Talopena ’ tramieri ( Poppe, Tagaro & Dekker, 2006 ) Herbert, 2024

Herbert, David G., 2024, The Umboniinae (Mollusca: Gastropoda: Trochidae) of New Caledonia, with descriptions of two new genera and eight new species, plus an additional new species from the Bismarck Sea, European Journal of Taxonomy 973, pp. 1-143 : 87-92

‘ Talopena ’ tramieri ( Poppe, Tagaro & Dekker, 2006) comb. nov.

Figs 44–46

Pseudominolia tramieri Poppe, Tagaro & Dekker, 2006: 109 , pl. 74 figs 1–4. Type locality: Caubian Island, Philippines.

Pseudominolia tramieri – Hasegawa 2018: 122, fig. 5m –n.

Material examined

NEW CALEDONIA – Plateau Chesterfield-Bellona • 1 specimen, dead; Plateau Chesterfield-Bellona, Stn D 50; 21°04.4′ S, 158°40.7′ E; depth 70 m; Jul. 1984; CHALCAL 1 leg.; MNHN . – Lansdowne-Fairway Banks • 1 specimen, dead; Bancs Lansdowne – Fairway, Stn D 9; 20°44.5′ S, 161°02′ E; depth

75 m; Jul. 1984; CHALCAL 1 leg.; MNHN • 1 specimen, dead; Bancs Lansdowne – Fairway, Stn D 10; 20°36.09′ S, 161°05.82′ E; depth 87 m; Jul. 1984; CHALCAL 1 leg.; MNHN. – Lagon Nord • 2 specimens, living; Stn 1174; 19°21′ S, 163°14′ E; depth 53 m; 31 Oct. 1989; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 1168; 19°16′ S, 163°09′ E; depth 50 m; 30 Oct. 1989; B. RicherORSTOM leg.; MNHN • 4 specimens, living; Stn 1156; 19°10′ S, 163°13′ E; depth 55 m; 30 Oct. 1989; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Koumac • 1 specimen, dead; Chenal de la Passe de Koumac , Stn 1315; 20°40.7′ S, 164°14.7′ E; depth 66–87 m; Oct. 1993; Expédition Montrouzier leg.; sable coquillier vaseux; MNHN • 2 specimens, dead; Chenal de la Passe de Koumac , Stn 1323; 20°40.9′ S, 164°14.8′ E; depth 82–120 m; Oct. 1993; Expédition Montrouzier leg.; sable coquillier vaseux; MNHN • 1 specimen, dead; Passe de Koumac , east drop-off, Stn 1311; 20°40.4′ S, 164°14.9′ E; depth 10–60 m; Oct. 1993; Expédition Montrouzier leg.; fonds durs; MNHN • 1 specimen, dead; Passe Deverd, Stn 1322; 20°45.2′ S, 164°15.2′ E; depth 53–71 m; Oct. 1993; Expédition Montrouzier leg.; sable vaseux; MNHN. – Grande Terre, Touho • 3 specimens, living; Chenal au NE du Banc de Touho, Stn 1260; 20°44′ S, 165°14′ E; depth 49–59 m; Sep.1993; Expédition Montrouzier leg.; sable coquillier; MNHN • 2 specimens, dead; Chenal de Touho, Stn 1261; 20°46.5′ S, 165°15.75′ E; depth 45–56 m; Sep.1993; Expédition Montrouzier ; sable détritique; MNHN. – Grande Terre , Poindimié • 1 specimen, dead; Stn 788; 21°02′ S, 165°35′ E; depth 33 m; 9 Jan. 1987; B. Richer-ORSTOM leg.; MNHN • 2 specimens, dead; Stn 765; 21°14′ S, 165°42′ E; depth 35 m; 8 Jan. 1987; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Canala • 1 specimen, dead; Stn 730; 21°17′ S, 165°55′ E; depth 40–43 m; 12 Aug. 1986; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 713; 21°23′ S, 166°01′ E; depth 34–35 m; 11 Aug. 1986; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 714; 21°21′ S, 166°02′ E; depth 37–38 m; 11 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Thio • 1 specimen, dead; Stn 682; 21°34′ S, 166°19′ E; depth 36–37 m; 9 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Yaté • 1 specimen, dead; Stn 621; 22°01′ S, 166°53′ E; depth 55–56 m; 6 Aug. 1986; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 620; 22°02′ S, 166°56′ E; depth 50–52 m; 6 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Loyalty Islands • 2 specimens, dead; Lifou, Baie du Santal, ridge SE of Pointe Aimé Martin [= Acadro], Stn 1462; 20°47.1′ S, 167°03.2′ E; depth 70–120 m; 9 Nov. 2000; Atelier LIFOU 2000 leg.; dredged; MNHN .

