Castaneobuccinum lauthi Mclean & Clark 2023, n. sp.

Castaneobuccinum lauthi n. sp.

Figures: 21 D–F

urn:lsid:zoobank.org:act: 10A35EEE-3C55-4146-A37D-54FE5706AD4C

Type locality: Petrel Bank, N of Semisopochnoi Island, Rat Ids., Aleutian Is., Alaska (51°53.53 N, 179°44.6 E) (Rae Baxter 86–235), 121 m.

Type material: Holotype, LACM 3591 (leg. Rae Baxter, 30 August, 1986); Height 76.4 mm; Paratypes: Pt 1, SBMNH 169020, 76.7 mm. Petrel Bank, rat Ids. (51°54.57 N, 179°45.58 E), 87 m. (NMFS 148-201001 - 134); Pt 2, RNC 4011, 71.6 mm. Petrel Bank, Rat Ids. (52°09.58 N, 179°42.62 E), 94 m. (NMFS 94-1994 - 153).

Referred material: 3, RNC 4024, 58.8–67.1 mm. Petrel Bank, Rat Ids. (52°04.15 N, 179°41.34 E), 74 m. (NMFS143-201001 - 146); 2, RNC 4157, 42.2–51.8 mm. S of Herbert Island, Islands of Four Mountains (52°32.6 N, 170°05.37 W), 237 m. (NMFS 57-200201 - 46); 1, RNC 4117, 69.4 mm. S of Buldir Island (51°57.8 N, 176°01.7 E), 71 m. (NMFS 23-200001 - 226).

Description: Shell relatively large (to 76 mm, SBMNH 169020), sturdy, tall spired; chestnut brown. Protoconch with two whorls; teleconch with six to seven whorls, early teleconch with 2–3 ribs; suture well impressed. Axial sculpture of sinuous, narrow undulations on shoulder, and forming broad nodes on major cords. Spiral sculpture of broad, strongly projecting cords, to three or four above the suture and four to eight on the base of the whorl; entire surface with finely incised spiral striations of slightly irregular spacing and not as deeply incised where positioned on major spiral cords. Aperture large, oval, a little more than 1/3 of shell height; outer lip inflated, forming broad, shallow sinus on upper part of whorl; lip edge strongly reinforced.

Radula: Rachidian tooth broad, subquadrate, excavated anteriorly and bearing six sub-equal cusps arranged in three divergent pairs; Lateral teeth large, tricuspid, outer cusp large, curved, pointed, central cusp much shorter, slender, sharply pointed, inner cusp blade-like, about three times as broad central cusp.

Remarks: The three or four spiral cords on the spire separate this species from its congeners.

Etymology: The name honors Robert R. Lauth, Fisheries Biologist, NOAA/NMFS [Alaska Fisheries Science Center (retired)].

Distribution: Central Aleutians, from Petrel Bank, N of Semisopochnoi Island (179° W) to vicinity of Buldir Island (176°E), at depths of 71– 95 m.

Habitat: Found on sand and gravel bottoms, at temperatures of 4.1–5.1°C.