Frigidoalvania tanseimaruae Hasegawa, 2014

Hasegawa, Kazunori, 2022, Bathyal Rissoidae (Gastropoda: Rissooidea) off the Russian Far East coast of the Sea of Japan, with redescription of Punctulum reticulatum Golikov, 1986, Ruthenica, Russian Malacological Journal 32 (2), pp. 85-92 : 88

Frigidoalvania tanseimaruae Hasegawa, 2014

( Fig. 2 E–F )

Frigidoalvania tanseimaruae Hasegawa, 2014: 93–97 , figs 4 G–K, 6 E–F, 10–13, 49B; table 5.

Material examined. SoJaBio B 6-6, MIBM 39347; SoJaBio B 6-7; SoJaBio B 7-7 [depth range: 470–1011 m]

Additional material examined (cited from Hasegawa, 2014). IORAN, non-registered, R/ V Vityaz st. 6649, Peter the Great Bay, 42°37.4’N, 134°19.2’E –42°37.8’N, 134°18.5’E, 1186– 1130 m .

Distribution. Off Primorsky Krai coast on the northern slope, and from off southwestern Hokkaido to off Oki Island on the southeastern slope in the Sea of Japan, in a depth range of 369–1360 m with the clear mode around 1000 m (Figs 12–13). Probably endemic to the Sea of Japan.

Remarks. This species is superficially similar to some in the genus Punctulum through its rather thin periostracum and distinct teleoconch sculpture, but can be assigned to Frigidoalvania because of the close similarities in protoconch and radula characters to F. asura [ Hasegawa, 2014]. The intermediate state of characters of this species, however, may reinforce the closeness of the two nominal genera.

Figures

FIG. 2. Species of Rissoidae. A. Punctulum akibai (Yokoyama, 1926), SoJaBio stn. A2-10 (455-456 m), MIBM 39336. B. Punctulum nihonkaiensis (Hasegawa, 2014), SoJaBio stn. A2-10 (455-456 m), MIBM 39337. C-D. Frigidoalvania asura (Yokoyama, 1926), SoJaBio stn. B7-7 (470-528 m), MIBM 39340. E-F. Frigidoalvania tanseimaruae Hasegawa, 2014, SoJaBio stn. B6-7 (1,001-1,011 m). G-J. Punctulum flavum (Okutani, 1964); G-H, “shallow-water form”, SoJaBio stn. A2-10 (455-456 m), MIBM 14270; I-J, “deep-water form”, SoJaBio stn. A6-7 (2,511-2,534 m), MIBM 39334. All at the same scale; scale = 1 mm. РИС. 2.Виды Rissoidae.A. Punctulum akibai (Yokoyama,1926), SoJaBioст.A2-10 (455-456м), MIBM 39336.B. Punctulum nihonkaiensis (Hasegawa, 2014), SoJaBio ст. A2-10 (455-456 м), MIBM 39337. C-D. Frigidoalvania asura (Yokoyama, 1926), SoJaBio ст. B7-7 (470-528 м), MIBM 39340. E-F. Frigidoalvania tanseimaruae Hasegawa, 2014, SoJaBio ст. B6-7 (1001-1011 м). G-J. Punctulum flavum (Okutani, 1964); G-H, “мелководнаЯ форма”, SoJaBio ст. A2-10 (455-456 м), MIBM 14270; I-J, “глубоководнаЯ форма”, SoJaBio ст. A6-7 (2511-2534 м), MIBM 39334. Все раковины в одном масШтабе, масШтабнаЯ линейка = 1 мм.