Turris nadaensis Azuma, 1973

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 : 37-39

Turris nadaensis Azuma, 1973

Plate 22 , figs A–I

Turris nadaensis Azuma, 1973: 33 , figs 6–7 (radula); Higo, Callomon & Goto 1999: 303; Olivera 2000: 309, pl, 1, specimen 10, pl. 8; Hasegawa et al. 2000: 633, pl., 315, fig. 64; Olivera & Sysoev 2008: pl. 681, figs 2–4; Robin 2008: pl. 449, fig. 2. Type loc.: off Nada, Kii Peninsula, Japan, 20–30 fath. [37–55 m].

Turris undosa (non Lamarck, 1816); Robin 2008: pl. 449, fig. 2.

? Turris undosa ; Vera-Peláez et al. (2000): pl. 1, fig. 2 (protoconch), pl. 4, figs 4–6.

DESCRIPTION: Shell very variable in proportions and in length of siphonal canal, b/l 0.27–0.32, a/l 0.28–0.42. Suture shallow. Sculptured by sharp spiral cords, with rather wide intervals, bearing fine collabral threads. Subsutural cord low (in fact distinctly impressed), bearing a sharp median ridge with a weak one on either side. Sulcus moderately deep, and recessed under sinus cord, bordered by delicate, oblique scales (instead of a thin lamellate flange as in T. undosa ). Sinus cord angular and shouldered (i.e. sloping) towards lip becoming flattened and with two thin ridges. Peripheral cord angular and moderately prominent, separated from sinus cord by a delicate, minute interstitial flange bearing oblique scales. Base of spire whorls with two angular ridges with widely sloping sides, intervals sometimes one or more spiral threads. Base of last whorl with a total of 17–20 spiral ridges, the upper 5–6 the strongest, becoming gradually weaker anteriorly (with a few finer intermediary threads), 5–6 uniformly fine ones on base of rostrum.

White or brownish-white, with oblique axial stripes, breaking into spots on base of last whorl, crests of main ridges often with a thin brown line; inner lip and base of last whorl tinged with violet.

Protoconch small, conical, ca 2.5 whorls, all except 1st with arcuate axial riblets.

Attains 87.5 mm.

DISTRIBUTION: Southern Japan and Vietnam to the Philippines, Thailand and Solomon Islands, 10–150 m, sand.

TYPES: T. nadaensis : Holotype in private collection of late Masao Azuma, no. 16151, present location not traced.

OTHER MATERIAL EXAMINED: JAPAN: Tanabe Bay, Honshu, Japan ( ANSP 421607 and 420647). VIETNAM: off Nha Trang, 70 m, sand ( NMSA L7994: N. Thach). THAILAND: Racha Is., Phuket area, 20 m ( NMSA: S. Patamakanthin); S.W. of Phuket, ca 100–120 m, trawled ( NMSA L3588: S. Patamakanthin). PHILIPPINES: Balut Is., tangle net in ca 150 m; Masbate Is., 10–20 m, and Aliguay Is, Mindanao, trawled in 80–150 m (Guido Poppe colln); Matanos, Samal Is. Davao Gulf; Olango and Palawan Is. (BO colln); Panglao, Bohol, 73–110 m ( NMSA L1855: D. Steinke); West Samar ( NMSA G6252: F. J. Dayrit); Palawan, tangle net ( NMSA J3949: F. J. Springsteen); SOLOMON IS: 9°50.4’S, 160°53.2’E, 82-83m ( MNHN)

REMARKS: Turris nadaensis is often confused with T. cristata , but is easily distinguished by its weak subsutural cord, much more uniform spirals and non-contracted base. Olivera (2000) discussed variation in T. undosa (as T. nadaensis ) and noted the occurrence of a form with a stronger, sharper peripheral cord, rendering the whorls more angular; this form would appear to be typical undata. However, available material of T. nadaensis appears to show variation that is not easy to interpret. Variability in length of siphonal canal and in its degree of tapering is obvious, as is colour of base (vivid violet to pinkish-white). But size also varies: adult Philippine examples are usually 67.0 to 76.0 mm in length, Vietnamese specimens are particularly large (to 87.5 mm) but Thai adults may not exceed 46 mm. One Vietnamese specimen (NMSA L7994) has a particularly short, recurved siphonal canal. Variation in angularity of spiral cords may be visually exaggerated by a distinct spiral line on their crests.

Figures

PLATE 22. Turris nadaensis Azuma, 1973: A—Holotype, off Nada, Kii Peninsula, Japan, 45–65 m, in late Masao Azuma colln (not traced), 83.2 x 22.5 mm; B—Tanabe Bay, Honshu, Japan, ANSP 421607, 62.1 x 20.3 mm; C, D—Tanabe Bay, Honshu, Japan, ANSP 420647: C—87.4 x 26.6 mm; D—86.1 x 25.7 mm; E—Olango Is., Philippines, BO colln, 67.5 x 18.0 mm,; F, G—off Nha Trang, Vietnam, 20–70 m, NMSA L7994, 86.6 x 24.7 mm; H, I—Palawan Is., Philippines, BO colln, 65.2 x 18.6 mm.