Description ( Fig. 44 )

SHELL. Of moderate size (largest specimens 8–10 mm in diameter); spire whorls with 4–5 primary spiral cords (some intervals with a weaker intermediary cord) crossed by numerous fine, close-set, strongly prosocline axial threads. In addition, there are microscopic spiral lirae between the spiral cords; these interact with the axial threads to produce a fine, micro-granular sculpture – more obvious in some specimens than others. Base with finer, more close-set spiral sculpture. Umbilicus of moderate width and distinctive in having a strong, deep-set and relatively narrow spiral funicle that ends as a strong, tongue-shaped projection one quarter to one third of the way down columella. A deep, narrow channel separates this funicle from base of preceding whorl. A second, weaker, funicle lies just within rim of umbilicus, terminating as a more rounded projection near base of columella.

COLOUR. Pattern variable; usually pale, variously mottled with shades of yellow-ochre, with darker orange-yellow to brown blotches, particularly below suture; occasionally with a pinkish-orange wash in parts; spiral cords commonly flecked with white. Base paler and less boldly patterned; umbilicus whitish, upper funicle evidently never pigmented.

PROTOCONCH ( Fig. 45B ). Typically umboniine, diameter ±190 µm; apical beak present and confluent with terminal lip; apical bulb sculptured with an irregular, open network of threads, remainder with traces of subspiral threads; terminal lip weakly convex.

OPERCULUM ( Fig. 45C–D ). Corneous, multispiral; whorls relatively narrow, separated by a well-defined groove; peripheral fringe with faint radial striation; spiral microsculpture lacking.

RADULA ( Fig. 45E–F ). Formula ∞+ (1)+ 5+1+ 5+(1) +∞, with ± 45 transverse rows of teeth; teeth of central field reduced; rachidian base-plate broad, roundly quadrate its anterior edge recurved with vestige of shaft in centre; base-plates of inner lateral teeth expanded and bluntly rounded basally, outer anterior edge somewhat raised; outer laterals more quadrate. Innermost marginal transitional, with reduced shaft and cusp, and shouldered medial face; other marginal teeth well developed with narrow shaft and strongly recurved cusp; cusps of inner marginal teeth with large bluntly lanceolate central denticle bearing a small pointed denticle at its outer base and an even smaller, more slender one at inner base (usually not visible due to tooth overlap); marginals 3–10 with largest cusps; cusps progressively smaller thereafter, outermost ones with finely pectinate margins.

EXTERNAL ANATOMY (from rehydrated specimens). Limited detail evident; eyestalks well developed, their tips expanded and containing large black eyes; left neck-lobe digitate, digits perhaps branched; right neck-lobe well developed, margin entire, rolled to form an exhalant siphon; four micropapillate epipodial tentacles on left side, a similar number presumed on right. Epipodium and sides of foot densely speckled with pale pigmentation. Ctendium appearing bipectinate, its tip free.

Habitat

New Caledonian material mostly associated with the deeper regions of the lagoon and passes exiting the lagoon; at depths of 33–82 m (living 35–55 m).

Distribution ( Fig. 46 )

Previously known from the Philippines ( Poppe et al. 2006) and Ogasawara Islands ( Hasegawa 2018), here recorded also from the Chesterfield-Bellona Plateau, Lansdowne-Fairway Banks, Lagon Nord, Grande Terre and Loyalty Islands.

Remarks

Poppe et al. (2006) referred this species to Pseudominolia Herbert, 1992 , but did so only provisionally, pending further study. The presence of a distinct funicle in the umbilicus, and features of the radula (marginal teeth with spathulate cusps) and external anatomy (bipectinate ctenidium with unattached tip) are not consistent with referral to Pseudominolia . However, to which genus the species would be more appropriately referred is far from clear. The shell sculpture is not dissimilar to that of Kanakina glaphyrella gen. et comb. nov., but the eyestalks are long and the eyes large. The overall facies of the shell seem to be intermediate between Parminolia and Talopena . As an interim measure, pending the acquisition of molecular data, I have chosen to refer the species to Talopena , with which the radula morphology and external anatomy are largely consistent, on account of there being a strong funicle within the umbilicus and a thickened peri-umbilical band, albeit not as pronounced as in other Talopena species.

