Pleurotomella demosia ( Dautzenberg & Fischer, 1896 )

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 : 69

Pleurotomella demosia ( Dautzenberg & Fischer, 1896)

Fig. 15 q–t

Pleurotoma demosia Dautzenberg & Fischer, 1896 (p. 429, pl. 15, fig. 12).

Pleurotomella (Gymnobela) demosia (Dautzenberg & H. Fischer) — Nordsieck 1968 (p. 183, pl. 31, fig. 95.64).

Pleurotomella (Gymnobela) demosia ( Dautzenberg & Fischer, 1896) — Nordsieck 1977 (p. 67, pl. 26, fig. 136).

Pleurotomella demosia ( Dautzenberg & Fischer, 1896) — Bouchet & Warén 1980 (p. 39, figs. 91, 226); Beck et al., 2006 (p. 81, bottom fig.).

Pleurotomella demosia ( Dautzenberg and Fischer, 1896) — Poppe & Goto 1991 (p. 173, pl. I, fig. 28).

Pleurotomella demosia (Dautzenber y Fischer, 1896)— Giribet & Peñas 1997 (p. 74, figs. 66–68).

Pleurotomella demosia ( Dautzenberg & Fischer H., 1896) — Repetto et al. 2005 (p. 215, top left fig.).

Pleurotomella demosia ( Dautzenberg y H. Fischer, 1896)— Peñas et al. 2006 (p. 126, figs. 252, 277–278).

Pleurotomella demosia (Dautzenberg & Fisher H., 1896) — Crocetta & Spanu 2008 (p. 72, figs. 3A–B).

Diagnostic characters. Fusiform shell; spire whorls angular; subhorizontal subsutural shelf giving the spire a stepped appearance; oval aperture; short and wide siphonal canal; rather narrow U-shaped anal sinus; 12 to 16 rounded collabral ribs per whorl; superimposed thin spiral cords rapidly increasing in number by intercalation during growth; nodules at the intersections of ribs and cords. Protoconch: conical; 3 whorls; diameter about 530 µm (protoconch I: 310 µm); height about 560 µm; first 1.5 whorls (protoconch I) with spirally connected T-shaped granules forming a square reticulated pattern; subsequent whorls (protoconch II) with an oblique reticulated pattern of sinuous, collabral axial riblets and non-collabral prosocline riblets; the latter riblets absent in the adapical fourth, where only collabral riblets are present; transition to the teleoconch marked at a sinusigera.

Occurrence. Box-corer samples BC71 (11 specimens), BC72 (1). Maximum height: 10 mm.

Distribution and habitat. Pleurotomella demosia is distributed from the northeastern Atlantic southward to the Lusitanic province and the Mediterranean, in the 120–1980 m depth interval ( Bouchet & Warén 1980; Poppe & Goto 1991; Bouchet & Taviani 1992). In Sardinian waters, it was found associated with a deep water population of Corallium rubrum ( Crocetta & Spanu 2008) .

Fossil record. None recorded.

Figures

FIGURE 15. a – d: Drilliola loprestiana (Calcara, 1841), sample BC 05, scale bars: 1 mm (a), 0.5 mm (b – c, protoconch), 0.1 mm (d, PI detail); e – h: Mangelia nuperrima (Tiberi, 1855), samples BC 05 (e) and BC 72 (f – h), scale bars: 2 mm (e), 0.5 mm (f – g, protoconch), 0.1 mm (h, PI detail); i: Mangelia serga (Dall, 1881), sample BC 72, scale bar 2 mm; j – l: Pleurotomella eurybrocha (Dautzenberg & Fischer, 1896), sample BC 21, scale bars: 0.5 mm (j), 0.2 mm (k – l, protoconch); m – p: Teretia teres (Reeve, 1844), sample BC 72, scale bars: 1 mm (m), 0.2 mm (n – o, protoconch), 0.1 mm (p, PI detail); q – t: Pleurotomella demosia (Dautzenberg & Fischer, 1896), sample BC 71, scale bars: 2 mm (q), 0.2 mm (r – s, protoconch), 0.1 mm (t, PI detail).