Ethalia anomphala, Herbert, 2024
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publication ID |
https://doi.org/ 10.5852/ejt.2024.973.2765 |
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publication LSID |
lsid:zoobank.org:pub:524B5B20-A190-4023-AC2B-7B48A725930A |
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persistent identifier |
https://treatment.plazi.org/id/714FF54E-375D-326C-FD86-FEF9FD9BFAE2 |
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treatment provided by |
Plazi |
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scientific name |
Ethalia anomphala |
| status |
sp. nov. |
Ethalia anomphala sp. nov.
urn:lsid:zoobank.org:act:8F0C73C8-973B-4710-BD6A-8D4B5262E846
Figs 2–4 View Fig View Fig View Fig
Diagnosis
Ethalia anomphala sp. nov. is characterised by its glossy, lenticular shell with completely occluded umbilicus, even in juvenile specimens. Last adult whorl less globose and not as deep as in the co-occurring E. montrouzieri , and not attaining such a large size (maximum diameter 13.5 vs 22.0 mm).
Etymology
From the Greek ‘ omphalos ’ (ΟΜφαλός) m. – a navel or umbilicus; ‘ anomphalos ’ – without a navel; in reference to the completely occluded umbilicus.
Material examined
Holotype ( Fig. 2A–D View Fig )
NEW CALEDONIA • empty shell; Plateau Chesterfield-Bellona, Stn D 56; 21°24.4′ S, 159°08.8′ E; depth 60 m; Jul. 1984; CHALCAL 1 leg.; MNHN-IM-2000-38840 GoogleMaps .
Paratypes
NEW CALEDONIA – Plateau Chesterfield-Bellona • 1 specimen, dead; Stn DW156; 19°49′ S, 158°21′ E; depth 42 m; 1 Aug. 1988; NO Coriolis -CORAIL 2 leg.; MNHN-IM-2000-38841 GoogleMaps • 3 specimens, dead; Plateau Chesterfield-Bellona, Stn D45; 20°48.93′ S, 158°30.21′ E; depth 50 m; Jul. 1984; CHALCAL 1 leg.; MNHN-IM-2000-38842 • 1 specimen, dead; same data as for holotype; MNHN- IM-2000-38843 GoogleMaps . – Lansdowne-Fairway Banks • 3 specimens, dead; Stn DW26; 20°22′ S, 161°05′ E; depth 62 m; 22 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN-IM-2000-38844 GoogleMaps • 1 specimen, dead; Bancs Lansdowne–Fairway, Stn DW02; 20°50′ S, 161°37′ E; depth 62 m; 20 Jul. 1988; NO Coriolis - CORAIL 2 leg.; MNHN-IM-2000-38845. – Belep • 1 specimen, living; Lagon Nord, Stn 487; 18°55′ S, 163°31′ E; depth 37 m; 2 Mar. 1985; B. Richer-ORSTOM leg.; MNHN-IM-2000-38846 GoogleMaps . – Grande Terre • 1 specimen, living; Nouméa, Grand Récif Sud, Stn 391; 22°46′ S, 167°01′ E; depth 65 m; 22 Jan. 1985; B. Richer-ORSTOM leg.; MNHN-IM-2000-38847 GoogleMaps .
Other material
NEW CALEDONIA – Plateau Chesterfield-Bellona • 1 specimen, dead; Plateau des Chesterfield , Stn DW144; 19°28′ S, 158°23′ E; depth 50 m; 28 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau des Chesterfield , Stn DW 125; 19°28′ S, 158°24′ E; depth 54 m; 29 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau des Chesterfield , Stn DW 14 ± 3; 19°37′ S, 158°25′ E; depth 45 m; 30 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 3 specimens, dead; Plateau des Chesterfield , Stn DW 133; 19°31′ S, 158°25′ E; depth 45 m; 30 Jul. 1988; NO Coriolis - CORAIL 2 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau Chesterfield-Bellona, Stn D46; 20°52.26′ S, 158°33.74′ E; depth 65 m; Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps • 1 specimen, dead; Stn DW 50; 19°18′ S, 158°34′ E; depth 50 m; 23 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau Chesterfield-Bellona, Stn D26; 19°10.72′ S, 158°34.95′ E; depth 48 m; Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps • 2 specimens, dead; Plateau Chesterfield-Bellona, Stn D49; 20°58.2′ S, 158°35.0′ E; depth 48 m; Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau Chesterfield-Bellona, Stn D50; 21°04.4′ S, 158°40.7′ E; depth 70 m; Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps • 1 specimen, dead; Stn DW 65; 19°15′ S, 158°41′ E; depth 62 m; 24 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau Chesterfield-Bellona, Stn DC39; 20°29.8′ S, 158°48.7′ E; depth 40 m; 23 Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps • 1 specimen, dead; Plateau des Chesterfield , Stn DW 82; 19°12′ S, 158°50′ E; depth 62 m; 25 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 2 specimens, dead; Plateau Chesterfield-Bellona, Stn D55; 21°23.9′ S, 158°59.6′ E; depth 60 m; Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps • 3 specimens, dead; Stn D62; 21°46.60′ S, 159°30.70′ E; depth 40 m; 26 Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps . – Lansdowne-Fairway Banks • 1 specimen, dead; Stn DW18; 20°44.1′ S, 161°00′ E; depth 69 m; 21 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 3 specimens, dead; Bancs LansdowneFairway, Stn DW 09; 20°53′ S, 161°35′ E; depth 62 m; 20 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 2 specimens, dead; Bancs Lansdowne – Fairway, Stn DW04; 20°52′ S, 161°37′ E; depth 64 m; 20 Jul. 1988; NO Coriolis -CORAIL 2 leg.; MNHN GoogleMaps • 1 specimen, living; Stn D6; 20°57′ S, 161°43′ E; depth 45 m; Jul. 1984; CHALCAL 1 leg.; MNHN GoogleMaps . – Belep • 1 specimen, living; Stn 1159; 19°13′ S, 163°07′ E; depth 50 m; 30 Oct. 1989; B. Richer-ORSTOM leg.; MNHN GoogleMaps . – Grande Terre, Yaté • 1 specimen, dead; Stn 618; 22°05′ S, 166°56′ E; depth 53–58 m; 6 Aug. 1986; B. Richer-ORSTOM leg.; MNHN GoogleMaps . – Grande Terre, Nouméa • 2 specimens, dead; Grand Récif Sud, Stn 545; 22°52′ S, 166°50′ E; depth 37 m; 15 Jul. 1985; B. Richer-ORSTOM leg.; MNHN GoogleMaps .
