Turris annulata
Creators: name: Kilburn, Richard N.
name: Fedosov, Alexander E.
name: Olivera, Baldomero M.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Turridae
Turris
Turris annulata

description: Turris annulata (Reeve, 1843)
Plate 4, figs A–J
Pleurotoma annulata Reeve, 1843: pl. 5, sp. 35. Type loc.: unknown.
Turris annulata (in part); Powell 1964: 333, pl. 254, figs 5–6 (copy of type figures of P. fagina), not pl. 181, fig. 19 [= T. kathiewayae sp. nov.].
Turris (Annulaturris) annulata; Powell 1966: 51; Horikoshi 1989: 32, fig. 1.
Annulaturris annulata; Dharma 2005: pl. 41, fig. 11.
Pleurotoma fagina Adams & Reeve, 1850: 40, pl. 9, figs 2a–b. Type loc.: China Sea.
Turris (Tomopleura) fagina; Melvill 1917: 146.
Turris fagina; Oostingh 1938: 27 (Pliocene of Java); Yen 1942: 238, pl. 25, fig. 184.
Pleurotoma (Pleurotoma) fabagina [sic] Weinkauff, 1877: 4.
DESCRIPTION: Shell fusiform with an acuminate, orthoconoid spire; spire angle 20–25º; b/l 0.23–0.29, a/l 0.41–0.45; base of last whorl somewhat constricted, siphonal canal slightly bent to right, longer than rest of aperture, narrow in young examples, in old individuals broad with a strong fasciole and deep false umbilicus; suture fairly shallow but sharply incised. Anal sinus relatively shallow, linguiform, margins with a slight flange.
Early whorls with three spiral cords, increasing to a total of 4 main cords on later whorls. Subsutural cord low and rounded, bearing an angular median ridge and a more or less weaker thread on either side. Sulcus a deep, narrow furrow, slightly recessed under sinus cord complex, edged anteriorly by an angular thread. Sinus cord at periphery, slightly projecting (sometimes beyond peripheral cord), weakly flat-topped with sloping sides, the posterior side slightly tabulate. Base of later spire whorls with two close-set spiral cords with sloping sides, whose edges each bear a thin spiral thread, upper cord nearly as strong as sinus cord, the intervals containing a few fine to strong spiral threads. Upper base of last whorl with three angular spiral cords, followed by weaker but uneven ridges, and groups of intermediary threads, those on rostrum alternately weaker and stronger. Collabral threads coarse but not pliculate, somewhat cancellating the finer threads.
Protoconch unknown.
Reddish-brown with main cords and rostrum paler; periostracum dull medium brown, smooth, covering cords when fresh.
Attains 96.4 mm in length.
DISTRIBUTION: Gulf of Oman and west coast of India to west coast of Thailand and Indonesia, in 10– 84 m.
TYPES: P. annulata: types lost (see discussion below). P. fagina: holotype NHMUK 1970095, dimensions 73.8 x 27.2 mm: this is here designated as the neotype of P. a n n u l a t a.
OTHER MATERIAL EXAMINED: ARABIAN GULF: Henjam Is., Iran (26º39’N; 55º52’E), 46 fath. [84 m], sand (NHMUK: Sykes colln). WEST THAILAND: Ko Racha Yai, south of Phuket Is. (7º36’N; 98º22’E), ca 20 m (NMSA L5609: S. Patamakanthin); Phuket Is., 3 mi NE. of Lighthouse Is., 80 ft [24 m] (ANSP 286281: International Indian Ocean Expedition). INDONESIA: Sunda Strait (105°40’E; 6°5.5’S), 52 m, juvenile (ZMUC, Mortensen). INDIA: 10 mi W, of Cochin, Kerala, 10–15 fath. [18–27 m] (ANSP 303824: R. Robertson); S. of Dwarka, Gujarat, 60–65 m (MCZH 362501).
OTHER RECORDS: Bintan Is., Sumatra (Dharma 2005)
REMARKS: Subsequent authors have synonymised Turris fagina with Turris annulata, and the dorsal view of Reeve’s figure of the latter does appear to agree with that of the holotype of T. fagina. Possible confusion has been caused by Powell’s suggestion that the missing type of T. annulata is “almost certainly” an unlocalised shell in the MacAndrew collection in NMWC (1955.158.00902). But there is no documented link between it and the Stainforth collection (where the holotype was held); furthermore, it shows a paler sinus cord than illustrated in Reeve’s figure, and has a last whorl that is not strongly concave below the suture; furthermore it bears an operculum, rarely preserved in Reeve’s era.
Turris annulata appears to vary somewhat in proportions. The more typical Thai population appears to comprise markedly narrower individuals than that represented by the holotype of P. f a g i n a; in this the area between the suture and the shoulder varies from flat to distinctly concave. A sample from Phuket (ANSP 286281) at first sight appeared to be somewhat intermediate between T. annulata and T. kathiewayae. However closer examination showed that bleaching and wear had produced a kathiewayae -like appearance, and sculptural details are those of T. annulata.
It may be noted that the term “ China Seas”, as used by Adams & Reeve, frequently included the seas of the Indo-Malaysian archipelago.
description: Published as part of 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, pp. 1-58 in Zootaxa 3244 (1) on pages 8-10, DOI: 10.11646/zootaxa.3244.1.1, http://zenodo.org/record/246329