Sinezona singeri, Geiger, Daniel L., 2006

Geiger, Daniel L., 2006, Eight new species of Scissurellidae and Anatomidae (Mollusca: Gastropoda: Vetigastropoda) from around the world, with discussion of two new senior synonyms, Zootaxa 1128, pp. 1-33 : 19-22

Sinezona singeri new species: Figure 14–16

Type material. Holotype SBMNH 359439, ex DLG 101. Figure 14 A. Paratype SBMNH 359440, 1, ex DLG 101, from type locality. Figure 14 B.

Type locality. Intertidal, Blue Hole, Dahab, Janub Sina, Egypt, 28.483°N, 34.533°E. Leg. B. Singer Oct. 1990.

Etymology. Named for Benjamin (Solly) Singer, of Rehovot, Israel, the collector of the type material, for his continuing contributions to Red Sea malacology and in recognition of his service to the malacological community at large, particularly that of Israel.

Description. Shell mediums size (1.6 mm = holotype, paratype), trochiform depressed. Protoconch of 0.75 whorls, smooth, apertural varix connected to embryonic cap, apertural margin deeply sinusoid. Teleoconch I of approximately 1.125 whorls, 12–13 distinct axial cords, interstices filled with fine irregular axials, no spirals. Teleoconch II of 1.33 whorls. Shoulder slightly convex, approximately 23–26 fine axials opn first whorl, approximately half as strong as axials on teleoconch I, interstices with finest growth lines; approximately a dozen somewhat irregularly spaced fine spirals forming barely noticeable points at intersection with axials. Base with strong constriction below selenizone, then inflated; 21–26 axials starting as thin thread on keels of selenizone, becoming strong elevated costae at periphery, thinning out to threads towards transition to umbilicus; approximately 20 finer spirals, becoming stronger from selenizone towards umbilicus, running over axials; no keels. Umbilicus open, wide, bordered by spiral cord towards base, walls smooth. Selenizone above periphery, keels moderately elevated, moderately strong, strong growth lamellae; foramen narrow treadrop­shaped, extending approximately 0.16 whorl. Aperture rounded, roof strongly overhanging.

Radula rhipidoglossate. Rachidian tooth triangular, seven denticles on cusp, central one largest, parallel to radular ribbon. Lateral teeth 1–3 similar, three denticles on outer margin. Lateral tooth 4 reduced, hook shaped, with three minute points at cusp. Lateral tooth 5 broadened enlarged, approximately five denticles on inner margin. Radular interlock of central field moderate. Inner marginal teeth with spoon shaped cusp with three to four denticles on each side; outer marginals spoon shaped, with many fine denticles on cusp.

Differential diagnosis. Sukashitrochus dorbignyi (Audouin, 1826) and Suk. tricarinatus (Yaron, 1983) from the Red Sea share the closed foramen, but show distinct spiral keels on the base. Scissurella rota Yaron, 1983 from the Red Sea has an open slit, fewer spirals on the base that form pronounced hollow points at the intersection whith the axials, and has a protoconch with fine axial sculpture. Scissurella reticulata Philippi, 1853 and Sci. sudanica Bandel, 1998 have an open slit, a less pronounced constriction below the selenizone, and a protoconch with fine axial sculpture. The species is superficially most similar to Sci. hoernesi Semper, 1865 from the Indo­Malayan Archipelago, which however has an open slit and stronger axial sculpture on the shoulder that maintains its strength on teleoconch I and II.

Distribution. Red Sea to Mascarene Islands, western Indian Ocean.

Specimen records. 0–3 m, Baye de Ranobe, near Mora Mora, N of Tulear, Toliara Province, Madagascar, 23.083°S, 43.500°E (LACM 89–50, 1). Mayotte, E. reef Bandele, France, 12.902°S, 45.252°E (MNHN, 4). 520–830 m, Mayotte, E. Bandele reef, France, 12.897°S, 45.270°E (MNHN, 1). 1300–1480 m, Mayotte, E. Bandele reef, France, 12.933°S, 45.300°E (MNHN, 1). 500 m, Mayotte, E Bandele reef, France, 12.895°S, 45.268°E (MNHN, 3). 1300–1480 m, Mayotte, E Bandele reef, France, 12.933°S, 45.303°E (MNHN, 1). 330–530 m, Glorieuses, N. Ile du Lys, 11.440°S, 47.372°E (MNHN, 1). 170–225 m, Reunion Island, 21.083°S, 55.200°E (MNHN, 4; MNHN, 2).

Figures

FIGURE 14. Sinezona singeri new species A. Holotype (SBMNH 359439). B. Paratype (SBMNH 359440). A­B. Blue Hole, Dahab, Janub Sina, Egypt, 28.483 ° N, 34.533 ° E. C. LACM 89 ­ 50. 0 ­ 3 m, Baye de Ranobe, near Mora Mora, N of Tulear, Toliara Province, Madagascar, 23.083 ° S, 43.500 ° E Specimen used for radula extraction. Scale bars shells = 500 µm. Scale bars protoconch = 100 µm.

FIGURE 15. Paratypes of Sinezona singeri new species. A. 170 ­ 225 m, Reunion Island, 21.083 ° S, 55.200 ° E (MNHN). B. 1300 ­ 1480 m, Mayotte, E Bandele Reef, France, 12.933 ° S, 45.303 ° E (MNHN). 200 ­ 500 m, Mayotte, E. Bandele Reef, France, 12.902 ° S, 45.252 ° E (MNHN). Scale bars shell = 1 mm. Scale bars protoconch = 100 µm.

FIGURE 16. Radula of Sinezona singeri new species. From LACM 89 ­ 50. 0 ­ 3 m, Baye de Ranobe, near Mora Mora, N of Tulear, Toliara Province, Madagascar, 23.083 ° S, 43.500 ° E shown in Figure 14 C. A. Anterior half of radular ribbon. Scale bar = 100 µm. B. Posterior half of radula ribbon. Scale bar = 100 µm. C. Full width of radula. Scale bar = 50 µm. D. Outer marginal teeth. Scale bar = 10 µm.