Sabatia pyriformis, Valdés, 2008

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 692-693

Sabatia pyriformis n. sp.

Figs 47, 49F, 50B, 52D, E

TYPE MATERIAL. — Holotype MNHN 20383 and 35 paratypes MNHN 20384-20388, 2 paratypes LACM 2993 .

TYPE LOCALITY . — Passe de Hienghène , east coast of New Caledonia, 20°34’S, 164°57’E, 491-533 m [ BATHUS 1 : stn CP 698 ] .

MATERIAL EXAMINED. — New Caledonia proper. VAUBAN: Hienghène , 20°33’S, 164°57’E, 533-610 m, 7 dd .

stn 40, 22°30’S, 166°24’E, 250-350 m, 4 dd, paratypes ( MNHN Vanuatu or New Caledonia, locality and date undetermined, 20384) . — BATHUS 1 : stn DE 682 , Grande Passe de Touho , 1 dd .

20°47’S, 165°21’E, 491-500 m, 1 dd; stn DE 696, Passe de Hien- Fiji. MUSORSTOM 10: stn CP 1341, Bligh Water, 16°53’S, ghène, 20°34’S, 164°57’E, 497-520 m, 21 lv, (1 destroyed to 177°44’E, 500-614 m, 1 dd, paratype ( MNHN 20386).

dissect the radula and gizzard plates, 1 lv, dissected), paratypes Wallis Island. MUSORSTOM 7: stn DW 523, 13°12’S, ( MNHN 20385; Figs 49 F, 50 B); stn DE 697, 20°34’S, 164°58’E, 176°16’W, 455-515 m, 2 dd; stn DW 601, 13°19’S, 176°17’W, 570-650 m, 16 dd; stn CP 698, 20°34’S, 164°57’E, 491-533 m, 3 350 m, 8 dd, paratypes ( MNHN 20388); stn DW 604, 13°21’S, dd, holotype ( MNHN 20383; Figs 52D, E), 2 paratypes ( LACM 176°08’W, 415-420 m, 1 dd.

2993). — BATHUS 2 : stn CP 743 , Passe de Boulari , 22°36’S, Tonga. BORDAU 2 : DW 1569 , NW of Tongatapu, 21°02’S, 166°26’E, 713-950 m, 16 dd . — BATHUS 4 : stn CP 948 , Passe de 175°19’W, 433 m, 1 dd, paratype ( MNHN 20387 ) .

DISTRIBUTION. — Collected from Fiji, New Caledonia, Tonga and Wallis and Futuna (Fig. 47), in 350-713 m, live in 497-520 m.

DESCRITION. — Shell morphology. Length 7 mm; width 5 mm (holotype). Shell solid, pyriform, with convex sides and only 1 whorl visible (Fig. 52D). Apex depressed, not umbilicate (Fig. 52E), with the aperture lip rising conspicuously from the left side, forming a long wing. Anterior end of the shell rounded. Aperture as long as the shell, wider anteriorly and narrower posteriorly. Columellar margin conspicuously thickened, with a large callus composed of numerous tubercles and situated on the posterior half of the aperture. Sculpture of several punctuated spiral grooves, absent from the middle area of the shell, and more densely concentrated towards the posterior end. Near the apex, the punctuations are larger and more densely arranged, and the areas between the spiral grooves are thicker. Colour uniform cream to light brown.

Anatomy. The digestive system lacks gizzard plates. The radular formula is 17 x 1.0. 1 in a paratype from New Caledonia (BATHUS 1 stn DE 696). The lateral teeth are hook-shaped with several large denticles (Fig. 49F). They have a large base and a short, curved cusp.

The reproductive system is monaulic (Fig. 50B). The ampulla is very large and convoluted. It connects to the short post-ampullary duct. The seminal receptacle enters the post-ampullary duct, which continues distally to the common general atrium. The bursa copulatrix also enters the common atrium. From the gonopore a short, open seminal groove runs anteriorly to the protrusible cephalic penis and the prostate. The prostate is very short and wide.

REMARKS. — Sabatia pyriformis is very similar to Sabatia supracancellata (Schepman, 1913) in both shell morphology and anatomy. Both species lack gizzard plates and have a conspicuous wing on the apex of the shell. Differences between them include the radular teeth, which are denticulate in S. supracancellata and smooth in S. pyriformis . Also, the shell of S. supracancellata is more elongate and the edges are less convex than in S. pyriformis .

ETYMOLOGY. — From the Latin pyriformis (pear-shaped), in reference to the shape of the shell.