Mitromorpha (Mitrolumna) tricolorata, 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 : 181-185

Mitromorpha (Mitrolumna) tricolorata n. sp.

( Figs 17 ; 26A–F; 27O; 28L)

Type material. Holotype Cala Calandra, Lampedusa Is., Central Mediterranean Sea, 30 m depth, 30.iv.1991 (H. 5.65 mm, W 2.9 mm), ( MNHN IM- 2000-27713) ( Fig. 26 A–C; 28L). Paratypes: type locality, 2 sh + 6 juv. (INC); 2 sh (BA); Capo Grecale, Lampedusa Is., 50 m, vii.2009, 2 sh (BA), 1 sh (CS), 1 sh (MO).

Type locality. Cala Calandra, Lampedusa Is., Central Mediterranean Sea, 30 m depth.

Other material examined. Italy: Capo Grecale, Lampedusa Is., 50 m, vii.2009, 2 sh (BA); type locality, 4 sh juv. (BA), 1 sh juv. (MO); Lampedusa Is., Punta Cappellone, Sicily, 4 sh (PC).

Etymology. After the chromatic pattern of the shell, with caramel, violet and white colors.

Distribution and habitat. Known so far only from the type locality, Lampedusa Is., Central Mediterranean Sea. Recent. Empty shells in bioclastic sands, from 30– 50 m. Found sympatric, often at different depths, with M. olivoidea , M. columbellaria and M. karpathoensis .

Description. (in parentheses the data of the holotype) Shell small for the genus ( Figs 26 A–F; 27O), height 5.6–6.15 (5.65 mm), width 2.75–2.95 (2.9 mm), solid, fusiform, biconic, slender, H/W=1.931–2.084 (1.948); a single, particularly slender specimen (Cala Calandra, Lampedusa Is.) with a H/ W 2.218. Protoconch paucispiral ( Fig. 28L ) shiny, slender, of 1.3–1.4 (1.4) convex whorl, d 0.20–0.225 (0.20 mm), Do 0.35–0.375 (0.35mm), DM 0.45–0.50 (0.50 mm), h 0.45 mm (0.45 mm), covered by large, densely arranged, subtriangular granules. Protoconch-teleoconch boundary well marked, slightly flexuose, opisthocline. Teleoconch of 4.4–5 (4.5) slightly convex whorls. Sculpture starting with 3–4 (3) spiral cordlets crossed by 13 (13) axial ribs on the first whorl, the abapical spiral more pronounced in the first two whorls, giving the spire a keeled outline. Additional spiral cordlets between the adapical ones and between the suprasutural one and the suture. Last whorl sculptured over the entire surface by 18–22 (18) strong spiral cordlets, flat, equidistant, of equal size, of which 4 (4) above the aperture and one partly masked by the suture. Axial ribs not present on the last 0.9 whorl. Two columellar folds, the posterior larger. Growth lines visible over the entire surface. Outer lip sharp, thickened internally with 7 (7) denticles, the second or third posterior larger. Anal sinus shallow. Siphonal canal short, and wide. Coloration caramel in the background, with subsutural and basal areas lighter, a whitish stripe always present on the adapical spiral cordlet, more evident on the lasts whorl. Protoconch neatly lighter than the rest of the shell, first teleoconch whorls and aperture violet. Soft parts unknown.

Remarks. M. tricolorata n. sp. is characterised by a peculiar chromatic pattern, and by the constant presence of a prominent abapical spiral cordlet, which gives the first whorls a keeled appearance. M. karpathoensis ( Figs 11 A–P; 16A; 27M) has fewer and larger nodules on the first whorls. M. columbellaria ( Figs 1–5 ; 27A–E) has a different chromatic pattern, being almost monochrome, with rare specimens bearing a differently colored subsutural band and the first whorls not keeled. M. mariottinii n. sp. has fewer spirals on the last whorl (14– 18 v. 18–22 in M. tricolorata ), a different outline with almost flat spire and a more blunt apex. M. mifsudi n. sp. has broader spirals with finer interspaces, and more robust columellar folds.

Table 1. Ranges of morphometric characters of the teleoconch in Mediterranean species of the genus Mitromorpha . Measurements in mm.

(ad): sample size (full grown intact adults); H: height; W: width; H/W; ratio height/width; Nw: number of whorls; Nrfw: number axial ribs on the first whorl; Nrpw: number axial ribs on the penultimate whorl; Nslw(aa): number of spirals on the last whorl (above the aperture); Nd: number of denticles; Sts: starting number of spiral cordlets. H, W (and H/W), Nw, Nrpw, Nslw, Nsuw(aa), Nd have been measured/counted only on fully grown adults.

exceptionally upt to 8 (see text); ** occasionally lacking (see text); *** up to 9 in the deep-water morph

Table 2. Morphometric characters of the protoconch in Mediterranean species of the genus Mitromorpha . Measurements in mm. N: sample size; h = height; d = diameter nucleus ; Do= diameter of first half whorl; DM = maximum diameter; npw = number of protoconch whorls; Ptb =Protoconch-teleoconch boundary.

