Turrancilla akontistes ( Kilburn, 1980 )

Kantor, Yuri, Strano, Giorgio, Vervaet, Fred, Weddingen, Mélanie & Puillandre, Nicolas, 2025, Revision of the genus Turrancilla (Neogastropoda: Olivoidea: Ancillariidae) in an integrative taxonomy framework, Zootaxa 5647 (5), pp. 401-434 : 407-411

publication ID	https://doi.org/10.11646/zootaxa.5647.5.1
publication LSID	lsid:zoobank.org:pub:E80FFC08-7ED4-4665-B936-FD5B0ABA1437
DOI	https://doi.org/10.5281/zenodo.15977023
persistent identifier	https://treatment.plazi.org/id/8F1D4A79-D247-487A-94DD-FE2AA56EA3C2
treatment provided by	Plazi
scientific name	Turrancilla akontistes ( Kilburn, 1980 )
status

Treatment

Turrancilla akontistes ( Kilburn, 1980) View in CoL

Figs 3 View FIGURE 3 , 4A–B View FIGURE 4 , 5 View FIGURE 5

Ancillaria lanceolata E. von Martens 1901: 23 View in CoL (not Ancillaria lanceolata Tate, 1889 View in CoL ).

Ancillaria (Turrancilla) lanceolata View in CoL —E. von Martens & Thiele 1904: 110, pl. 3, fig. 10, pl. 9 fig. 50 (radula).

Ancillus (Turrancilla) akontistes Kilburn 1980: 170 View in CoL , nom. nov. pro Ancillaria lanceolata E. von Martens, 1901 View in CoL , not Ancillaria lanceolata Tate, 1889 View in CoL .

Type locality. East Africa , Zanzibar Channel, 5°27'S, 39°18'E, depth 463 m; Valdivia stn. 245. GoogleMaps

Syntypes: ZMB Mol61070 (studied syntype SL 22.1 mm) GoogleMaps .

Sequenced material. SOLOMON ISLANDS • 2 lv; NW Santa Isabel I.; 7°39'S, 157°43'E; depth 495–650 m; SALOMON 2, stn CP2213; MNHN-IM-2007-33299, MNHN-IM-2007-33300 GoogleMaps • 1 lv; NW Santa Isabel I.; 7°42'S, 157°44'E;depth 550–682m; SALOMON 2, stn CP2214; MNHN-IM-2007-33306 GoogleMaps • 1lv; Vella Gulf, 7°48'S, 156°52'E; depth 590–600 m; SALOMON 2, stn CP2267; MNHN-IM-2007-33310 GoogleMaps • 1 lv; Guadalcanal I.; 9°25'S, 160°31'E; depth 456–551 m; SALOMONBOA 3, stn CP272; MNHN-IM-2007-36211 GoogleMaps • 1 lv; Savo; 9°12'S, 160°55'E; depth 706–722 m; SALOMONBOA 3, stn CP2777; MNHN-IM-2007-36185 GoogleMaps • 3 lv; Sealark channel; 9°37'S, 160°47'E; depth 502–621 m; SALOMONBOA 3, stn CP2850; MNHN-IM-2007-36187, MNHN-IM-2007-36188, MNHN-IM- 2007-36208 GoogleMaps • 2 lv; Kaoka Bay ; 9°40'S, 160°45'E; depth 650–725 m; SALOMONBOA 3, stn CP2858; MNHN-IM- 2007-36204, MNHN-IM-2007-36214 GoogleMaps

PAPUA NEW GUINEA • 3 lv; S of Lae, Huon Gulf; 6°56'S, 147°8'E; depth 700–740 m; BIOPAPUA stn. CP3632; MNHN-IM-2009-25006, MNHN-IM-2019-22747, MNHN-IM-2009-25007 GoogleMaps • 1 lv; Huon Gulf; 6°47'S, 147°14'E; depth 650 m; PAPUA NIUGINI, stn CP4000; MNHN-IM-2013-19870 GoogleMaps • 1 lv; NW Manam I.; 4°00'S, 144°54'E; depth 800–860 m; PAPUA NIUGINI, stn CP4078; MNHN-IM-2013-19425 GoogleMaps • 1 lv; Mambare Bay ; 7°52'S, 148°4'E; depth 575–655 m; BIOPAPUA stn. CP3729; MNHN-IM-2019-22751 GoogleMaps • 1 lv; Mambare Bay ; 7°50'S, 148°3'E; depth 895–1150 m; BIOPAPUA stn. CP3731; MNHN-IM-2019-22749 GoogleMaps

SOLOMON SEA • 1 lv; Dampier Strait; 5°35'S, 148°13'E; depth 630–870 m; PAPUA NIUGINI, stn CP4014; MNHN-IM-2013-19990 GoogleMaps • 1 lv; Induna I.; 4°35'S, 152°25'E; depth 575–616 m; PAPUA NIUGINI, stn CP4266; MNHN-IM-2013-45474 GoogleMaps • 1 lv; New Britain, Ainto Bay ; 6°10'S, 149°18'E; depth 510–743 m; MADEEP, stn CP4339; MNHN-IM-2013-46439 GoogleMaps