Description ( Fig. 2 View Fig )
SHELL. Of moderate size (diameter up to 13.5 mm), lenticular (H/D 0.59–0.66); teleoconch of up to 5.5 whorls; glossy throughout, except for umbilical callus and columella pillar; periphery rounded, close to mid-whorl; suture level with or slightly above periphery; base anomphalous. First teleoconch whorl with ±3 narrow spiral cords; cords broadening during second whorl and with additional intermediaries arising; sculpture appearing more like incised striae between low, broad cords at start of third whorl; subsequent whorls with only wide-set, incised striae; microscopic axial threads evident throughout, with more distinct, regularly spaced, collabral growth-lines on last adult whorl; base with fewer, more widely-spaced incised striae; striae more close-set and growth-lines more evident toward umbilicus; umbilicus entirely occluded by large callus lobe extending from parietal lip. Aperture roundly quadrate, peristome interrupted in parietal region; columella lip thickened and with indistinct transverse ridges; umbilical callus and columella lustreless with microshagreened surface; outer lip simple, strongly prosocline above periphery, orthocline below; interior smooth, nacreous in live-collected specimens.
COLOUR. Shell mottled or washed in shades of pale yellowish-white, pale orange-yellow, rose-pink, deep pink or crimson, with narrow capillary lines of alternating white and brownish dashes or chevronshaped marks; sometimes with greenish or brownish subsutural lines, spots or blotches; region bordering umbilical callus behind basal lip usually with bold reddish radiating markings; protoconch white.
DIMENSIONS. Holotype, height 8.0 mm, diameter 12.2 mm; largest specimen, diameter 13.5 mm.
PROTOCONCH ( Fig. 3A–B View Fig ). As in Ethalia montrouzieri ; diameter ± 190 µm.
OPERCULUM AND RADULA ( Fig. 3C–F View Fig ). As in Ethalia montrouzieri .
EXTERNAL ANATOMY (from rehydrated specimens). Limited detail evident; inter-tentacular region (forehead) of moderate width; snout prominent, subterminally papillate; cephalic tentacles slender; eyestalks well developed, each distally expanded and containing a large black eye; left neck-lobe digitate; right neck-lobe with entire margin and rolled to form exhalant siphon; four micropapillate epipodial tentacles on each side with a white epipodial sense organ at base of each, one also beneath each neck-lobe. Sides of foot and epipodium with dense white to cream pigmentation, particularly the metapodium. Details of ctenidial structure not clear, but anterior portion not attached.
Habitat
No substratum data recorded; dead shells at depths of 37–70 m (living specimens 37–65 m).
Distribution ( Fig. 4 View Fig )
Known only from the eastern Coral Sea (Chesterfield-Bellona Plateau and Lansdowne-Fairway Banks), the Lagon Nord and the south of Grande Terre, New Caledonia.
Remarks
Ethalia anomphala sp. nov. is a distinctive species on account of its completely occluded umbilicus, even in juvenile specimens. The co-occurring Ethalia montrouzieri also has an extensive callus largely occluding the umbilicus in adult specimens, but the umbilicus is clearly patent in juvenile and subadult specimens and even adult specimens retain a small chink medial to the base of the columella. Ethalia montrouzieri also attains a larger size (diameter up to 22.0 mm), and has a more globose profile with a deeper last adult whorl. Ethalia lampra is a smaller species (diameter up to 8.0 mm) that lacks an expanded umbilical callus and has only a small reflection at the end of the umbilical funicle. The completely occluded umbilicus of E. anomphala is reminiscent of that of species of Umbonium , but it lacks the highly specialised anatomical modifications found in species belonging to that genus.
The distribution of Ethalia anomphala sp. nov. is unusual in that it seems to be restricted to isolated reefs away from the main land mass of Grande Terre, occurring only in the extreme north and south of the latter. Lamprell & Healy (2001) observed similar distributions in some species of Spondylus Linnaeus, 1758 . This pattern may reflect a preference for ecosystems where the sediment is primarily bioclastic, with little or no terrigenous material.
| MNHN |
Museum National d'Histoire Naturelle |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.