Mitromorpha (Mitrolumna) nofronii, Amati, Bruno, Smriglio, Carlo & Oliverio, Marco, 2015

Amati, Bruno, Smriglio, Carlo & Oliverio, Marco, 2015, Revision of the Recent Mediterranean species of Mitromorpha Carpenter, 1865 (Gastropoda, Conoidea, Mitromorphidae) with the description of seven new species, Zootaxa 3931 (2), pp. 151-195 : 180

Mitromorpha (Mitrolumna) nofronii n. sp.

( Figs 17 ; 25A–J; 27P, Q; 28K)

Type material. Holotype, Gorgona Is., northern Tyrrhenian Sea, - 400 m, Italo Nofroni leg., (H 5.75 mm, W 2.9 mm) ( MNHN, IM- 2000-27711) (Fig.), paratypes: 5 sh, type locality, ix.1979 (IN); 1 sh, Capraia Is., 250–280 m, 1979 (BA).

Type locality. Gorgona Is., Central Tyrrhenian Sea, - 400 m.

Other material examined. Italy: Santa Lucia Bank, Central Tyrrhenian Sea, 440 m, ‘white corals’ bioclastic coarse sediment, 1996 6 sh juv. (CS); Capraia Is., Central Tyrrhenian Sea, 250–280 m, 1978, 1 sh juv. (BA); Mediterranean Sea (unspecified locality and depth) ‘ex Giglioli 82’, 5 sh ( MCZR, coll. Monterosato, M- 21-17319);

Etymology. Dedicated to our dear friend Italo Nofroni (Roma), expert malacologist.

Distribution and habitat. Known from the Central Tyrrhenian Sea. Recent. Empty shells in bioclastic sediments, from 250– 440 m. Found sympatric, often at different depths, with M. olivoidea , M. bogii n. sp., M. columbellaria and M. karpathoensis .

Description. (in parentheses the data of the holotype) Shell small for the genus ( Figs 25 A–J; 27P, Q), height 5–6.25 (5.75 mm), width 2.45–3.25 (2.9). Solid, fusiform, biconic, slender, H/W=1.923–2.040 (1.982). Protoconch paucispiral ( Fig. 28K ) shiny, blunt, of 1.3–1.5 (1.5) convex whorl, d 0.20–0.25 (0.20 mm), Do 0.40–0.50 (0.45 mm), DM 0.575–0.65 (0.60 mm), h 0.45–0.65 (0.50 mm), sculptured by rare microgranules. Protoconch-teleoconch boundary well marked, slightly flexuose, opisthocline. Teleoconch of da 3.8–4.3 (4) slightly convex whorls. Sculpture starting with 3–4 (4) fine spiral cordlets crossed by 16 fine axial ribs on the first whorl. Additional spiral cordlets between the adapical ones and between the suprasutural one and the suture. Penultimate whorl with 4–5 (4) spirals. Last whorl sculptured over the entire surface by 25–31 (25) spiral cordlets, of which 6–7 (7) above the aperture: the six most adapical rather strong and broader than the intespaces; those on the periphery finer, flat and closer each other; the 13–14 on the base stronger and more spaced. Axial ribs present only on the first 3 whorls, producing rounded nodules and quadrangular interspaces at the intersection with the spirals. Two columellar folds, the posterior stronger and slightly flatter. Growth lines visible over the entire surface. Outer lip sharp, thickened internally with 6 (6) weak denticles, the second or third posterior more pronounced. Anal sinus well marked. Siphonal canal short, and wide. Coloration light caramel in the background (including the protoconch) with lighter and darker blotches on the periphery. Outer lip lighter with lighter coloration in correspondence of the anal sinus and occasionally darker blotches on the median part. Soft parts unknown.

