Buccinum bizikovi Kantor & Sirenko & Zvonareva & Fedosov 2022, sp. nov.

Buccinum bizikovi sp. nov.

urn:lsid:zoobank.org:act: A6137049-7001-4443-AFF1-044DE0E0D832

Figs 5, 6D–F

Buccinum (Buccinum) bombycinum – Golikov 1980: 327, figs 85, 183, 391, 1 pl. XXXI, 1a–1k (part.) (non Dall 1907).

Bathybuccinum (Ovulatibuccinum) ovulum – Golikov & Sirenko 1988: 93, figs 13–15 (non Dall, 1895).

Bathybuccinum ovulum – Golikov & Sirenko 1998: 122, fig. 12c; Kantor & Sysoev 2006: 160, pl. 74i (non Dall, 1895).

Bathybuccinum bombycinum – Kantor & Sysoev 2006: pl. 74d (non Dall 1907).

Bathybuccinum sp. 2 — Sirenko et al. 2013:159.

Diagnosis

Shell reaching 29.5 mm in length, thin, broadly oval, smooth except inconspicuous, irregularly spaced, sometimes oblique spiral cords. Axial sculpture only of thin growth lines. Operculum thin, small, less than 1/ 5 of AL, brown, with terminal nucleus notably shifted to lower outer operculum edge.

Etymology

Named in honour of Vyacheslav Bizikov, Soviet and Russian malacologist, who collected deep-water gastropods, including this species, near the Kurile Islands.

Type material

Holotype KURILE ISLANDS • lv; Iturup I., 44°20.8′ N, 148°24.0′ E; depth 414 m; Kurile-Sakhalin Expedition, F/T Toporok, stn 101; 14 Sep. 1949; ZIN 62781.

Paratypes KURILE ISLANDS • 4 lv; same collection data as for holotype; ZIN 62782.

Other material examined

KURILE ISLANDS • 1 lv (SL 19.1 mm); Shikotan I.; 44°08.1′ N, 147°57.0′ E; depth 285–286 m; Kurile-Sakhalin Expedition, F/T Toporok, stn 93; 13 Sep. 1949; ZIN 62788 • 1 lv (SL 16.9 mm); Iturup I.; 44°58.2′ N, 149°19.0′ E; depth 605–620 m; R/V Odyssey; 25 Jul. 1984; ZIN 48103 • 1 lv (SL 18.0 mm); Simushir I.; depth 450–480 m; R/V Odyssey; 30 Dec. 1984; ZIN 62787 • 1 lv (SL 29.5 mm); Polonskogo I.; 43°19′ N, 146°37′ E; depth 500 m; R/V Tikhookeanskiy, stn 10, sample 26; 9 Jul. 1987; ZIN 62785 • 1 lv (SL 14.0 mm); Shikotan I.; 43°37′ N, 147°19′ E; depth 400 m; R/V Tikhookeanskiy; 11 Jul. 1987; ZIN 62783 • 1 lv (SL 18.0 mm); Iturup I.; 44°49.5′ N, 149°01.7′ E; depth 650 m; R/V Tikhookeanskiy; 13.08.1987; ZIN 62786.

SEA OF OKHOTSK • 3 lv (SL 15.0– 23.1 mm); South-eastern Sakhalin, 47°50.4′ N, 142°53.5′ E; depth 78 m; Kurile-Sakhalin Expedition; F/T Toporok; stn 145; 30 Sep.–1 Oct. 1949; ZIN 62783.

Description

MEASUREMENTS (holotype). SL 20.0 mm, AL 13.6 mm, SW 13.1 mm. Largest available specimen attains 29.5 mm.

SHELL. Thin, fragile, oval, smooth, with short siphonal canal, pale-brownish to rose- brownish. Protoconch of about 1.5 low, convex whorls, strongly eroded. Teleoconch whorls 3+, suture distinct, adpressed at periphery of previous whorl. SW/SL ratio 0.62–0.67 (0.65 in holotype), LW/SL ratio 0.80–0.81 (0.80 in holotype). Axial sculpture of thin, weakly prosocline growth lines. Spiral sculpture of low, indistinct irregularly spaced, sometimes oblique cords.Aperture large, semi-oval. Outer lip thin, slightly adpressed adapically. Columella straight, smooth. Siphonal notch wide and rather shallow. AL/SL ratio 0.64–0.70 (0.68 in holotype). Periostracum thin, smooth, yellowish brown. Operculum (Fig. 6E) small, spanning less than 0.25 of AL, thin, brownish, translucent, oval, with nucleus shifted to lower edge,.

RADULA (n = 1). Rachidian tooth with broad rectangular basal plate and five short cusps nearly equal in length. Lateral tooth with three cusps, outer cusp longest, intermediate shortest and most narrow (Fig. 6D).

PENIS (n = 1). Distal end of the penis with cone-shaped papilla, surrounded by circular fold (Fig. 6F).

Remarks

Specimens of this new species were previously identified as Buccinum bombycinum (Golikov 1980) or Bathybuccinum ovulum (Golikov & Sirenko 1988, 1998). Kantor & Sysoev (2006) suggested that the specimens, identified by Golikov & Sirenko are not conspecific with B. ovulum.

The new species differs from B. ovulum (Fig. 5G) in having a higher spire (LW/SL ratio is 0.92 in B. ovulum vs 0.80–0.81 in B. bizikovi) and a smaller operculum (less than 0.25 of AL in B. bizikovi and typically around 0.4 in B. ovulum) with nucleus situated much closer to the edge. The new species differs from B. hasegawai in having a broader shell (SW/SL ratio 0.48–0.58 in B. hasegawai and 0.62–0.67 in B. bizikovi) and a lower aperture (AL/SL ratio 0.51–0.63 in B. hasegawai and 0.64–0.70 in B. bizikovi). Buccinum ovulum sensu Golikov & Sirenko 1988 (non Dall 1907) was designated as the type species of Bathybuccinum (Ovulatibuccinum). Therefore, it is a case of misidentified type species and it is now fixed (under Article 70.3 of the Code) as Buccinum bizikovi sp. nov. misidentified as Buccinum ovulum Dall, 1907 in the original designation by Golikov & Sirenko (1988).

Distribution

Kurile Islands: Simushir, Iturup, Shikotan and Polonskogo Islands, depth 285–650 m; Okhotsk Sea, south-eastern Sakhalin, depth 78 m.