Aulacofusus tanagaensis, Mclean & Clark, 2023

Mclean, James H. & Clark, Roger N., 2023, Seven new genera and thirty-four new species of buccinoid gastropods (Neogastropoda: Buccinidae) from the Aleutian Islands, Alaska, Zootaxa 5351 (2), pp. 151-201 : 175

Aulacofusus tanagaensis n. sp.

Figures 14 E–G urn:lsid:zoobank.org:act:E0B6338B-A0F0-4352-B53D-0AD9871C3DFE

Type locality: South end of Kanaga Pass, Andreanof Ids., Aleutian Is., Alaska (51°40.0 N, 177°51.21 W), 53 m. ( NMFS 95-199401 - 117 ) .

Type material: Holotype LACM 3665 , 54.9 mm. (leg. William C. Flerx, 4 July, 1994, trawled, R/ V Pacific Knight) ; Paratypes: Pt 1, LACM 3666 , 41.5 mm. W of Tanaga Island, Andreanof Ids. (51°44.5 N, 178°07.68 W), 95 m. ( NMFS 23-199701 - 137 ); Pt 2 & 3, SBMNH 169004 , 43.0– 43.5 mm. W of Tanaga Island, Andreanof Ids. (51°44.5 N, 178°07.68 W), 95 m. ( NMFS 23-199701 - 137 ); Pts 4 & 5 RNC 4585 , 44.8 – 54.0 mm. W of Tanaga Island , Andreanof Ids. (51°44.5 N, 178°07.68 W), 95 m. ( NMFS 23-199701 - 137 ) .

Referred material: 1, RNC 4859 , 35.3 mm. S of Amlia Island , Andreanof Ids. (51°55.32N, 173°40.44 W), 117 m. ( NMFS 176-201401 - 62 ); 1 , RNC 4350 , 56.7 mm. N of Seguam Island (52°33.99 N, 172°24.25 W), 211 m. ( NMFS 148-201001 - 78 ) .

Description: Shell of medium size (holotype 54.9 mm), elongated fusiform, with rounded whorls; color white; periostracum thin, yellow. Protoconch with 2.5 whorls; teleconch with six to six and a half whorls, early whorls with 11 cords, penultimate whorl with 15–17 low rounded spiral cords; base with 17–20 additional cords. Aperture about 1/3 of shell height, canal constricted, relatively long.

Radula: Typical for genus, Rachidian tooth excavated anteriorly, tri-cuspid, the three cusps set close together; central cusp slightly longer than the outer ones. Lateral teeth tricuspid, outer cusp long, slender, curved, central cusp much smaller, slightly curved, and slenderer, set close to inner one; inner cusp thick, curved, about 2/3 as long as outer one.

Remarks: Aulacofusus tanagaensis resembles Aulacofusus esychus (Dall, 1907) , but differs in 1) Rounded as opposed to rather flattened whorls, and 2) more prominent spiral sculpture. It also resembles Aulacofusus brevicauda kurilensis Golikov & Gulbin, 1977 , from the Kurile Islands, Russia, but differs in 1) much thinner shell, and 2) finer and more numerous spiral cords 15–17, as opposed to 10–12 in the former species.

Etymology: Named for Tanaga Island, where the fist specimens were collected.

Distribution: Occurs in the Andreanof Ids., central Aleutian Is., from Seguam Island (172°24 W) to West of Tanaga Island (178°07 W), at depths of 53– 211 m.

Habitat: On volcanic sand and gravel bottoms, at temperatures of 3.7°– 4.8°C.

Figures

FIGURE 14. A–D. Aulacofusus canaliculatus n. sp. A. Holotype, LACM 3667, SE of Agattu Island, 135 m, 66.6 mm; B. Paratype, RNC 4143, S of Buldir Island, 71 m, 53.3 mm; C. Aulacofusus periscelidus (Dall, 1891), RNC 4860, W of Hawadax (Rat) Island, 94 m, 77.47 mm; D. RNC 4625, Adak Island, 18 m, 69.1 mm; E–G. Aulacofusus tanagaensis n. sp.; E. Holotype, LACM 3665, W of Tanaga Island, 53 m, 54.9 mm; F. Paratype, RNC 4585, W of Tanaga Island, 95 m, 54.0 mm; G. Radula, paratype, bar = 200 µm.