Panacca loveni (Jeffreys, 1882)

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 : 44

Panacca loveni (Jeffreys, 1882)

Fig. 9 j–l

Pholadomya loveni Jeffreys, 1882 [a] (p. 934, pl. 70, fig. 7).

Pholadomya loveni loveni Jeffreys, 1881 — Nordsieck 1969 (p. 158, pl. 23, fig. 92.00). Pholadomya loveni Jeffreys, 1882 — Poppe & Goto 1993 (p. 135, pl. 24, fig. 12); Repetto et al. 2005 (p. 349, bottom left fig.). Panacca loveni (Jeffreys, 1882) — Oliver et al. 2016 (online resource).

Diagnostic characters. Thin, trapezoidal shell; posterior ventral gape; short, subtruncate posterior side; long anterior side with rounded margin; subhorizontal and twisted resilial socket; irregular, wavy radial ribs over the mid-valve; minute pustules throughout, often arranged in radial rows. Prodissoconch: shell type ST-2C; length about 220 µm (P-1 about 180 µm); roundish outline; low convex profile; P-1 surface weakly rough; P-1/P-2 boundary step-like; P-2 narrow and flattened, with few commarginal lines; transition to the nepioconch distinct.

Remarks. The specimens figured by Oliver et al. (2010) have a trigonal, wedge-shaped outline markedly different from the original figure by Jeffreys (1882). They are otherwise identical to our specimens. We regard this shape discrepancy as intraspecific variability, therefore.

Occurrence. Box-corer samples BC05 (3 specimens), BC11 (1), BC66 (3), BC70 (1), BC72 (4); cores BC05 (2), BC21 (6), BC51 (1), BC67 (1), BC72 (4). Maximum length: 30 mm.

Distribution and habitat. Panacca loveni is commonly found at shelf depths and down to 2000 m in the Azores and Mediterranean waters, being very rare in northern seas where it reachs the intertidal zone ( Poppe & Goto 1993; Oliver et al. 2016).

Fossil record. Bathyal Pleistocene of Sardinia ( Di Geronimo & Bellagamba 1985).

Figures

FIGURE 9. a – d: Kelliella miliaris (Philippi, 1844); RV (a, c) and LV (b, d), sample BC 72, scale bars: 1 mm (a – c), 0.1 mm (d, prodissoconch); e – f: Hiatella arctica (Linnaeus, 1767); RV, sample BC 70, scale bar 5 mm; g – i: Xylophaga dorsalis (Turton, 1819); RV, samples BC 66 (h – i) and BC 72 (g), scale bars: 0.5 mm (g – h), 0.1 mm (i, prodissoconch); j – l: Panacca loveni (Jeffreys, 1882); LV, samples BC 70 (j – k) and BC 05 (l), scale bars 10 mm (j – k), 0.1 mm (l, prodissoconch); m – o: Panacca? sp.; RV (m, n) and LV (o), sample BC 72, scale bars: 5 mm (m – n), 0.1 mm (o, prodissoconch; the arrow points at the ventral sinuation).