Differs from Talopena maestratii sp. nov. and T. apicina in having fewer, weaker and more widely-spaced spiral cords. In addition, the spire whorls are not so strongly shouldered and the suture is never sunken. Furthermore, in ‘ T ’. tramieri the umbilical funicle is stronger and more sharply defined, and the peri-umbilical band is less well developed. ‘ Ethalia ’ electra Herbert, 1992 from north-eastern South Africa is somewhat similar, but in that species the spiral cords are finer and more numerous, and the umbilical funicle is not as strongly developed.

Umboniinae — Group 2

Radula typically umboniine (formula ∞ +(1) +5+ 1+5 +(1) +∞), with reduced teeth in the central field, but in this group the cusps of the marginal radular teeth are not spathulate or lanceolate with a single elongate primary denticle, but rather more palmate or trigonal and the central denticle is not massively larger than the lateral denticles ( Figs 49D , 52D , 54F , 64F , 69E ). The genera Inkaba Herbert, 1992 and Pseudominolia Herbert, 1992 from the western Indian Ocean are also referable to this group.

Figures

Fig. 44. ‘Talopena’tramieri (Poppe, Tagaro & Dekker, 2006) (all MNHN). A–D. Lagon Nord, Stn 1156, height 6.0 mm, diameter 8.5 mm. E. Canala, Stn 713, height 7.3 mm, diameter 9.0 mm. F. Thio, Stn 682, diameter 7.2 mm.

Fig. 45. ‘Talopena’ tramieri (Poppe, Tagaro & Dekker, 2006) (all MNHN). A. Sculpture of apical whorls. B. Protoconch. C. Operculum. D. Detail of operculum lacking spiral microsculpture. E. Radula, entire width. F. Radula, latero-marginal transition. A–B. Canala, Stn 730. C–F. Belep, Stn 1156. Scale bars: A=0.5 mm; B, F =50 µm; C=1.0 mm; D–E =100 µm.

Fig. 46. Map of the Coral Sea showing the distribution of ‘Talopena’ tramieri (Poppe, Tagaro & Dekker, 2006) in the New Caledonian marine ecoregion.

Fig. 49. Ethaliella rhodomphala (Souverbie, 1875), radula (all MNHN). A. Entire width of radula, Koumac, Stn 1306.B. Oblique view of latero-marginal transition, Koumac, Stn 1306. C. Marginal series, Koumac, Stn KD574. D. Inner marginal teeth, Koumac, Stn 1306. Scale bars: A=50 µm; B=25 µm; C–D =20 µm.

Fig. 52. Ethminolia probabilis Iredale, 1924, operculum and radula, Twofold Bay, New South Wales (NMW 1955.158). A. Entire operculum. B. Microsculpture of operculum. C–G. Radula. Scale bars: A=0.5 mm; B=100 µm; C, E= 25 µm; D, F–G=20 µm.

Fig. 54. Ethminolia hickmanae sp. nov. A. Oblique view of apex. B. Protoconch. C–D. Operculum. E–F. Radula. A–B. Koumac, Stn KD545. C–F. Nouméa, Stn 1345 (paratype, MNHN-IM-2000-38866). Scale bars: A, C =200 µm; B =50 µm; D–E=50 µm; F =10 µm.

Fig. 64. Tylorhaphe luteopicta gen. et sp. nov. A. Oblique view of apical whorls. B. Protoconch. C. Operculum. D. Detail of operculum showing microscopic spiral sculpture. E. Radula, half row. F. Radula, latero-marginal transition. A–B. Solomon Islands, north of Malaita, Stn DW1768 (paratype, MNHN-IM-2000-38877). C–F. New Caledonia, south of Île des Pins, Stn CP4674 (paratype, MNHN- IM-2000-38876). Scale bars: A=1.0 mm; B, E =50 µm; C=0.5 mm; D= 100 µm; F =20 µm.

Fig. 69. Vanitrochus semiustus (Fischer, 1879) (all MNHN). A. Oblique view of apical whorls. B. Protoconch. C. Operculum. D. Detail of operculum to show microscopic spiral threads. E. Radula half row. F. Radula, oblique view of later-marginal transition. A–B. Koumac, Stn KD557. C–F. Ouégoa, Stn KD590. Scale bars: A= 250 µm; B, D =100 µm; C=200 µm; E= 10 µm; F =20 µm.