Anatoma turbinata (A. Adams, 1862 )

Geiger, Daniel L. & Jansen, Patty, 2004, Revision of the Australian species of Anatomidae (Mollusca: Gastropoda: Vetigastropoda), Zootaxa 415 (415), pp. 1-35 : 18-21

Anatoma turbinata (A. Adams, 1862) : Figures 9–10 , 18

Anatomus turbinata A. Adams, 1862: 347 , not illustrated.

Scissurella turbinata: Crosse, 1863: 109 .

Anatomus turbinatus: Pilsbry, 1890: 59 .

Scissurella turbinata: Thiele, 1912: 15 , pl. 2, figs. 9–10 [after a specimen in the British Museum: type?].

Schizotrochus turbinatus: Habe, 1951: 68 , pl. 11, figs. 12–13.

Anatoma turbinata: Habe & Kosuge, 1964: 4 .

Anatoma turbinata: Yu & Feng, 1996 : pl. 1, figs 1–4.

Anatoma turbinata: Okutani & Hasegawa, 2000: 37 , fig. 5.

Anatoma turbinata: Higo et al., 2001 : G82 [holotype].

Anatoma agulhasensis: Bandel, 1998: 34–35 , pl. 11, figs. 4–6. [misidentification]

Anatoma agulhasensis: Jansen, 1999: 48 , figs 1–3. [misidentification]

not Scissurella turbinata: Yokoyama , 19??: Moll. Coral­Bed: 35–36, pl. 5, fig. 21 [is Sci. staminea. Fide Oyama, 1973: 10).

? Anatoma jacksoni: Bandel, 1998: 33–34 , pl. 11, fig. 1. [most likely a finer sculptured A. turbinata ].

Type material. HOLOTYPE (BMNH 1874.5.19.62. Higo et al., 2001: G82), 2.5 mm.

Type locality. Mino­sima , [ Japan] 63 fms. [= 115 m] (OD) .

Etymology. Turbinatus: Latin adjective: that which whirls; whirlwind, tornado; spinning top; spiral. Referring to the high spired shell shape.

Description. Shell turreted, medium size (2.4 mm), as high as wide, or wider. Protoconch of 3/4 whorls, flocculant sculpture, varix present, not connecting to embryonic cap. Teleoconch I of slightly more than 0.5 whorls, axial sculpture strong, spiral rib in position of selenizone. Teleoconch II up to 3 1/4 whorls (1.7 mm shell), axials stronger than spirals, approximately 85 axials on body whorl, 8 spirals on shoulder at aperture, at intersection of axials and spirals minute raised tubercles. Shoulder of undulating profile. On base spirals increase in strength from selenizone to umbilicus to become as strong as axials; intersections of axials and spirals form weak nodules; strong spiral groove beneath selenizone. Umbilicus continuously sloping from base, wide deep, with internal sill. Aperture subquadratic rounded, only flared toward umbilicus. Selenizone at periphery, above center of whorl, keels strong, growth marks not coordinated with axials.

Differential diagnosis. Anatoma turbinata is the only high­spired member of Anatomidae in Australia. Additionally, A. turbinata lacks the funicular strand in the umbilicus found in A. funiculata n. sp. and A. aupouria . Anatoma agulhasensis from South Africa is distinctly higher than wide, has stronger spirals on the shoulder, has a less distinct spiral groove beneath the selenizone, and the aperture is more rounded. Anatoma jacksoni (Melvill, 1904) from the Indian Ocean has fewer axials, and is otherwise rather similar to A. agulhasensis . In comparison to A. turbinata , A. jacksoni lacks the apertural varix of the protoconch and is less turreted, so that the suture is placed in the upper third of the previous whorl, whereas in A. turbinata the suture is placed in the lower half of the previous whorl, below a well­developed spiral rim.

Distribution. WA (Bunbury: 33°S, 114°E) to NT (Arafura Sea: 8°N, 135°E), Indonesia, South China Sea, southern Japan, Tonga, 75–274 m (shells only).

