Nierstraszella lineata ( Nierstrasz, 1905 )

Sigwart, Julia D., 2009, The deep-sea chiton Nierstraszella (Mollusca: Polyplacophora: Lepidopleurida) in the Indo-West Pacific: taxonomy, morphology and a bizarre ectosymbiont, Journal of Natural History 43 (7 - 8), pp. 447-468 : 451-452

Nierstraszella lineata ( Nierstrasz, 1905)

Chresonymy and synonymy revised from Saito (1997), Sirenko (1992) and Schwabe et al. (2008).

Lepidopleurus lineatus Nierstrasz, 1905, p. 8 , figures 4, 48–51; Nierstrasz 1906, p. 146, 157; Ferreira 1979, p. 163, figures 23, 24; Dell’Angelo and Palazzi 1989, p. 80; Higo et al. 1999, p. 23.

Lepidopleurus niasicus Thiele, 1906, p. 13 , pl. 29, figures 1–5 (Lectotype in ZMB Moll 59912a [designated by Schwabe et al. 2008], two paralectotypes ZMB Moll 59912b, type locality: Indonesia, northwest off Nias Island, 01 ° 47.19 N 96 ° 58.79 E, Valdivia St. 203, 660 m); Kilias 1995, p. 166.

Leptochiton diomedeae Berry, 1917, p. 1 , pl. 1, figures 1–3, pl. 2 [holotype, US National Museum, Smithsonian Institute, Washington DC, USNM 215625 (not seen), holotype pro parte (girdle preparation) RMNH MOL.K.4897; type locality: Japan, Honshu, off Shiono Misaki Light (33 ° 25.109 N 135 ° 37.209 E), U.S. S. Albatross St. D4967 (off Shio Misaki Light), 244–253 fathoms (446– 463 m)]; Ferreira 1979, p. 163, figures 21, 22; Kaas and Van Belle 1985, p. 101 – 103; Higo and Goto 1993, p. 3; Ogasawara 2003, p. 277.

Lepidopleurus diomedae [sic]: Taki 1938, p. 412; Sirenko 1973, p. 59 (English version).

Lepidopleurus (Deshayesiella) diomedeae: Taki and Taki 1929, p. 162 ; Taki 1961, p. 3; Taki 1962, p. 32.

Lepidopleurus (Deshaysiella) [sic] diomedeae: Itoigawa et al. 1977, p. 57 ; Ogasawara 2003, p. 277.

Leptochiton lineatus: Kaas and Van Belle 1980, p. 74 ; Kaas 1982, p. 87; Kaas 1985, p. 309; Kaas and Van Belle 1985, p. 113, figure 49; Kaas 1990, p. 176; Kaas and Van Belle 1998, p. 110; Slieker 2000, p. 92, pl. 34, figure 2.

Leptochiton niasicus: Kaas and Van Belle 1980, p. 89 ; Kaas and Van Belle 1985, p. 116 –118, figure 51; Kaas and Van Belle 1998, p. 130.

Lepidopleurus belknapioides Leloup, 1981, p. 317 , figure 1, pl. 1, figure 1–3 (holotype MNHN 5862, one paratype RBINS, type locality: Philippines, 13 ° 46.99 N 120 ° 29.59 E, Campagne MUSORSTOM 1: stn CP44, 592– 610 m); Kaas and Van Belle 1985, p. 113; Kaas and Van Belle 1998, p. 29; Slieker 2000, p. 139.

Nierstraszella lineata: Sirenko 1992, p. 84 , figures 3–7, 8A–D, 9; Saito 1997, p. 46, pl. 2, figure 2; Sirenko 1998, p. 1; Sirenko 2001, p. 61, figures 196–197; Sirenko 2004, p. 112; Saito 2001, p. 9, pl. 4, figure 18; Saito 2004, p. 84, figure 2B; Saito 2005, p. 104; Schwabe 2005, p. 52, pl. 1, figure 1; Saito 2006, p. 210, 220; Schwabe 2006a, p. 108; Schwabe 2006b, p. 20. (Where figures are not provided these records are assumed to refer to N. lineata s.s.)

Leptochiton diomedae [sic]: Higo et al. 1999, p. 23.

Leptochiton diomedeae: Slieker 2000, p. 96 , pl. 36, figure 1.

Type material

Lectotype ( ITZ Moll. 3.05.011) designated by Ferreira (1979, p. 163).

Type locality

Savu Sea, ‘‘Siboga’’ sta. 297, 10 ° 399 S 123 ° 409 E, 520 m.

Material examined

Lepidopleurus lineatus lectotype ( ITZ); Lepidopleurus belknapioides holotype (MNHN 5862); L. belknapioides paratype ( RBINS); Lepidopleurus diomedeae holotype pro parte RMNH MOL.K.4897; RMNH MOL.HLS.1746; RMNH MOL.HLS.2010; RMNH MOL.K.4967; for new expedition material from the West Pacific please see Appendix 1 .

Diagnosis

As for genus. Valves covered in thick periostracum in raised pustules forming zigzag lines. Megalaesthetes surrounded by many irregularly distributed micraesthetes forming a lattice-like pattern over the whole valves. Girdle covered in small clubshaped spicules. Gills increasing in number with the size of the animal, from six in juvenile specimens (1.2–1.4 mm wide) to 12–18 per side in adult specimens.

Description

The morphology of this species has been thoroughly and accurately described, particularly by Kaas and Van Belle (1985) and Sirenko (1992).

Distribution

Widely distributed in the Western Pacific, in Japan, Philippines, Solomon Islands, Indonesia, Vanuatu; 200–1750 m (e.g. Sirenko, 1992, 2001; Saito 2005; Schwabe et al. 2008). Material studied here represents the deepest record for the species (‘‘Panglao 2005’’ sta. CP2353, CP 2356). Locally abundant species and common on sunken wood.

Remarks

Kaas and Van Belle (1985, p. 113) correctly included L. belknapioides in synonymy with L. lineatus . The descriptions provided for Lepidopleurus lineatus ( Kaas and Van Belle 1985, p. 113–114, figure 49; Sirenko 1992), Lepidopleurus diomedeae ( Kaas and Van Belle 1985, p. 101–103, figure 44), Lepidopleurus niasicus ( Kaas and Van Belle 1985, p. 116–118, figure 51) are all applicable to Nierstraszella lineata . Conchological features in this species are plastic and show a range of morphologies as noted by Sirenko (1992). The figures included in earlier descriptive works, as well as all others included in the chresonymy above are clearly illustrations of N. lineata . The species is easily identifiable from the distinctive raised periostracum which creates pustules arranged in diagonal or zig-zag arrangement. Published SEM images of valve surfaces in Sirenko (1992) and Saito (2001) show the clusters of raised pustules as well as distinctive aesthete arrangement in this species (Figures 2,3). The differences that separate Lepidopleurus diomedeae , Lepidopleurus niasicus and L. belknapioides in earlier descriptions are minor and are thoroughly discussed in Sirenko’s revision of the genus ( Sirenko 1992).