Leptochiton inquinatus ( Reeve, 1847 )

Sirenko, Boris, 2020, New Zealand and Australian species of the genus Leptochiton (Mollusca Polyplacophora), Zootaxa 4851 (3), pp. 401-449 : 415-417

Leptochiton inquinatus ( Reeve, 1847)

( Figures 14–17 , 45D )

Chiton inquinatus Reeve 1847 : pl. 23 spec. and fig. 154.

Lepidopleurus iredalei Ashby 1921: 157 , pl. 8, figs. 3a–b; 1923: 217.

Terenochiton inquinatus ; Iredale & Hull 1929: 76, pl. 9, figs. 3–6; Powell 1979: 22, pl. 5, fig. 1.

Leptochiton (Leptochiton) inquinatus ; Kaas & Van Belle 1985: 149, fig. 67, map 27.

Leptochiton inquinatus ; Marshall 1998, 147.

Non: Lepidopleurus inquinatus ; Sykes 1896, et auct. = Leptochiton liratus (H. Adams & Angas, 1864) .

Type material. Lectotype and 2 paralectotypes ( BMNH 42.11.7.99–102). Designated in Kaas & Van Belle 1985.

Type locality. Van Diemen’s Land (in error, = New Zealand, Auckland Harbour ) .

Material examined. New Zealand, N. coast of South Island , Port Nelson, mid to low tide level, bottom of rocks embedded in slightly muddy sand, 6 spms ( ZISP 2383 ), BL. 5.0–8.0 mm, 15.10.1971, leg. J. R . Penprase; North Island , shelf NE of Taiaroa Head, 45°42’S, 170°51’E, R / V Munida , stn 1975009, 44 m, 1 spm, BL 10.0 mm, ( NMNZ M 328332 ), 08.10.1975; North Island, off East Cape, Ranfurly Bank , 37°35.80’S, 178°52.70’E, R / V Tangaroa , stn 1979679, 49 m, 1 spm, BL 8.6 mm, ( NMNZ M 319789 ), 17.01.1979; North Island, off East Cape, Ranfurly Bank , 37°37.20’S, 178°55.60’E, R / V Tangaroa , stn 1981839, 91– 93 m, 1 spm, BL 3 mm, ( NMNZ M 319783 ), 22.01.1981; North Island, off Rangaunu Bay 34°49.60’S, 173°15.00’E, R / V Tangaroa , stn 1981871, 23 m, 1 spm, BL 8.5 mm, ( NMNZ M 281873 ), 27.01.1981; North Island, off Spirits Bay , 34°25.00’S, 172°46.60’E, R / V Tangaroa , stn 1981916, 29 m, 1 spm, BL 13.0 mm, ( NMNZ M 319791 ), 03.02.1981; SW of Turakina , 40°9.00’S, 174°54.00’E, R / V Acheron , stn 1976485, 55– 57 m, 19 spms, BL 5–8.5 mm, ( NMNZ M 319762 ), 01.03.1976; Kapiti Channel , 40°51.00’S, 174°58.00’E, R / V Acheron , stn 1976482, 64 m, 1 spm, BL 12.0 mm, ( NMNZ M 319776 ), 01.03.1976; off W side of D’Urville Island , between Nile Head & Greville Harbor, 40°47.00’S, 173°48.00’E, R / V Acheron , stn 1976512, 62 m, 1 spm, BL 10 mm, ( NMNZ M 319761 ), 05.03.1976; off East Cape, Ranfurly Bank , 37°38.40’S, 178°51.70’E, R / V Tangaroa , stn 1981840, 79- 83 m, 1 spm, BL 5.5 mm, ( NMNZ M 095138 ), 22.01.1981; Spirits Bay 34°23.50’S 172°47.90’E, stn 1997013, 55 m, 1 spm, BL 13 mm, ( NMNZ M 137060 ), 28.02.1997; Bare Island, Hawke Bay , by diving, 6–10 m, under rocks, 3 spms, BL 10.5–11.0 mm, 12/1984, leg. M.H.B. O’Neill; Lyall Bay , Cook Strait , low tide, under stones, 2 spms, BL 8.0–10.0 mm. All samples without registered numbers of the NMNZ are kept in the ZISP.

Distribution. Around New Zealand, from intertidal zone to 91 m. There is a report of the species from the early Miocene of New Zealand ( Beu & Maxwell 1990).

Remarks. Two specimens were studied under SEM: specimen with body length 10.5 mm ( New Zealand, Bare Island, Hawke Bay), and specimen with body length 5.5 mm (NMNZ M 095138). Both specimens have 10 gills per side, the larger specimen with a 4.0 mm long radula, the smaller specimen has the radula 3.2 mm long and 34 transverse rows of mature teeth. The species is characterized by having low, rounded valves, with about 60 longitudinal rows of granules in central areas of the intermediate valves and about 55 rows in the antemucronal area of the tail valve, radial rows of granules in other areas, 11–17 (depends on BL) aesthetes in each granule, wide, obtusely pointed dorsal girdle scales with 8–10 sharp and narrow ribs, central teeth of radula long and narrow with wide blade, major lateral teeth with bidentate sharply pointed cusps of which the inner denticle is much smaller than the outer one.

Figures

FIGURE 14. Leptochiton inquinatus, New Zealand, N. coast of South Island, Port Nelson, BL. 7.0 mm, (ZISP 2383). A. Valve I, dorsal view; B. Valve II, dorsal view; C. Valve V, dorsal view; D. Valve VIII, dorsal view; E. Valve V, tegmentum sculpture in central area; F. Valve V, rostral view; G. Valve VIII, lateral view.

FIGURE 15. Leptochiton inquinatus, New Zealand, N. coast of South Island, Port Nelson, BL. 7.0 mm, (ZISP 2383). A, B. Dorsal and ventral scales and marginal spicules and needles; C. Dorsal scales and sutural needles; D. Dorsal scales.

FIGURE 16. Leptochiton inquinatus, New Zealand, N. coast of South Island, Port Nelson, BL. 7.0 mm, (ZISP 2383). A. Central portion of radula; B. Central and first lateral tooth of radula from anterior part.

FIGURE 17. Leptochiton inquinatus, New Zealand, N. coast of South Island, Port Nelson, BL. 7.0 mm, (ZISP 2383). A. Sutural needle; B. Dorsal scales; C. Marginal needle; D. Marginal spicule; E. Marginal scale; F. Ventral scale near margin; G. Ventral scale from mid-girdle; H. Central and first lateral teeth; I, J. Heads of major lateral teeth; K. Aesthete group in central area. Scale bar 100 μm (A–J).

FIGURE 45. Images of species of genus Leptochiton from New Zealand and Australia: A. L. badius, Australia, NSW, Sydney, Long Reef, BL 4.2 mm, (ZISP 2381) 04.02.1928; B. L. finlayi, New Zealand, N of Cavalli Islands, R/V Tangaroa, stn TAN0906/81, 115 m, BL 8.0 mm, (NMNZ M 314504); C. L. beui n. sp., New Zealand, Chatham Rise, 430 m, BL 3.5 mm, (NMNZ M 138100); D. L. inquinatus, New Zealand, Lyall Bay, Cook Strait, low tide, under stones, BL 10.0 mm, (ZISP; E. L. subantarcticus, New Zealand, South Island, shelf NE of Tiaroa Head, 50 m, BL 5.7 mm, (NMNZ M 319795).