Beringius nearensis Mclean & Clark 2023, n. sp.

Beringius nearensis n. sp.

Figures 7 A–D urn:lsid:zoobank.org:act: 1AD87361-3122-4D3B-9452-7DC578B193E6

Type locality: Stalemate Bank, W of Attu Island, Near Ids., Aleutian Is., Alaska (54°54.50 N, 170°49.26 E), 219 m (NMFS 23-199701 - 211).

Type material. Holotype LACM 3571, 103.4 mm. (leg. RNC, 3 August, 1997, trawled, R/V Dominator) Paratypes: Pt 1, USNM 1606662, 127.19 mm. E of Agattu Island, Near Ids. (52°28.04 N, 174°13.71 E), 118 m (NMFS 94-200201 - 161); Pt 2, SBMNH 169001, 119.7 mm. S of Shemya Island, Semichi Ids. (52°35.22 N, 174°17.79 E), 96 m (NMFS 148-201001 - 183); Pt 3, CASIZ 236197, 87.2 mm. E of Agattu Island, Near Ids. (52°10.89 N, 173°40.63 E), 163 m (NMFS 148-201001 - 188); Pt 4, RNC 4882, E of Agattu Island, Near Ids. (52°30.25 N, 174°13.41 W), 111 m (NMFS 147-200401 - 201).

Description: Shell of moderate size (to 127 mm, USNM 1606662), pyriform, white or pale pinkish, periostracum thin, brown, adherent; suture deeply impressed. Protoconch with 2.5 whorls; teleconch of 4–4.5 whorls. Axial sculpture of nine or ten projecting, often opisthocline ribs or folds, interspaces broader than ribs, persisting in final whorl. Spiral sculpture of seven to nine cords low, moderately strong, flat-topped or slightly concave cords topped by two to five fine threads; interspaces broader than cords, bearing similar fine threads. Aperture oval, much less than half of shell height, canal short, rather narrow.

Radula (fig. 7 D), rachidian tooth reduced, flat, plate-like, broader than long, lateral edges rounded, excavated anteriorly and posteriorly. Lateral teeth large, tri-cuspid, outer cusp very long, thick, curved, tapering, distally pointed, central and inner cusps much smaller, about ¼ as long as outer one, separated by a deep notch; inner cusp slightly shorter than central one, anteriorly flattened, and slightly curved.

Remarks: This species differs from Beringius undatus Dall, 1919 (figs. 7 E–F) by the profuse, spiral micro-striae on the cords and interspaces, the fewer nine to ten opposed to 12–14, less pronounced spiral cords and interspaces, and the lateral teeth of the radula, which in B. nearensis are broader and thicker, and have pronounced central and inner cusps separated from the outer cusp by a deep notch. Those of B. undatus (figs. 7E–F) are not separated by a deep notch. This might be considered only a variant of B. undatus, but for the great distance (1400 km) between distributions of the two species, between which no similar forms have been found. Beringius crebricostatus (Dall, 1877) (figs. 7 G–H) is also similar but differs in having strong spiral cords separated by deep, broad channels, and lacks axial sculpture. It might also be confused with some of the forms of Beringius kennicottii (Dall, 1871) (figs. 8A–H), but differs in the more prominent and regular spiral sculpture.

Etymology: Name refers to the Near Island group, at the extreme western end of the Aleutian.

Distribution: Western Aleutian Islands, apparently restricted to the vicinity of the Near Islands and Stalemate Bank, between 170°50’ E to 174°15 E.

Habitat: Found on combination rock/sand bottoms, at depths of 96–163 m, and a temperature of 3–4°C.