Lepidochitona cinerea (Linneus, 1767)

Sirenko, B. I., 2023, Lepidochitona bondarevi sp. nov. (Mollusca: Polyplacophora) from the Black Sea and its relatives, Ruthenica, Russian Malacological Journal (Berlin, Germany) 33 (4), pp. 149-165 : 150-153

Lepidochitona cinerea (Linneus, 1767)

( Figs 1A, 2–7)

Complete synonymy in Kaas, Van Belle [1985] and Dell’Angelo, Smriglio [2001].

Here I cite only the publications on the Black Sea.

Chiton marginatus .– Milachewitch, 1909a: 154; 1909b: 316; 1916: 142.

Lepidochitona cinerea .– Starobogatov, 1972: 64, pl. I, fig. 1; Kaas, Van Belle, 1985: 84, fig. 39, map 17; Anistratenko, Anistratenko, 2001: 46, fig.14; Micu, 2004: 88; Bondarev, Revkov, 2017: 15.

Lepidochiton marginatus .– Jakovleva, 1952: 72, fig. 29, pl. 3, fig. 5.

Type material. In the Linnean Society of London .

Type locality. In O. Norvegico.

Material examined. More than 220 spms. Norway Sea, Tromsø Island, intertidal pool, about 100 spms ( ZIN 2469 ) BL 3.0–15.0 mm, 16.05.1995 ; North Sea , Helgoland Islands, 5 spms ( ZIN 209 ), BL (9.0–10.0 mm) ; Baltic Sea , Store Belt, 4 spms ( ZIN 208 ), BL 8.0–15.0 mm ; Mediterranean Sea , 4 spms ( ZIN 211 ), BL 3.0–7.0 mm ; Aegean Sea , Smirna, 1 spm ( ZIN 215 ) BL 3.0 ; Marmara Sea , Prinkipo, 15 spms ( ZIN 216 ), BL 3.0–5.0 mm ; Black Sea , Northwest of the Black Sea, Karkinitskiy Bay, 45°40’N, 32°08’E, 33 m, 1 spm, BL 7.0 mm, 23.09.1981 ; 45°32’N, 32°13’E, 38 m, 1 spm, BL 9.0 mm, 06.06.1981 ; 45°31’N, 32°12’E, 38 m, 1 spm, BL 7.0 mm, 23.09.1981 45°38’N, 32°45’E, 22 m, 5 spms, BL 2.0.–5.0 mm, 30.08.1981 ; 46°00’3’’N, 32°28’01”E, 15 m, muddy sand with shells, 4 spms, BL 5.1–9.2 mm, 16.10.1979 ; 46°00’00’’N, 32°27’5”E, 14–15 m, muddy sand with shells, 1 spm, BL 3.5 mm, 18.10.1979 ; Crimea Peninsula , Sevastopol Bight, 4 spms, ( ZISP 240 ), BL 3.8–6.7 mm ; Golubaja Bight , 4–6 m, 1 spm, BL 5.0 mm, 12.08.2015 ; Omega Bight , 2–3 m, on Rapana venosa , 2 spms, BL 3.0– 3.5 mm, 11.08.2015 ; Omega Bight , 2–3 m, on Rapana venosa , 3 spms, BL 3.0– 4.5 mm, June, 2015 ; Omega Bight , 2–3 m, on Rapana venosa , 1 spm, BL 6.5 mm, 2014 ; near Balaklava Bight , 43 spms ( ZIN 217 ), BL 2.0– 5.5 mm ; Kazachja Bicht , 11–12 m, 7 spms, BL 4.5 –8.0 mm, 26.05.1977 ; Kara Dag , 3 m, on Rapana venosa , 2 spms, BL 4.0–8.0 mm, 15.07.2004 nearAlupka, 44°24’20’’N, 34°03’20”E, 14.6 m, sand with shells, 1 spm ( ZIN 226 ), BL 3.5 mm, August, September 1909 ; East of the Black Sea, northwest of Anapa, 44°56’45’’N, 37°00’15’’E, 31 m, on small shells, 13 spms ( ZIN 220 ), BL 2.5 –5.0 mm, May, 1910 .

Distribution. Eastern Atlantic from Norwegian coast (Tromsö) to northwestern coast of Morocco including Norwegian, North, west Baltic, Mediterranean, Aegean, Marmara and Black seas. Reports of findings of this species off the eastern and western shores of North America [ Kaas, Van Belle, 1985] are most likely based on misidentifications.

Diagnosis. Chiton usually of small size, up to 16.0 mm, rarely up to 25.0 mm, color of tegmentum very variable from completely orange, flesh-colored, red or sandy to light brown with white, orange or dark brown spots; valves subcarinated, little beaked, slightly elevated (dorsal elevation 0.30–0.44), mucro anterior (ratio of length of postmucronal area to length of antemucronal area 1.09–1.44). Head valve equal to tail valve or slightly larger than tail valve (ratio of width of head to width of tail valve 1.00–1.19). Tegmentum evenly sculptured all over with fine diamond-shaped granules arranged in quincunx patterns, each granule has 5–20 rounded and of about the same size pores of aesthetes. Slit formula 9–10/1/8–11. Girdle dorsally clothed with small, oblong, slightly bent, obtusely pointed calcareous corpuscles (60–90 µm); irregularly scattered among these occur slender, slightly bent needles (65–250 µm); marginal needles obliquely grooved on dorsal side in two directions (feather-like). Central tooth of radula tulip-shaped with a rounded blade; first lateral tooth higher than central; major lateral tooth with tridentate cusp, median denticle somewhat larger than the others. From eleven to sixteenth gills arranged from valve III to valve VII.

Remarks. The Black Sea representatives of this species differ from specimens from other parts of the range by small body size (BL up to 9.2 mm), shorter apophyses of the tail valve, and shorter postmucronal areas ( Table 1). Most individuals of this species from the Black Sea have smooth dorsal spicules, but sometimes there are specimens with very short grooves at the top of spicules, as in individuals from the Mediterranean Sea. Kaas and Van Belle [1985] do not mention these short grooves at top of dorsal spiculae in specimen from Netherlands.

According to Kaas and Van Belle [1985], L. cinerea inhabits from the intertidal to 50–70 m. In the Black Sea this species is found from 0.2 to 38 m.