Remarks. M. nofronii n. sp. is a deep water species, characterized by a medium sized shell, and a feeble coloration with faint blotches. It is similar to M. karpathoensis and M. wilhelminae , in the chromatic pattern, which is however fainter. Furthermore, M. wilhelminae ( Figs 14 A–K; 15A–I; 27I –L) has fewer spirals on the last whorl (19– 20 v. 25–31 of M. nofronii n. sp.) and a higher ratio H/W (2.064–2.133 v. 1.923–2.040). M. olivoidea ( Figs 8 A–O; 9A–E; 27G) as more spirals on the last whorl (34–39), and above the aperture (8– 11 v. 6–7). M. bogii n. sp. has a monochrome shell (white or light brown), is larger and has more spirals above the aperture (7–10).

Figures

FIGURE 8. Mitromorpha olivoidea (Cantraine, 1835). A – B. lectotype of Mitra olivoidea Cantraine, ‘ Mediterraneo’, H = 8.3 mm (IRSN, IG 3354); C – D. Holotype of Mitromorpha melitensis (Mifsud, 1993), Malta, H = 9 mm (MZB- 011673); E – H. Cala Gonone, Sardegna, Italy, H = 9.2 mm (BA); I. Marina di Camerota 90 m, Italy, H = 9 mm (CS); J – K. Elba Is., Italy, H = 7.2 mm (MCZR, M- 21 - 17319); L-M. Palermo, Italy, H = 7.3 mm (MCZR, M- 21 - 17319); N – O: S. Vito lo Capo, Italy, H = 7.75 mm (MCZR, M- 21 - 17319).

FIGURE 14. Mitromorpha wilhelminae (Aartsen, Menkhorst & Gittenberger, 1984). A – C. Alboran Is., Spain, 17 m, H = 7.9 mm (MO); G. Alboran Is., Spain, 17 m, close-up of the first whorls (MO); D – F. Alboran Is., Spain, 17 m, juvenile, H = 3.55 mm (MO); H. Alboran Sea, Spain, white specimens, H = 7.4 mm (PC); I. Alboran Is., Spain, 17 m, white specimens, H = 6.6 mm (IN), J – K. Alboran Is., Spain, 17 m, juvenile white specimen, H = 4.6 mm (IN).

FIGURE 17. Distribution of Mitromorpha spp. based on the type material and the material examined in this work. Closed circles, Mitromorpha wilhelminae (van Aartsen, Menkhorst & Gittenberger, 1984). Grey circle, Mitromorpha alyssae n. sp. Open circles, Mitromorpha nofronii n. sp. Black box, Mitromorpha mifsudi n. sp. Open box, Mitromorpha mariottinii n. sp. Grey box, Mitromorpha cossyrae n. sp. Star, Mitromorpha tricolorata n. sp.

FIGURE 25. Mitromorpha nofronii sp. n.. A – C. Holotype, Gorgona Is., H = 5.75 mm (MNHN, IM- 2000 - 27711); D – E. Mediterranean Sea (coll. Monterosato ex Giglioli, MCZR, M- 21 - 17319), H = 5.17 mm; F. Paratype, Capraia Is., Italy, H = 5 mm (BA); G – H. Gorgona Is., Italy, H. 3 mm (IN); I. Banco di Santa Lucia, Italy, 440 m, juvenile (CS); J. Banco di Santa Lucia, Italy, 440 m, juvenile, H = 3.85 mm (CS).

FIGURE 28. A – L. Mitromorpha spp. Fist whorls (SEM). A. Mitromorpha columbellaria, Marina di Camerota, Italy (CS); B. Mitromorpha olivoidea, Lampedusa Is., Italy (MO); C. Mitromorpha karpathoensis, Salina Is., Italy (BA); D. Mitromorpha wilhelminae morph A, Alboran Is., Spain (CS); E. Mitromorpha wilhelminae morph B, Alboran Is., Spain (MO); F. Mitromorpha alyssae, holotype (MNHN); G. Mitromorpha bogii, paratype, Secca delle Vedove, Italy, 200 – 300 m, (MCZR, 00080); H. Mitromorpha cossyrae, holotype (MNHN); I. Mitromorpha mariottinii, holotype (MNHN); J. Mitromorpha mifsudi, olotipo (MNHN); K. Mitromorpha nofronii, holotype (MNHN); L. Mitromorpha tricolorata, holotype (MNHN). Scale bars: 100 µm.