Anatoma amydra Geiger & Marshall, 2012, new species
Creators: name: Geiger, Daniel L.
name: Marshall, Bruce A.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Lepetellida
Anatomidae
Anatoma
Anatoma amydra

description: Anatoma amydra new species
(Figures 13–15)
Type material. Holotype (MNHN 24957: Fig. 13). 2.21 × 1.81 mm. Paratypes: New Caledonia, 22.883˚S, 167.283˚E, 570–610 m, (MNHN 24958, 18; NMNZ M.303303, 1: Fig. 14).
Type locality. Northern New Caledonia, Grand Passage, 18°49'S, 163°15'E, 600-616 m, 5 Aug 1994, N. O. Alis (BATHUS 4 stn DW914).
Etymology. Amydros, Greek for indistinct, dim, obscure. Refers to the lack of prominent features.
Description. Shell medium size (to 3.4 mm: Figs 13–14) trochiform turreted. Protoconch of 0.75 whorl, flocculent sculpture, apertural varix barely connected to embryonic cap, apertural margin shallow sinusoid. Teleoconch I of 0.66 whorl, 13–19 axial cords, spiral cord in position of selenizone. Teleoconch II of 2.75 whorls, suture little impressed, sutsel less than width of selenizone on early shell showing 1 or 2 spiral threads, 2–3× width of selenizone at apertural margin, showing approximately 6 spiral threads. Shoulder convex, many fine axial cords extending onto keels of selenizone, interstices as wide as cords at suture, twice as wide near selenizone; first spiral thread after 0.1–0.2 teleoconch II whorl, 4–10 after first whorl, 12–15 at apertural margin, evenly distributed over width of shoulder; spiral threads running over axial cords. Base barely constricted below selenizone, continuously sloping with umbilicus, dense axial cords extending onto keels of selenizone, interstices twice as wide as cords near selenizone, less than width of cords near umbilicus; approximately 25 spirals from immediately below selenizone into umbilicus, spiral threads from selenizone to mid-base, then turning into steps, increasing in strength twofold towards umbilicus. Umbilicus of moderate width, no funiculus. Aperture rounded, adumbilical portion flared, roof overhanging. Selenizone at periphery, keels moderately elevated, moderately strong; slit open, margins converging in fully-grown specimens.
Operculum (Fig. 15 D) corneous, thin, multispiral, with central nucleus.
Radula (Fig. 15 A–B). Rachidian trapezoid, central cusp slightly larger, 3–4 cusps on each side, arranged as fan. Lateral teeth 1–3 similar, apical cusp largest, 3–2 cusps on outer edge, 1 minute point at inner edge. Lateral tooth 4 reduced, hook-shaped, apical cusp largest, 1 minute point on each side. Lateral tooth 5 somewhat enlarged, apical cusp largest, 4 cusps along inner edge, 1 small point on outer edge. Inner marginal teeth with triangular tip, apical cusp largest, 1–2 cusps on inner margin, 3–5 along outer margin; outer marginal teeth spoon-shaped, with many fine bristles along edge. Radular interlock of central field moderate.
Jaw (Fig. 15 C) teardrop shaped composed of many small rhomboid platelets.
Distribution. Indo-Malayan Archipelago and Western Pacific, 250–1000 m.
