Acteocina gracilis
Creators: name: Valdés, Ángel
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Cephalaspidea
Tornatinidae
Acteocina
Acteocina gracilis

description: <i>Acteocina gracilis</i> (A. Adams <i>in</i> Sowerby, 1850) Figs 59E, F, 60C, D, 61 <i>Bulla gracilis</i> A. Adams <i>in</i> Sowerby, 1850 [<i>in</i> 1848-50]: 569, pl. 121, fig. 36. TYPE MATERIAL. — Not examined. TYPE LOCALITY. — China Seas. MATERIAL EXAMINED. — <b>Coral Sea</b>. MUSORSTOM 5: stn 349, Passage, 19°00’S, 163°14’E, 386-400 m, 8 dd. Chesterfield Islands, 19°34’S, 158°34’E, 275 m, depth, 2 dd. <b>New Caledonia proper</b>. <i>VAUBAN</i>: stn 40, 22°30’S, 166°24’E, <b>North of New Caledonia</b>. LAGON: stn 502, Lagon Nord, 250-350 m, 1 dd. — MUSORSTOM 4: stn DW 203, 22°36’S, 19°08’S, 163°30’E, 190 m, 1 dd. — MUSORSTOM 4: stn DW 167°05’E, 105-110 m, 1 dd. — LAGON: stn 830, Secteur de 149, 19°08’S, 163°23’E, 155 m, 1 dd; stn DW 150, 19°07’S, Poindimié, 20°49’S, 165°19’E, 105-110 m, 1 dd. — BATHUS 1: 163°22’E, 110 m, 4 dd; stn DW 151, 19°07’S, 163°22’E, 200 stn DW 674, Grande Passe de Touho, 20°49’S, 165°19’E, 105- m, 3 dd; stn CC 173, 19°02’S, 163°19’E, 250-290 m, 1 dd; stn 110 m, 1 dd; stn CP 713, Passe SE de Ngoe, 21°45’S, 166°37’E, CC 174, 19°00’S, 163°18’E, 365 m, 3 dd; stn CC 175, 18°59’S, 250 m, 1 dd. — BATHUS 2: stn DW 715, Ile des Pins, 22°39’S, 163°17’E, 355 m, 23 dd, 1 lv, destroyed to dissect the reproduc- 167°11’E, 202-227 m, 1 dd; stn CP 755, Passe de Dumbéa, tive system (Figs 60 C, D). — BATHUS 4: stn DW 903, Grand 22°22’S, 166°14’E, 495 m, 2 dd. <b>Loyalty Ridge</b>. BATHUS 3: stn DW 790, Mont J, 23°49’S, 176°08’W, 415-420 m, 4 dd; stn DW 635, SW Pacific 13°49’S, 169°48’E, 685-715 m, 3 dd; stn DW 793, 23°47’S, 169°49’E, 179°56’W, 700-715 m, 2 dd. 731-751 m, 5 dd. <b>Tonga</b>. BORDAU 2: stn DW 1523, Eua, 21°18’S, 175°00’W, 300- <b>Vanuatu.</b> MUSORSTOM 8: stn DW 976, 19°25’S, 169°27’E, 302 m, 1 dd; stn DW 1531, 21°12’S, 174°56’W, 970-983 m, 1 160-182 m, 17 dd; stn DW 1094, 15°08’S, 167°12’E, 312-314 dd; stn DW 1537, 21°41’S, 175°19’W, 391-421 m, 2 dd; stn DW m, 1 dd; stn DW 1100, 15°05’S, 167°10’E, 258-265 m, 1 dd; stn 1552, S of Nomuka Islands, 20°38’S, 174°58’W, 491-500 m, 1 DW 1106, 15°05’S, 167°12’E, 305-314 m, 2 dd. dd; stn DW 1586, Vava‘u Islands, 18°34’S, 173°55’W, 440-487 <b>Fiji</b>. BORDAU 1: stn DW 1469, 19°40’S, 178°10’W, 314-377 m, m, 1 dd; stn DW 1587, 18°37’S, 173°54’W, 309-400 m, 2 dd; 1 dd. stn DW 1601, centre of Ha‘apai Islands, 20°50’S, 174°57’W, <b>Wallis and Futuna</b>. MUSORSTOM 7: stn DW 505, Futuna Is- 200-487 m, 1 dd; stn DW 1611, Seamount, 23°00’S, 175°47’W, land 14°19’S, 178°04’W, 245-400 m, 1 dd; stn DW 601, Wallis 278-323 m, 1 dd; stn DW 1612, 23°02’S, 175°47’W, 327-342 m, Island, 13°19’S, 176°17’W, 350 m, 3 dd; stn DW 604, 13°21’S, 1 dd (Figs 59E, F). DISTRIBUTION. — Found in China, Philippines and Japan (Habe 1955). Records herein from the Coral Sea, Fiji, New Caledonia, Tonga, Vanuatu and Wallis and Futuna (Fig. 61), in 110-970 m, live in 355 m. DESCRIPTION. — <i>Shell morphology</i>. Length 11 mm, width 4 mm (largest specimen examined). Shell solid, elongate, fusiform, with almost parallel sides (Fig. 59E). Body whorl very large; spire conical, variable in length, with 2-3 whorls. Suture canaliculate. Protoconch flattened, about 1.2 whorls and 150 Μm in diameter (Fig. 59F). It is only attached to the teleoconch by the aperture. Umbilicus closed. Aperture very long, about 7/10 of the shell length, narrow, wider anteriorly, narrowing gradually towards the posterior end. Columellar margin thickened, oblique, with a long, thin callus running from its anterior end to about 1/3-1/5 of the aperture length. Sculpture of fine spiral lines, crossed by faint axial lines, not visible in all specimens. Colour uniformly whitish. <i>Anatomy</i>. The digestive system contains 3 smooth and irregular gizzard plates, all of them similar in shape and size (Fig. 60D). The radular formula is 12 x 1.0. 1 in a specimen from New Caledonia (MUSORSTOM 4 stn CC 175). The lateral teeth are hook-shaped with a number of small denticles on the single, curved cusp (Fig. 60C). REMARKS. — Comparison of the material here examined with the remaining syntype of <i>Acteocina gracilis</i> illustrated by Higo <i>et al.</i> (2001), confirms that they belong to the same species. <i>Acteocina gracilis</i> is characterized by its fusiform shell with an elongate callus on the aperture. <i>Acteocina fusiformis</i> A. Adams <i>in</i> Sowerby 1850, figured by Hori (2000b) is probably a synonym, but that determination must await further study.
description: Published as part of <i>Valdés, Ángel, 2008, Deep-sea " cephalaspidean " heterobranchs (Gastropoda) from the tropical southwest Pacific, pp. 587-792 in Mémoires du Muséum national d'Histoire naturelle 196</i> on pages 709-710