Turris ruthae Kilburn, 1983

Kilburn, Richard N., Fedosov, Alexander E. & Olivera, Baldomero M., 2012, Revision of the genus Turris Batsch, 1789 (Gastropoda: Conoidea: Turridae) with the description of six new species, Zootaxa 3244 (1), pp. 1-58 : 43-44

Turris ruthae Kilburn, 1983

Plate 26 , figs A–C

Turris ruthae Kilburn, 1983: 558 , figs 1 (protoconch), 12 (radula), 22–23. Type loc.: off Port Grosvenor, Transkei, South Africa, 80 m, on a bottom of calcareous nodules and lithothamnion sheets.

DESCRIPTION: Medium-sized, b/l 0.32–0.33; aperture much shorter than spire (a/l 0.37–0.39), spire somewhat cyrtoconoid (initially orthoconoid), suture shallow, not channelled, whorls with projecting, rounded peripheral angle; anal sinus deep with slightly constricted opening.

Spiral cords rounded, without sharp edges. Subsutural cord ill-defined (forming a weak ridge on early whorls), sulcus broad and gently concave, sinus cord with low, lunulate crenules; base of each whorl with a single rounded cord, showing at periphery of last whorl; base of last whorl with 3 rounded, weakly nodose cords, weakening anteriorly, subequal in width to their intervals; rest of base and rostrum with 10–12 anteriorly weakening spiral ridges, obsolete on base, sometimes with irregular intermediary threads. Spiral cords incised by growth lines, of which intermittent ones form weak, rounded nodules. Microscopic spiral threads overall, most distinct below suture.

Protoconch blunt (protoconch I fairly large), of 2 whorls, maximum diameter 1.4–1.6 mm, smooth, with terminal growth lines only.

Cream-colour, sometimes with diffuse brown spots, periostracum not obvious.

Attains 45 mm.

DISTRIBUTION: South-east Africa, on outer continental shelf and upper slope of southern Natal and Transkei, from Scottburgh to near East London, 70–150 m, mainly on coarse sand and sponge bottoms.

TYPES: Holotype NMSA C1801 , paratypes in NMSA, SAMC, NHMUK, USNM, ANSP .

OTHER MATERIAL EXAMINED (all NMSA, dredged RK et al., paratype data cited by Kilburn (1983) not repeated here): NATAL: S.E. of Illovo Beach, 90 m, fine sand (D4090) ; off Park Rynie, 96 m, live sponges (B8560) ; off Kwanyana River, 100 m, sponge rubble (C5316) ; off Port Edward, 120–128 m, live sponges (D1378), TRANSKEI: between Mtamvuna and Mzamba Rivers, 100 m, large living sponges, rubble (C5400) ; off Mzamba River, 100 m, sponge rubble (C5261) ; off Mpahlana River, 100 m, sponge rubble (C5232) ; off Mncwasa Point, 74 m, sand and rubble (C2204) ; off Whale Rock, 72–78 m, loose rocks, sand, shell debris (C3130) ; off Whale Rock, 90 m, sponge rubble, coarse sand, some rocks (C9474). EASTERN CAPE: off Nahoon, 85 m, medium sand, broken shell (C8254) ; off Kidd’s Beach, 90 m, coarse sand, sponge (B8250) ; off East London, 90 m, coarse sand (B7996) ; do, coarse sand, sponges, gorgonians, living (B7817) .

REMARKS: Turris ruthae somewhat resembles T. ambages , but has much more angular whorls, a less abbreviated base, more rounded spiral cords with wider intervals, a wide, evenly concave (instead of narrowly channelled) sulcus, and a less distinctly differentiated subsutural cord; the protoconch, too, differs in size and in other respects.

The shape of the marginal teeth of the radula is unique within Turris (see Kilburn (1983)), and may indicate the species to belong to a distinct genus.

Figures

PLATE 26. Turris ruthae Kilburn, 1983: A, B—Holotype, 80 m, off Port Grosvenor, Transkei, South Africa, NMSA C1801, 44.6 x 14.4 mm; C—Off East London, 100 m, coarse sand, NMSA B8110, 47.7 x 15.6 mm