Frigidoalvania asura ( Yokoyama, 1926 )

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 asura ( Yokoyama, 1926)

( Fig. 2 C–D )

Rissoa (Apicularia?) asura Yokoyama, 1926: 273 , pl. 33, fig. 15 (see Hasegawa [2014] for more detailed synonymy).

Material examined. SoJaBio B 6-7, MIBM 14992; SoJaBio B 7-7, MIBM 39340 ( Fig. 2 C–D ) [depth range: 470–1011 m].

Additional material examined (cited from Hasegawa, 2014). ZIN 33623 , off SW Sakhalin, N. Sea of Japan, 202–222 m , 49°14.8’N, 141°09.7’E, 100 m; ZIN 33625 , Peter the Great Bay, 42°18.8’N, 131°09.5’E, 247 m ; ZIN 36609 , Peter the Great Bay, 42°15.4’N, 130°44.6’E, 140 m ; ZIN 36610 , Peter the Great Bay, 42°28.0’N, 131°40.5’E, 125 m ; ZIN 36611 , Peter the Great Bay, 42°25.7’N, 132°36.8’E, 157– 140 m ; ZIN 36612 , Peter the Great Bay, 42°33.0’N, 132°51.0’E, 133 m ; ZIN 36613 , Peter the Great Bay, 42°35.3’N, 132°51.1’E, 110 m ; ZIN 36614 , Peter the Great Bay, 42°35.7’N, 133°06.2’E, 143 m ; ZIN 36615 , Peter the Great Bay, 42°38’N, 132°43.2’E, 100 m [depth range: 100–247 m] .

Distribution. Widely distributed in the Northwest Pacific, from the eastern part of the Okhotsk Sea to the southernmost part of the Sea of Japan, and to Sagami Bay along the Pacific coast. Depth range in the Sea of Japan is 100–1011 m.

Remarks. Although this species was considered by Hasegawa [2014] to be widely distributed in the North Pacific and its marginal seas, there are con- siderable differences in the shape and sculpture of the shell between geographic areas, even within the Sea of Japan. More detailed analysis using molecular techniques may reveal genetic and thus taxonomic distinctions.

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.