Episiphon joanae, Scarabino & Scarabino, 2010

Scarabino, Victor & Scarabino, Fabrizio, 2010, A new genus and thirteen new species of Scaphopoda (Mollusca) from the tropical Pacific Ocean, Zoosystema 32 (3), pp. 409-423 : 417-418

Episiphon joanae n. sp.

( Fig. 3 H-J)

TYPE MATERIAL. — Fiji. Lau Ridge , BORDAU 1 , stn DW 1469, 19°40’S, 178°10’W, 392-407 m, 1 dd holotype ( MNHN 22788 ) ; 2 dd paratypes ( MNHN 22789 ) .

TYPE LOCALITY. — Fiji, Lau Ridge, 19°40’S, 178°10’W, 392-407 m ( BORDAU 1, stn DW 1469).

ETYMOLOGY. — Named after Joan Pickering (BMNH) for her assistance at the time of Scarabino’s (1995) monograph on Scaphopoda.

OTHER MATERIAL EXAMINED. — Tonga. BORDAU 2, stn DW 1585, 18°33’S, 173°57’W, 578 m, 3 dd.

Wallis Island. MUSORSTOM 7, stn DW 604, 13°21’S, 176°08’W, 415-420 m, 2 dd.

Vanuatu. MUSORSTOM 8, stn DW 1065, 16°16’S,

167°21’E, 360-419 m, 1 lv, 3 dd. — Stn CP 1131-1132, 15°38’S, 167°03’- 167°04’E, 140-182 m, 2 dd.

Solomon Islands. SALOMON 2, stn CP 2176, 09°09’S, 158°59’E, 579-875 m, 1 dd. — Stn CP 2184, 09°17’S, 160°00’E, 464-523 m, 2 dd. — Stn CP 2260, 08°04’S, 156°55’W, 399-427 m, 1 dd.

DISTRIBUTION. — Solomon Islands, Vanuatu, Fiji, Wallis Island, Tonga. Live at 360 m. Shells at 182- 579 m.

DESCRIPTION

Shell 11 mm long, well curved, translucent, glossy, section slightly dorsoventrally depressed throughout, dorsal wall thicker than ventral wall. Arc located close to centre of shell. Sculptured by 24 slim ribs, no secondary ribs observed. Apex oblique, ventral side longer, with protruding callus, thicker in ventral side and lumen circular with short projecting pipe, anterior aperture oblique.

Radula: rachidian tooth with three central projections on the internal face and anterior border curved, smooth. Lateral teeth with pronounced head with an elevated posterior angle, a strong and pointed primary cusp and a secondary denticle at the external border. Marginal teeth slightly angled.

Measurements of holotype: L 7, W 0.7, w 0.3, arc 0.25 at 3 from apex.

REMARKS

Episiphon joanae n.sp. has a similar apical outline to E. lacteum n. sp., here described, but is more curved, shiny and translucent and has a well-defined sculpture.

Figures

FIG. 3. — A-D, Episiphon wallisi n. sp. holotype (6.5 mm), Wallis Island, 13°21’S, 176°08’W, 415-420 m (MUSORSTOM 7 stn DW 604);A, lateral view of shell; B, dorsal view of shell; C, frontal view of apex; D, sculpture at the posterior third of shell; E-G, Episiphon indefensum n. sp. holotype (7.9 mm), Solomon Islands, 8°47’S, 157°38’E, 762-1060 m (SALOMON 2 stn CP 2182); E, lateral view of shell; F, dorso-frontal view of apical area; G, sculpture at the middle of shell; H, I, Episiphon joanae n. sp. holotype (7 mm), Fiji, Ride de Lau, 18°43’S, 178°23’W, 392-407 m (BORDAU 1 stn DW 1469); H, lateral view of shell; I, latero-dorsal view of apical area; J, Episiphon joanae n. sp., radula, rachidian and lateral teeth; K, L, Episiphon lacteum n. sp. holotype (16 mm), Waterwitch Bank, Wallis Island, 12°31’S, 176°40’W, 275-295 m (MUSORSTOM 7 stn DW 538); K, lateral-dorsal view of apical area; L, lateral view of shell. Scale bars: F, G, I, K, 100 μm; J, 10 μm.