Loricella scissurata (Xu, 1990)

Sirenko, Boris, 2021, Composition of the genus Loricella (Mollusca: Polyplacophora: Loricidae) and the description of two new species, Zootaxa 4981 (2), pp. 275-300 : 282-284

Loricella scissurata (Xu, 1990)

( Figs. 8–10 )

Loricella oviformis ; Kaas 1985: 310–314, figs. 48–54 (in part, non Squamophora oviformis Nierstrasz, 1905 ).

Sinolorica scissurata Xu 1990: 376 , fig. 2.

Loricella scissurata ; Saito 2005: 107, figs. 10–19, pl. 1D–I; 2011: 76, fig. 5D; Sirenko 2018: 332, figs. 31– 32, 37E.

Type material. Holotype ( IOAS, Ky4B-70), not seen.

Type locality. East China Sea, 26°30’N, 124°40’E, 220 m.

Material examined. Taiwan, Bashi Channel, N/ O Fishery Researcher 1, “ TAIWAN 2000” stn CP35, 22°01.8’N, 120°26.6’E, 246 m, 1 spm, BL 10.8 mm (MNHN-IM-2013-59984), 31.07.2000 ; north of South China Sea, to north off Macclesfield Bank, “ZhongSha 2015” stn CP4135, 19°59’N, 114°38’E, 211–218 m, 7 spms ( MNHNIM- 2013-61685, MNHN-IM-2013-59985, MNHN-IM-2013-59986, MNHN-IM-2013-59987, MNHN-IM-201359988, MNHN-IM-2013-59989, MNHN-IM-2013-59990), BL 12.0–15.0 mm, 23.07.2015 ; stn CP4136, 19°59’N, 114°34’E, 249–250 m, 2 spms (MNHN-IM-2013-61742; MNHN-IM-2013-59992), BL 12.0–13.0 mm, 23.07.2015 ; Indonesia, “Corindon”- Makassar-Expedition, stn CH229, 00°02’S, 119°50’E, 411–445 m, 1 spm (MNHN-IM-2013 -59991), BL 15.5 mm, 1980. Solomon Islands, SALOMON 1, stn DW 1830, 10°11’N, 151°19’E, 500–563 m, 1 spm (MNHN-IM-2013-59993) , BL 16.5 mm, 04.10.2001 .

Distribution. The southeast East China Sea (205–520 m: Saito 2005), Sagami Bay and Omurodashi Bank (187–350 m: Saito 2011), Taiwan (246 m: Sirenko 2018), Macclesfield Bank (218–249 m: this study), Solomon Islands (500–563 m: this study).

Remarks. Dorsal scales have numerous pits near the edge of the distal part. Aspecimen from the Solomon Islands, BL 16.5 mm, has a dorsal elevation of 0.38, slit formula 15/1/sinus + 4 obsolete, 18 gills on each side extending from valve III to valve VII, nephridiopore and gonopore arranged between 4–5 and 6–7 gills accordingly counted from the posterior, and a radula 3.0 mm long with 32 transverse rows of mature teeth. Aspecimen from Taiwan, BL 10.5 mm, has dorsal elevation 0.34, slit formula 16/1/sinus + 8 obsolete, 16 gills on each side extending from valve III to valve VIII, nephridiopore and gonopore arranged between 3–4 and 5–6 gills accordingly counted from the posterior, and a radula 2.3 mm long with 33 transverse rows of mature teeth.

Loricella scissurata differs from L. vanbellei by having pits near edge of distal part on dorsal scales (vs granules and grooves on dorsal scales of L. vanbellei ). Moreover the latter has 15 radial ribs on head valve (no radial ribs in L. scissurata ).

Figures

FIGURE 8. Loricella scissurata, Solomon Islands, (MNHN-IM-2013-59993), BL 16.5 mm. A. Valve I, dorsal view; B. Valve II, dorsal view; C. Valve VII, dorsal view; D. Valve VIII, dorsal view; E. Valve VII, detail of tegmentum in central and lateral areas; F. Valve VII, rostral view; G. Valve VIII, lateral view.

FIGURE 9. Loricella scissurata, Solomon Islands, (MNHN-IM-2013-59993), BL 16.5 mm. A. Dorsal, marginal and ventral scales; B. Dorsal scales, ventral view; C. Dorsal scale, lateral view; D, E. Dorsal scales, dorsal views.

FIGURE 10. Loricella scissurata, Solomon Islands, (MNHN-IM-2013-59993), BL 16.5 mm. A, C. Marginal needles and ventral scales; B. Dorsal scales and dorsal bristle with spicule; D. Central portion of radula.