Figures

FIGURE 1. Mitromorpha columbellaria (Scacchi, 1836). A-C. Scilla, Italy, 40 m, H = 6.75 mm (AR); D. Neotype of Mitromorpha algeriana (Pallary, 1900 ex Monterosato ms), Oran, Algeria, H = 5.75 mm (MNHN, IM- 2000 - 27714); E – F. Algeria, H = 7.25 mm (MCZR, M- 21 - 17319), labelled “ Mitromorpha algeriana v. cingulosa ” (Monterosato in schedis); G – I. Neotype of Mitra. columbellaria Scacchi, Capri Is., Italy, H = 6.95 mm (MCZR, M- 21 - 17319); J – K. Holotype of Mitromorpha mediterranea Mifsud, 2001, ‘ Méditerranée’, H = 5.4 mm, (IRSN-IG 3354); L – N. Lectotype of Mitromorpha leontocroma (Brusina, 1866), H = 6.9 mm (CNHM- 2088 c); O – P. Messina, Italy, harbour 30 – 50 m, juvenile with sketch of the living animal (by Danilo Scuderi).

FIGURE 2. Mitromorpha columbellaria (Scacchi, 1836). A – C. Mitromorpha granulosa (Locard, 1886) Porquerolles, France, H = 5 mm (coll. Locard, MNHN); D – E. Mitromorpha granulosa (BDD, 1884) Tunisia, not measured (coll. Dautzenberg, MNHN); F – I. Mitromorpha major (Locard, 1886) Porquerolles, France, H = 4.7 mm, 5 mm, 5.9 mm (coll. Locard, MNHN); J – K. Mitromorpha olivoidea (Cantraine, 1835), Roussillon, France, not measured, (coll. Dautzenberg, MNHN); L – O. Mitromorpha major (Locard, 1886) Toulon, France, H = 5.4 mm, 4.8 mm, 6.2 mm, (coll. Locard, MNHN).

FIGURE 3. Mitromorpha columbellaria (Scacchi, 1836). A – C, E. Salina Is., Italy, morph D, H = 6.6 mm (BA); D. Salina Is., Italy, morph D, juv. specimen; F, G. S. Vito lo Capo, Italy, morph D, H = 5.8 mm (MCZR, M- 21 - 17319); H, I. Provence, France, morph E, H = 6.05 mm, (coll. Monterosato ex Sollier, MCZR, M- 21 - 17319); J. Portopalo di Capo Passero, Italy, H = 4.45 mm (IN); K, L. Ragusa, Italy, H = 5.85 mm, (coll. Monterosato, ex Coen, ex Brusina, MCZR, M- 21 - 17319); M, N. var. major (BDD, 1883) (var. maxima Monterosato in schedis), Oran, Algeria, H = 9.5 mm (coll. Monterosato ex Pallary MCZR, M- 21 - 17319); O. locality unknown, white specimen, H = 8 mm (MCZR, M- 21 - 17319); P. Caprera Is., Italy, 20 m, white specimen, H = 6.05 mm, (CS); Q. Portopalo di Capo Passero, Italy, white specimen, H = 4.95 mm (IN); R. Palinuro 50 m, H = 6.8 mm (SB-MS).

FIGURE 4. Mitromorpha columbellaria (Scacchi, 1836). A – B. Levanzo Is., Italy, H = 6.25 mm (IN); C – D. La Maddalena Is., Italy, H = 7.05 mm (IN); E. ‘ GG 48 ’, H = 3.6 mm (MO); F, G. Marina di Camerota, Italy, H = 3.9 mm (CS); H. Cabo de Palos, Spain, H = 5.95 mm (IN); I. Marina di Camerota, Italy, 35 m, H = 6.4 mm (CS); J – K. Anzio, Italy, H = 3.25 mm (IN); L. Mitromorpha columbellaria drawn after Philippi (1844: 195, pl. XXVII, fig. 17).

FIGURE 5. Mitromorpha columbellaria (Scacchi, 1836), A – C. Lectotype of Mitromorpha leontocroma (Brusina, 1866), H = 6.9 mm, W 3.2 mm (CNHM, inv. n. 2088 c); D – F. Paralectotype of Mitromorpha leontocroma (Brusina, 1866), H = 6.3 mm, W 3.1 mm (CNHM inv. numb. 2088 a); G – I. Paralectotype of Mitromorpha leontocroma (Brusina, 1866), H = 6.9 mm, W 2.9 mm (CNHM inv. numb. 2088 d).

FIGURE 11. Mitromorpha karpathoensis (Nordsieck, 1969). A. Cape Palinuro, H = 6.3 mm (SB-MS); B. Salina Is., Italy, H = 6.6 mm (BA); C. Salina Is., Italy, juvenile, H = 3.2 mm (BA); D. Salina Is., Italy, close-up of the first whorls (BA); E. Ponza Is., Italy, juvenile, H = 2.1 mm (CS); F, G. Acitrezza, Italy, juvenile,? 80 – 100 m with a sketch of the living animal (by Danilo Scuderi); H. Cape Palinuro, Italy, 50 m, H = 8.8 mm (SB-MS); I. Cape Palinuro, Italy, 50 m, H = 6.35 mm (SB-MS); J, K. Gulf of Napoli, Italy, “ coralligenous bottoms ”, H = 5.5 mm, (MCZR, M- 21 - 17319); L. Cape Palinuro, Italy, 50 m, H = 6.6 mm (SB- MS); M. Vendicari, Italy, H = 5.9 mm (IN); N. Vendicari, Italy, close-up of the first whorls (IN); O – P. Cyprus, H = 5.55 mm, 6.15 mm (CS).

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 26. Mitromorpha tricolorata n. sp. A – C, F. Holotype, Lampedusa Is., Italy, H = 5.7 mm (MNHN, IM- 2000 - 27713); F. close-up of the first whorls, Lampedusa Is., Italy. D. Paratype, Lampedusa Is., Italy, H = 5.85 mm (BA); E. Lampedusa Is., Italy, H = 2.9 mm, juvenile.

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.