Parachiton acuminatus (Thiele, 1909)

Schwabe, Enrico, Sirenko, Boris I. & Seeto, Johnson, 2008, A checklist of Polyplacophora (Mollusca) from the Fiji islands, Zootaxa 1777, pp. 1-52 : 5

Parachiton acuminatus (Thiele, 1909)

( Figure 1A )

Chresonymy in Kaas & Van Belle (1985: 165).

Lepidopleurus (Parachiton) acuminatus Thiele 1909a: 13 , pl. 1, figs 61–73; 1931: 7; Iredale & Hull 1927: 45; Powell 1937: 219; 1979: 22; Cotton & Godfrey 1940: 479; Laghi, Russo & Dell’Angelo 1980: 4; Kaas & Van Belle 1985: 163; Boss & Bieler 1991: 42; Saito 1996: 162; Van Belle 1999: 69; Dell’Angelo & Smriglio 1999: 80; 2001: 80; Gowlett-Holmes 2001: 75; Schwabe 2004: 3144.

Parachiton acuminatus ; Cotton & Weeding 1939: 197; Iredale & McMichael 1962: 28; Sirenko 1997: 13; Slieker 2000: 8, 52, 138, pl. 14, fig. 1; Schwabe 2001: 27; 2006a: 110; Saito 2003: 13; 2006b: 172.

Lepidopleurus acuminatus ; Van Belle 1975: 140, pl. 2, fig. 8; Spencer & Willan 1995: 11; Kilias 1995: 155; Schwabe 2006a: 110.

Leptochiton (Parachiton) acuminatus ; Van Belle 1983: 54, pl. 3, fig. 6; Kaas & Van Belle 1980: 2; 1985: 165, fig. 76; 1998: 12; Cesari 1987: 13.

Parachiton cf. acuminatus ; Burghardt et al. 2006: 30.

Locus typicus: Papua New Guinea, Bismarck Archipelago, Neu Lauenburg [= Duke of York Islands, 4°10’S 152°27’E].

Primary type: Lectotype (ZMB Moll 101921) designated by Kilias (1995: 155).

Type (s) without name-bearing function: One paralectotype ( ZMH, Godeffroy collection [6878]).

Material examined: UF 296065: 1 adult spm., Viti Levu, Laucala Bay, behind USP Maritime Studies buildings 18°09’03’’S 178°27’14’’E, 0–1 m, sand and mud reef flat, under dead coral rubble and Halimeda sp., leg. Lisa Kirkendale & Victor Bonito, 0 6 October 2001 (LAK-005), wet.

Habitat: Our own observation in the Samoan Islands confirm the herein reported habitat. The species shows a preference for solid substratum, which is partly burried in sediment.

Distribution: Papua New Guinea (type locality), Samoa (Schwabe 2001: 27), Nansei Islands, Japan ( Saito 2003: 13).

Remarks: This is the first record of this species from Fiji.

The status of the name-bearing type of this species was unclear for a long time. According to Thiele’s original description (1909a: 14) it seemed that he had only studied a single specimen: “Die Länge des Tieres beträgt 17 mm, die Breite 8 mm ” [the length of the animal is 17 mm, the width 8 mm]. Kaas & Van Belle (1985: 165) correctly recognised that there must be at least two specimens involved. They designated one as “ paratype ” (ZMHU [= ZMB] 101921), which is dry, lacking the head valve, and measures 16 x 8 mm, and a second disarticulated one, which they regarded the holotype without further comments. Unfortunately, they wrote that the “ holotype ” is also in the ZMB, which is wrong. Kilias (1995: 155) listed the single specimen ZMB Moll 101921 as holotype, unaware that the ZMH also holds a specimen. The latter is partly disarticulated, had its radula removed, is from the Godeffroy collection (6878), and has a label in Thiele’s handwriting (but without the asterisk he normally used to indicate types). This seems to be the specimen Thiele used for his description. Unfortunately Kilias’ interpretation of which specimen was the holotype fully meets the requirements of Art. 74.6 of the ICZN, and thus the specimen ZMB Moll 101921 became the lectotype of Lepidopleurus acuminatus . Therefore, the above-mentioned specimen from the ZMH is here regarded the paralectotype.

Figures

FIGURE 1. A, Parachiton acuminatus (Thiele, 1909), UF 296065: Fiji, Viti Levu, Laucala Bay, behind USP Maritime Studies buildings 18 ° 09 ’ 03 ’’ S 178 ° 27 ’ 14 ’’ E, dorsal view. B, Parachiton puppis Hull, 1923, UF 297662: Fiji, Viti Levu, Man Friday Resort, 80 km west of Suva [18 ° 10 ’ S 177 ° 40 ’ E], dorsal view. C – D, Nierstraszella lineata (Nierstrasz, 1905). C, Nierstraszella lineata (Nierstrasz, 1905) ZSM Mol 20034397, Japan, Suruga-wan, right lateral view, anterior at right. D, Lectotype of Lepidopleurus niasicus Thiele, 1906 ZMB Moll 59912 a, Indonesia, Northwest off Nias Island, 01 ° 47.1 ’ N 96 ° 58.7 ’ E, Valdivia St. 203, dorsal view. E, Callochiton neocaledonicus Kaas & Van Belle, 1990, ZSM Mol 20061630: Fiji, Viti Levu, Laucala Bay, north side of Nukumbutho Island 18 ° 10.474 ' S 178 ° 28.343 ' E, dorsal view. F, Chiton (Rhyssoplax) ectypus (de Rochebrune, 1884), ZISP: Fiji, Cicia Island [17 ° 45 ’ S 179 ° 18 ’ W], Callisto St. 83, dorsal view. All scale bars 2 mm.