fossil material.

Figures

FIGURE 4. a – c: Bathyarca pectunculoides (Scacchi, 1835); RV (a, b) and LV (c), sample BC 72, scale bars: 1 mm (a – b), 0.1 mm (c, prodissoconch); d – f: Bathyarca philippiana (Nyst, 1848); LV, sample BC 04, scale bars: 2 mm (d – e), 0.1 mm (f, prodissoconch); g – i: Dacrydium hyalinum (Monterosato, 1875); LV, sample BC 72, scale bars: 1 mm (g – h), 0.1 mm (i, prodissoconch); j – m: Pseudamussium peslutrae? (Linnaeus, 1771); LV, sample BC 67, scale bars: 2 mm (j – k), 0.1 mm (l, prodissoconch), 0.05 mm (m, P – 1 detail); n – q: Karnekampia sulcata (Müller, 1776); RV (o – q) and LV (n), sample BC 72, scale bars: 5 mm (n – p), 0.1 mm (q, prodissoconch).