Specimen records. Philippines. 12.516˚N, 120.650˚E, 92–97 m (MNHN, 7); Cervera shoal, West Palmilacan Island, 9.488˚N, 123.858˚E, 95–128 m (PANGLAO 2004 T36, MNHN, 22); Cervera shoal, 9.495˚N, 123.837˚E, 110–112 m (PANGLAO 2004 T41, MNHN, 3); Cervera shoal, 9.501˚N, 123.840˚E, 100–138 m (MNHN, 1); Cervera, 9.501˚N, 123.840˚E, 100–138 m (PANGLAO 2004 T39, MNHN, 1); Pamilacan Island, 9.501˚N, 123.918˚E, 60 m (MNHN, 1); Balicasag Island, 9.515˚N, 123.680˚E, 87–111 m (PANGLAO 2004 L613/30/ 201164, MNHN, 2); Balicasag Island, 9.515˚N, 123.687˚E, 90–110 m (MNHN, 2); Balicasag Island, 9.515˚N, 123.687˚E, 90–110 m (PANGLAO 2004 L46, MNHN, 1); Maribohoc Bay, Bohol Island, 9.600˚N, 123.750˚E, 90–200 m (PANGLAO 2004 P1, MNHN, 3); off Momo Beach, Panglao Island, 9.608˚N, 123.755˚E, 90 m (MNHN, 3); Bigag/Tabalong, Panglao Island, 9.628˚N, 123.800˚E, 62 m (PANGLAO 2004 L51–60, MNHN, 4); 15.943˚N, 121.837˚E, 473 m (AURORA 2007 CP 2749, MNHN, 1); off Aligbay Island, Bohol-Sulu sill, 8.770˚N, 123.268˚E, 624–647 m (PANGLAO 2005 CP 2384, MNHN, 1); Solomon Islands. 8.665˚S, 160.065˚E, 396–411 m (SALOMON 1 DW 1762, MNHN, 3); 9.795˚S, 160.842˚E, 53 m (MNHN, 1). New Caledonia. Grand Passage, 18.600˚S, 163.160˚E, 501 m (CONCALIS CP 3005, MNHN, 1); 18.650˚S, 163.183˚E, 550 m (MNHN, 2); 18.700˚S, 163.217˚E, 668 m (MNHN, 1); 18.816˚S, 163.250˚E, 600–616 m (MNHN, 1); 18.816˚S, 163.267˚E, 613–647 m (BATHUS 4 DW 918, MNHN, 2); 18.916˚S, 163.400˚E, 370–405 m (MNHN, 1); 18.916˚S, 163.400˚E, 344–360 m (MNHN, 15); 20.566˚S, 166.900˚E, 435 m (MNHN, 11); east coast, 20.583˚S, 165.117˚E, 380–400 m (MNHN, 1); east coast, 20.583˚N, 165.117˚E, 408–440 m (MNHN, 1); 20.583˚S, 166.883˚E, 735 m (MNHN, 1); 20.583˚S, 166.900˚E, 460 m (MNHN, 1); Loyalty Basin, 20.583˚S, 166.917˚E, 470–480 m (MNHN, 1); between Lifou and Uvea, 20.616˚N, 166.967˚E, 538 m (MNHN, 2); Loyalty Ridge, 20.633˚S, 167.117˚E, 490 m (MNHN, 1); Touho Sector, 20.733˚S, 165.233˚E, 49–59 m (MNHN, 1); Santal Bay, Lifou, 20.763˚S, 167.028˚E, 20 m (MNHN, 1); Santal Bay, Lifou, 20.763˚S, 167.028˚E, 27–31 m (MNHN, 5); Santal Bay, 20.773˚S, 167.033˚E, 20 m (MNHN, 11); Touho Sector, 20.775˚S, 165.263˚E, 45–56 m (MNHN, 1). Touho Sector, 20.781˚S, 165.230˚E, 0–1 m (MNHN, 1); Poindimie Sector, 20.816˚S, 165.317˚E, 105–110 m (MNHN, 1); Santal Bay, 20.821˚S, 167.173˚E, 25–30 m (MNHN, 4); Santal Bay, 20.873˚S, 167.133˚E, 40–60 m (MNHN, 2); Santal Bay, 20.875˚S, 167.135˚E, 5–20 m (MNHN, 7); Touho Sector, 20.878˚S, 165.325˚E, 5–25 m (MNHN, 1); Santal Bay, 20.891˚S, 167.045˚E, 12–32 m (MNHN, 10); Santal Bay, 