Specimen Records

NT. 108 m, Arafura Sea, ca 95 ml N Cobourg Peninsula, 9.75S, 132.067E ( AMS C.402770, 2) . 135 m, Arafura Sea, ca 110 ml N of Melville Island , 9.567S, 131.367E ( AMS C.402769, 1; AMS C.402772, 1) . 100 m, Arafura Sea, 365 km N of Milingimbi Island, Arnhem Land , 8.8S, 134.967E ( AMS C.402771, 1) . 82 m, Arafura Sea, N of Wessel Islands , 8.6S, 135.133E ( AMS C.402668, 1; AMS C.402768, 2) . 75 m, Arafura Sea, ca. 330 km NW of Wessel Islands , 8.433S, 135.367E ( AMS C.402663, 1) . 132 m, Arafura Sea, ca 210 ml NE Croker Island, 8.3S, 133.967E ( AMS C.402662, 2) .

WA. 156 m, W of Bunbury , 33.05S, 114.733E ( AMS C.402763, 1) . 146 m, W of Rottnest Is , 32S, 115.25E ( AMS C.402767, 1) . 150 m, Direction Bank, off Rottnest Island , 31.735S, 115.177E ( AMS C.402762, 1) . 155 m, off Rottnest Is , 31.732S, 115.158E ( AMS C.402764, 1) . 124 m, off Rottnest Is , 31.718S, 115.208E ( AMS C.402765, 1) . 150 m, off Rottnest Island , 31.703S, 115.137E ( AMS C.402667, 1) . 140 m, Direction Bank, off Rottnest Is , 31.627S, 115.133E ( AMS C.402664, 1) . 274 m, NW of Beagle Is , 29.717S, 114.283E ( AMS C.402666, 2) . 264 m, off North West Cape, 22.5S, 113.597E ( AMS C.402766, 1) . 190 m, off North West Cape, 22.387S, 113.677E ( AMS C.402761, 2) . 194 m, North West Shelf , ca 100 ml NW of Broome, 16.967S, 120.783E ( AMS C.402665, 1) .

Tonga. 260 m, SE of Tongatapu, 21.345°S, 175.042°W, ( AMS 402648 , 1 ) .

Literature Records. Satonda, Indonesia [8.1°S, 117.75°E]. South China Sea ( Bandel, 1998: misidentified as A. agulhasensis ) .

Remarks. The Australian specimens of A. turbinata have so far been misidentified as A. angulhasensis , a South African species. Anatoma jacksoni (Melvill, 1904) has been listed from Satonda, Indonesia, by Bandel (1998). The illustrated specimen does not agree with material from the Indian Ocean ( Yaron, 1983: pl. 4), and most likely is A. turbinata with more tightly spaced and numerous axials and spirals, also misidentified by Bandel (1998) as A. agulhasensis . The common characters of Bandel’s “ A. jacksoni ” and A. turbinata are the position of the suture in the lower half of the previous whorl and below a distinct spiral rim; the protoconch was not illustrated and no apical view was provided.

Figures

FIGURE 9. Anatoma turbinata. AMS C.402664. Direction Bank, off Rottnest Island, WA, Australia. Scale bar shell = 200 µm. Scale bar protoconch = 50 µm.

FIGURE 10. Anatoma turbinata. Protoconchs of A–C eroded, scale bars = 200 µm. A. AMS C.402663. Arafura Sea, ca. 330 km NW of Wessel Island, NT, Australia. B. AMS C.402662. Arafura Sea, ca 210 miles NE Croker Island, NT, Australia. C. AMS C.402665. North West Shelf, ca 100 miles NW of Broome, WA, Australia. D. Protoconch profile of A. E–F. AMS C.402648. 260 m, SE of Tongatapu, Tonga. Scale bars D–F= 50 µm.

FIGURE 18. Distribution maps of Australian species of Anatomidae. Circle with star: type locality. Solid dots: specimen records. Squares: literature records.