PHILIPPINES • 1 lv; Bohol Sea; 9°31'N, 124°01'E; depth 602–738 m; PANGLAO 2005, stn CP2350; MNHN-IM- 2007-31962 GoogleMaps • 1 lv; Bohol Sea, off Balicasag I.; 9°33'S, 124°41'E; depth 713–731 m; PANGLAO 2005, stn CP2398; MNHN-IM-2007-31967 GoogleMaps • 1 lv; Luzon I.; 15°20'N, 121°37'E; depth 593–600 m; AURORA 2007; MNHN-IM- 2007-34773. GoogleMaps

MADAGASCAR • 1 lv; off Majunga and Cap Saint-André; 15°31'S, 45°42'E; depth 760–777 m; MIRIKY, stn CP3270; MNHN-IM-2007-36849 GoogleMaps • 1 lv; off Majunga and Cap Saint-André; 15°21'S, 45°57'E; depth 780–1020 m; MIRIKY, stn CP3279; MNHN-IM-2007-36713. GoogleMaps

MOZAMBIQUE CHANNEL • 1 lv; Zambeze transect; 19°36'S, 36°47'E; depth 636 m; MAINBAZA, stn CC3154; MNHN-IM-2007-38771 GoogleMaps .

Non sequenced material. SOLOMON ISLANDS • 1 dd; NW Santa Isabel I.; 7°42'S, 157°44'E; depth 550–682 m; SALOMON 2, stn CP2214; MNHN-IM-2007-33305 GoogleMaps .

MOZAMBIQUE CHANNEL • 2 dd (badly worn); Zambeze transect; 19°35'S, 36°46'; depth 518–524 m; MAINBAZA CC3153 ( SL to 28 mm, apex broken off) .

Description. Shell of small size for the genus (up to 22 mm), oval bullet-shaped, slender. Protoconch low dome shaped, smooth, from light to distinctly brownish ( Fig. 3 I–J View FIGURE 3 ). First whorl with distinctly impressed suture, further suture overlaid by callus. Protoconch borders indistinct, rendering whorl count impossible. Spire medium to high, weakly convex in profile; primary callus moderately thick and covering all whorls except protoconch, slightly impressed at sutures; surface of callus glossy, microshagreened; secondary callus thin, extending to right-ventral side of last whorl and continuing up as fairly thin, tongue-shaped pad, reaching suture of antepenultimate whorl. Surface of secondary callus very similar to that of primary one, borders indistinct. Body whorl cloak glossy, covered by very weak and indistinct spiral striation. Olivoid groove shallow, sometimes indistinct, better seen on ending part of last whorl, terminating in very short rounded-triangular extension on outer lip. Rear edge of anterior band weak, detectable by slight elevation of shell surface due to thickening. Anterior band slightly different from shell cloak in colour, not separated into upper and lower bands. Plication plate with deep and broad groove in upper third, separating adapical largest spiral ridge, followed by three-four spiral ridges progressively weakening abapically. Columella smooth.Aperture narrow oval, acute posteriorly, widest medially; outer lip slightly thickened, slightly opisthocline, with slight, blunt labral denticle; siphonal notch moderately deep, asymmetrical. Shell from uniformly milky-white, to creamy on body whorl cloak, sometimes with slightly darker irregularly spaced axial bands, corresponding to growth lines ( Fig. 3G View FIGURE 3 ).

Operculum narrow-lanceolate, thick, spanning about 2/3 of AL, dark-brown, with terminal nucleus and prominent growth lines.

Radula ( Fig. 4A–B View FIGURE 4 ), studied in two specimens (MNHN-IM-2019-22749, SL 17.7 mm, MNHN-IM-2007-38771, SL 10.5 mm), of about 55 rows of teeth, 12-14 nascent, typical for the genus. Alary processes well developed, long, spanning about 40% of total radular membrane length. Radula about 1 mm long (11% of AL), radula membrane about 65–95 µm in width (1.2–1.1% of AL correspondingly).

Diagnostic cox-1 sites: 'A' in the site 73, 'A' in the site 169, 'G' in the site 196.

Remarks. The species exhibits some degree of variation in the shell outline as well as in the number of ridges on plication plate that can occasionally be five. In some specimens not only protoconch, but also uppermost teleoconch whorls can be orange, or the suture area can be highlighted by light orange spiral band.

Most of the specimens retain the protoconch, but in some it can be decollated together with upper teleoconch whorls.

Within the species three subclades are distinguished and recognized by ASAP as separate PSHs. Each subclade is restricted to a single geographic area. Since specimens belonging to all three subclades are morphologically very close, we consider this structuring as geographically determined. The largest clade includes the specimens collected off Solomons and Papua New Guinea. The second clade includes three specimens from the Philippines, and finally, the third one three specimens collected off Madagascar and Mozambique.

The species differs from other congeners in having milky-white or creamy small shell (not reaching 30 mm) without clear distinction in the cloak, olivoid band and with poorly differentiated anterior band.

Distribution. From east Africa to Papua New Guinea and Philippines ( Fig. 5 View FIGURE 5 ).