20.920˚S, 167.012˚E, 5–30 m (MNHN, 2); east coast, 20.950˚S, 165.583˚E, 160–222 m (MNHN, 2); east coast, 20.966˚S, 165.600˚E, 302–335 m (MNHN, 5); 21.116˚S, 164.467˚E, 320–344 m (MNHN, 1); Loyalty Ridge, 21.150˚S, 167.917˚E, 310 m (MNHN, 1); Loyalty Basin, 21.533˚S, 166.483˚E, 310–315 m (MNHN, 1); Loyalty Basin, 21.533˚S, 166.483˚E, 310–315 m (MNHN, 6); 22.166˚S, 167.550˚E, 2100–2110 m (MNHN, 1); Aboré Grand Reef, Nouméa Lagoon, 22.371˚S, 166.265˚E, 12–37 m (MNHN, 2); 22.583˚S, 166.450˚E, 465–525 m (BATHUS 2 DW 739, MNHN, 50); Loyalty Basin, 22.650˚S, 166.567˚E, 570 m (MNHN, 1); 22.750˚S, 167.200˚E, 380–410 m (MNHN, 1); 22.766˚S, 167.200˚E, 390–400 m (MNHN, 1); SW of Île des Pins, 22.766˚S, 167.333˚E, 410 m (MNHN, 1); 22.783˚S, 167.233˚E, 440 m (MNHN, 20); 22.783˚S, 167.233˚E, 440 m (MNHN, 1); 22.783˚S, 167.233˚E, 440–450 m (MNHN, 30); 22.783˚S, 167.233˚E, 440 m (MNHN, 5); 22.800˚S, 167.267˚E, 444–445 m (BATHUS 2 DW 719, MNHN, 40); 22.866˚S, 167.200˚E, 400 m (MNHN, 1); 22.866˚S, 167.200˚E, 400 m (BATHUS 2 DW 729, MNHN, 1); 22.866˚S, 167.267˚E, 530–541 m (MNHN, 3); south-eastern Reef, Île des Pins, 22.875˚S, 168.208˚E, 414–436 m (MNHN, 3); 22.883˚S, 167.283˚E, 570–610 m (MNHN, 19); 22.883˚S, 167.283˚E, 570–610 m (MNHN, 1); 22.900˚S, 167.283˚E, 525–547 m (BATHUS 2 DW 721, MNHN, 5); NORFOLK 1 DW 1733, 22.933˚S, 167.250˚E, 427–433 m (MNHN, 16); 22.983˚S, 167.317˚E, 525 m (MNHN, 1); Île des Pins, SE South Reef, 22.991˚S, 168.367˚E, 491–558 m (MNHN, 3: complete). 23.000˚S, 167.250˚E, 360 m (MNHN, 1). Norfolk Ridge, 23.033˚S, 166.983˚E, 295–306 m (BATHUS 3 DW 836, MNHN, 2); 23.050˚S, 167.317˚E, 503 m (MNHN, 1); 23.050˚S, 167.317˚E, 503 m (MNHN, 10); 23.050˚S, 167.317˚E, 503 m (MNHN, 1); 23.083˚S, 167.750˚E, 680–700 m (MNHN, 1); 23.083˚S, 167.750˚E, 680–700 m (MNHN, 1); Île des Pins, 23.150˚S, 167.450˚E, 1004–1009 m (NORFOLK 2 DW 2144, MNHN, 3); Norfolk Ridge, 23.283˚S, 168.233˚E, 405–456 m (NORFOLK 2 DW 2132, MNHN, 7); Norfolk Ridge, 23.300˚S, 168.017˚E, 540 m (NORFOLK 1 DW 1722, MNHN, 10); Aztec Bank, 23.300˚S, 168.083˚E, 305–310 m (MNHN, 30); Aztec Bank, 23.300˚S, 168.100˚E, 400–402 m (MNHN, 7); Norfolk Ridge, P Bank, 23.300˚S, 168.250˚E, 266–267 m (MNHN, 5); Aztec Bank, 23.308˚S, 168.083˚E, 305–367 m (MNHN, 1); 23.308˚S, 168.083˚E, 305–367 m (MNHN, 100); 23.308˚S, 168.083˚E, 320–367 m (SMIB 8 DW 182–184, MNHN, 7); Norfolk Ridge, 23.316˚S, 168.000˚E, 601–608 m (MNHN, 50); Norfolk Ridge, 23.333˚S, 168.017˚E, 361–365 m (MNHN, 40); Norfolk Ridge, 23.333˚S, 168.267˚E, 347–1063 m (NORFOLK 1 DW 1732, MNHN, 3); Norfolk