Asperarca nodulosa ( Müller, 1776 ), Muller, 1776

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 : 20-21

Asperarca nodulosa ( Müller, 1776)

Fig. 3 j–m

Arca nodulosa Müller, 1776 (p. 247, n. 2984).

Arca nodulosa Müller—Jeffreys 1879 (p. 570).

Acar nodulosa nodulosa ( Müller, 1776) — Nordsieck 1969 (p. 21, pl. 3, fig. 10.30).

Acar nodulosa scabra (Poli, 1795) — Nordsieck 1969 (p. 21, pl. 3, fig. 10.31).

? Barbatia nodulosa (Mull.), 1776 — Sirna & Masullo 1978 (p. 104, pl. 1, fig. 4).

Acar nodulosa scabra (Poli) —Di Geronimo 1979[a] (p. 135, pl. 6, figs. 1–3).

Barbatia nodulosa (O.F. Müller, 1766) — Poppe & Goto 1993 (p. 43, pl., fig. 1).

? Barbatia scabra (Poli, 1795) — Salas 1996 (p. 46).

Asperarca nodulosa ( Müller, 1776) — La Perna 1998 (p. 11, pl. 2, figs. 1–4; pl. 3, fig. 5); Mastrototaro et al. 2010 (fig. 5 f); Oliver et al. 2016 (online resource).

Asperarca nodulosa ( O.F. Müller, 1776) — Giannuzzi-Savelli et al. 2001 (p. 70, figs. 82–86); De Frias Martins et al. 2009 (p. 67, fig. 300).

Asperarca nodulosa (Mueller O.F., 1776) — Repetto et al. 2005 (p. 286, mid left fig). Asperarca nodulosa ( Müller O.F., 1776) — Beck et al. 2006 (p. 94, bottom fig). Asperarca nodulosa (Mueller) —Rosso et al. 2010 (figs. 5 A, 14 L).

Diagnostic characters. Brownish subrectangular shell; gentle but distinct ventral sinuation; obtuse angulation running from beaks to postero-ventral margin; uneven commarginal folds crossed by several radial riblets developing into short, fluted spines above the posterior angulation. Prodissoconch: shell type ST-2D; length about 190 µm; roundish D-shaped outline; convex profile; P-1 with a small dorsocentral bump; P-1 surface sculpture somewhat eroded, appearing weakly rough, with faint antimarginal striation; P-2 a very narrow rim, barely separated from P-1; transition to the nepioconch well marked, somewhat step-like.

Remarks. The recently described A. secreta ( La Perna, 1998) appears to be the most closely related taxon, differing primarily in having much smaller dimensions (4 mm vs. 15 mm); see La Perna (1998) for a complete comparison.

Occurrence. Box-corer samples BC04 (4 specimens), BC05 (5), BC10 (1), BC11 (5), BC22 (28), BC41 (1), BC66 (46), BC67 (12), BC68 (1), BC70 (1), BC71 (54), BC72 (27); cores BC04 (2), BC05 (9), BC21 (6), BC51 (18), BC67 (17), BC72 (7). Maximum length: 12.5 mm.

Distribution and habitat. Asperarca nodulosa occurs from the subarctic ( Norway) to West Africa and into the Mediterranean. It lives attached by byssus to deep water corals, stones and gravel, gradually moving from shelf to bathyal depths going southwards, thus showing both a cold-temperate and eurybathic adaptation ( Poppe & Goto 1993; La Perna 1998; Oliver et al. 2016). It was regarded as a preferential or accompanying element of CB (deepsea white corals) biocoenosis ( Pérès & Picard 1964; Di Geronimo 1979[a]; Di Geronimo & Bellagamba 1985). In the Santa Maria di Leuca CWC biotope, it was found on dead colonies of Madrepora oculata and hard substrates (Mastrototaro et al. 2010), being abundant in framework-building coral, and common in coral rubble and solitary coral thanatofacies, as well as on hardgrounds (Rosso et al. 2010).

Fossil record. Miocene to Recent ( Monegatti & Raffi 2001); very common in bathyal Pleistocene of central and southern Italy, often referred to as Acar or Barbatia scabra ( Monterosato 1872; Di Geronimo 1979[a]; Di Geronimo & Bellagamba 1985; Di Geronimo & La Perna 1997; La Perna 1998; Di Geronimo et al. 2005).

Figures

FIGURE 3. a – c: Yoldiella nana (Sars M., 1865); RV (b, c) and LV (a), sample BC 72, scale bars: 0.5 mm (a – b), 0.1 mm (c, prodissoconch); d – f: Yoldiella philippiana (Nyst, 1844); RV, sample BC 72, scale bars: 1 mm (d – e), 0.1 mm (f, prodissoconch); g – i: Yoldiella striolata (Brugnone, 1876); RV, sample BC 72, scale bars: 1 mm (g – h), 0.1 mm (i, prodissoconch); j – m: Asperarca nodulosa (Müller, 1776); LV, sample BC 11, scale bars: 5 mm (j – k), 1 mm (l, juvenile), 0.1 mm (m, prodissoconch).