Ridge, 23.350˚S, 168.033˚E, 386–390 m (MNHN, 20); Norfolk Ridge, 23.366˚S, 168.017˚E, 381–469 m (MNHN, 20); Norfolk Ridge, 23.366˚S, 168.017˚E, 381–469 m (BATHUS 3 DW 827, MNHN, 4); 23.416˚S, 167.883˚E, 965 m (MNHN, 1); 23.583˚S, 167.200˚E, 695–705 m (MNHN, 1); Loyalty Ridge, 23.583˚S, 169.617˚E, 655 m (MNHN, 1); Norfolk Ridge, Stylaster Bank, 23.616˚S, 167.700˚E, 447–450 m (MNHN, 1); Stylaster Bank, 23.633˚S, 167.650˚E, 571–610 m (NORFOLK 2 DW 2036, MNHN, 3); S of Stylaster Bank, 23.633˚S, 167.717˚E, 433–450 m (MNHN, 21); 23.633˚S, 167.717˚E, 430–452 m (MNHN, 20); 23.650˚S, 168.000˚E, 230–360 m (BERYX 11 CH 41, MNHN, 1); Norfolk Ridge, 23.683˚S, 168.000˚E, 237–550 m (BATHUS 3 CH 802, MNHN, 1); Norfolk Ridge, 23.683˚S, 168.017˚E, 278–310 m (MNHN, 8); Norfolk Ridge, 23.683˚S, 168.017˚E, 285 m (NORFOLK 2 DW 2040, MNHN, 27); Norfolk Ridge, Jumeau East, 23.750˚S, 168.267˚E, 400–420 m (MNHN, 4); Norfolk Ridge, 23.750˚S, 168.283˚E, 410–415 m (MNHN, 1); Norfolk Ridge, Banc Introuvable, 24.650˚S, 168.633˚E, 569–616 m (MNHN, 3); Norfolk Ridge, 24.666˚S, 168.150˚E, 943–1080 m (MNHN, 2); Loyalty Ridge, 24.716˚S, 170.117˚E, 750–760 m (MNHN, 1); 24.733˚S, 168.117˚E, 430–450 m (MNHN, 100), 24.733˚S, 168.167˚E, 320–350 m (BERYX 11 DW 11, MNHN, 12); Kaimon-Maru Bank, Norfolk Ridge, 24.750˚S, 168.150˚E, 231–233 m (NORFOLK 1 DW 1675, MNHN, 6); 24.800˚S, 168.150˚E, 250–270 m (BERYX 11 DW 18, MNHN, 3); Sponge Bank, B mound, 24.916˚S, 168.367˚E, 508–532 m (MNHN, 3); Norfolk Ridge, 24.933˚S, 168.367˚E, 518–586 m (NORFOLK 2 DW 2087, MNHN, 4). Coral Sea. South Lansdowne, 21.100˚S, 160.767˚E, 569–583 m (EBISCO DW 2629, MNHN, 1). Vanuatu. NW of Tutuba Island, 15.550˚S, 167.278˚E, 92 m (SANTO 2006 DS105, MNHN, 2); E of Aoré Island, 15.604˚S, 167.150˚E, 45–101 m (SANTO 2006 EP10, MNHN, 1); NW coast of Malo Island, Palikulo Bay, 15.633˚S, 167.083˚E, 90–110 m (SANTO 2006 DB77 EP28, MNHN, 1). New Zealand. Three Kings Rise, 31.866˚S, 172.433˚E, 780–790 m (NMNZ M.173749, 9). Louisville Ridge. 41.450˚S, 164.133˚E, 950–1000 m (NMNZ M.119213, 4). Moluccas. Molucca Pass, off March Island, 0.616˚N, 127.250˚E, 796 m (USNM 312781, 1). Fiji. S of Viti Levu, 18.206˚S, 178.550˚E, 144–150 m (MNHN, 1); 19.016˚S, 178.433˚W, 395–540 m (BORDAU 1 DW 1486, MNHN, 1); 19.050˚S, 178.500˚W, 700–707 m (BORDAU 1 DW 1485, MNHN, 1). Wallis and Futuna. Wallis Island, 13.350˚S, 176.150˚W, 286 m (MNHN, 2); Wallis Island, 13.350˚S, 176.133˚W, 415–420 m (MNHN, 6). French Polynesia. Mount Ari’i Moana, Tarava Seamounts, 19.250˚S, 151.517˚W, 557–569 m (TARASOC DW 3318, MNHN, 1).
Remarks. Juvenile specimens as usual have a more lenticular overall shell shape than adults. The details of the early teleoconch permit ready identification of the species: protoconch with flocculent sculpture, teleoconch I of 0.66 whorl, with spiral in position of selenizone, and first spiral threads appearing on outer half of shoulder.
Anatoma australis (Hedley, 1903) from Australia has a longer teleoconch I (0.5 vs. 0.75 whorl), on teleoconch I has multiple spiral threads, and has more widely spaced spiral threads on the base (3 vs. 7 on sutsel of 1.5× width of selenizone).
Anatoma equatoria (Hedley, 1899) from the Indo-Malayan Archipelago has a sutsel about as wide as the selenizone at the onset of the selenizone, with axial and spiral sculpture about half as dense. Anatoma flexidentata Geiger & Sasaki, 2008, from the Indian Ocean and Western Pacific lacks the apertural varix on the protoconch, has a shorter teleoconch I (0.25 vs. 0.5 whorl), has more widely spaced axial cords particularly on the shoulder, with a sutsel that is at least 50% narrower. Anatoma pseudoequatoria (Kay, 1979) from the Indo- Malayan Archipelago to Central Pacific has a shorter teleoconch 1 (0.25 vs. 0.5 whorl), has a sutsel that is at least 50% narrower, and the intersection of the axials and spirals on the shoulder form distinct points. Anatoma japonica (A. Adams, 1862) from the Indian Ocean and the Indo-Malayan Archipelago has a very narrow umbilicus, has a narrower sutsel after one whorl (<0.5× vs.>0.5× width of selenizone, and has axial cords that are about 50% more widely spaced (interstices approximately as wide as or wider than cords vs. narrower than cords). Anatoma rainesi Geiger, 2003, from Indo-Central Pacific has a protoconch with distinct axial cords, has axial cords on teleoconch I that decrease in strength with growth, and the axial cords on the base are at least twice as widely spaced. Anatoma atlantica (Bandel, 1998) from the NW Atlantic has a much narrower sutsel (<0.5× width of selenizone), has a longer teleoconch I (0.5 vs. 0.75 whorl), and lacks a spiral cord in the position of the selenizone on teleoconch I. Anatoma proxima (Dall, 1927) from the Caribbean and the south-western Atlantic has an overall more globular shape, and has more widely spaced axial cords on the shoulder and base. Anatoma tobeyoides Geiger & Jansen, 2004, from south-eastern Australia has a protoconch with reticulate sculpture, has fine, obliquely radiating fine threads on teleoconch I, and has a narrower selenizone. Anatoma yaroni Herbert, 1986, from the Indian Ocean has a sutsel <0.5× width of selenizone, has an overall more discoidal shape, and has more widely spaced axial cords on the base.
description: Published as part of Geiger, Daniel L. & Marshall, Bruce A., 2012, New species of Scissurellidae, Anatomidae, and Larocheidae (Mollusca: Gastropoda: Vetigastropoda) from New Zealand and beyond, pp. 1-33 in Zootaxa 3344 on pages 16-21, DOI: 10.5281/zenodo.281437