Phos testaceus, Fraussen & Galindo & Rosado, 2020

Fraussen, Koen, Galindo, Lee Ann & Rosado, José, 2020, Deep-water Photinae (Gastropoda: Nassariidae) from eastern Africa, with descriptions of five new species, European Journal of Taxonomy 720, pp. 144-169 : 163-165

Phos testaceus sp. nov.

urn:lsid:zoobank.org:act:F00FF6BD-2E5A-484B-BC83-F7BE5F39DFF6

Figs 6 , 9

Etymology

The specific epithet of Phos testaceus sp. nov. is derived from the Latin adjective ʻ testaceus ʼ, meaning ʻof baked earthʼ or ʻpotteryʼ, which refers to the pale brownish colour.

Material examined

Holotype

MADAGASCAR • lv (24.0 mm long); Leven Banc , MIRIKY stn DW3213; 12°31′ S, 47°52′ E; depth 262–269 m; Jun. 2009; MIRIKY exped.; MNHN IM-2013-36722 ( Figs 6 A–D, 9).

Paratypes

MADAGASCAR • 1 lv; same collection data as for holotype; paratype 1; MNHN IM-2013-36981 – ATIMO VATAE Exped . • 1 lv; off Pointe Barrow , stn CP3584; 25°28′ S, 44°25′ E; depth 203–210 m; May 2010; ATIMO VATAE exped.; paratype 2; MNHN IM-2000-35090 ( Fig. 6 E–F) • 1 dd; same collection data as for preceding; paratype 3; MNHN IM-2000-35091 • 1 dd; same collection data as for preceding; paratype 4; KF 7864 • 1 dd; same collection data as for preceding; paratype 5; JR • 1 lv; near Manantenna , stn DW3528; 24°24′ S, 47°33′ E; depth 424–436 m; May 2010; ATIMO VATAE exped.; paratype 6; MNHN IM-2000-35093 .

Other material

MADAGASCAR • 1 dd; Campagne CREVETTIERE 1971 stn CH 13; 12°41′ S, 48°16′ E; depth 308– 314 m; 1974; Campagne CREVETTIERE exped.; MNHN. – MIRIKY Exped . • 2 lv; Leven Banc , stn DW3213; 12°31′ S, 47°52′ E; depth 262–269 m; Jun. 2009; MIRIKY exped.; MNHN • 1 dd; between Nosy Bé and Leven Banc, stn DW3214; 12°33′ S, 47°52′ E; depth 302–327 m; Jun. 2009; MIRIKY exped.; MNHN • 1 dd; Nosy Bé , stn DW3232; 13°24′ S, 47°58′ E; depth 210–310 m; Jul. 2009; MIRIKY exped.; MNHN. – ATIMO VATAE Exped . • 1 lv, 1 dd (jv); near Manantenna , stn DW3528; 24°24′ S, 47°33′ E; depth 424–436 m; May 2010; ATIMO VATAE exped.; MNHN • 2 dd; stn DW3529; 24°24′ S, 47°33′ E; depth 402–407 m; May 2010; ATIMO VATAE exped.; MNHN • 5 dd; off Pointe Barrow , stn CP3584; 25°28′ S, 44°25′ E; depth 203–210 m; May 2010; ATIMO VATAE exped.; MNHN • 1 dd; off Faux-Cap , stn DW3563; 25°37′ S, 46°18′ E; depth 347–355 m; May 2010; ATIMO VATAE exped.; MNHN • 1 dd; near Lavanono , stn CP3599; 25°45′ S, 44°29′ E; depth 122–123 m; May 2010; ATIMO VATAE exped.; MNHN .

MOZAMBIQUE • 1 dd; Inhambane–Massinga ; 23º29′ S, 35º46′ E; depth 275–325 m; J. Rosado leg.; JR ( Fig. 6 G–H) .

Description (holotype)

GENERAL. Shell of medium size, 24 mm in length, thin but solid. Shape fusiform with high spire; whorls rather convex, with weak shoulder; base stretched. Axial sculpture dominant ( Fig. 6 A–D). Colour pale brown, alternating with white to greyish-white spiral band along upper spire whorl and along base. Primary spiral cords usually brown coloured, slightly darker on axial ribs. Upper half of whorls with a single broad, brown spiral band, subsuturally usually paler. This broad band usually darker when crossing axial ribs. Body whorl with 3 brown to dark brown spiral bands. Siphonal canal paler.

PROTOCONCH ( Fig. 6D ). Multispiral, tip chipped, consisting of about 3½ whorls by estimation, 1 mm high, diameter 1.2 mm; colour white, greyish to yellowish with spiral cords of same colour. First remaining whorl well convex, smooth, glossy; from 2 nd whorl on with 2 spiral cords; spiral cords gradually more abapically situated; last half whorl with a few strongly opisthocline axial riblets adapically of spiral cords. Transition to teleoconch distinct, marked by strongly opisthocline axial line and start of teleoconch sculpture.

TELEOCONCH. Consists of 7 weakly convex whorls, laterally slightly flattened, with weak angulation below subsutural slope. First teleoconch whorl with 3 primary spiral cords, interspaces broad with 1 fine secondary spiral thread. A fine spiral thread appearing in subsutural interspace along second teleoconch whorl.Third teleoconch whorl with 3 primary spiral cords, interspaces broad, with 1 (adapical interspaces) to 3 (abapical interspaces) fine secondary spiral threads of which middle secondary spiral cords slightly stronger. Penultimate whorl with 25 spiral cords of unequal strength, interspaces broad. Body whorl with 60 such spiral cords, each fine primary spiral cord usually alternating with 3 fine secondary spiral cords, at base stronger with narrower interspaces. First teleoconch whorl with 10 fine but sharp axial ribs including 1 slightly stronger varix-like one, interspaces broad. Second whorl with 11 such axial ribs. Axial ribs growing slightly stronger, their number increasing. Penultimate whorl with 18 axial ribs, including 2 varices. Body whorl with 19 axial ribs, including 1 varix and broad prelabral varix. Fine but rather sharp, microscopic incremental lines visible in between spiral sculpture.

APERTURE. Columella concave, gently curved towards a straight parietal part, with 2 columellar folds forming a moderately sharp angulation at transition to siphonal canal, occasionally with a minute parietal denticle. Callus thin, white, glossy, forming border callus at transition to outer lip. Outer lip with 21 thin but moderately sharp internal lirae, extending far into aperture; at least 4 adapical ones with minute denticle inside outer lip. Outer lip thick, edge sharp, with weak notch along siphonal canal. Aperture with siphonal canal about 2 / 5 of total shell length. Siphonal canal short, broad, open, on outside covered by broad but flattened spiral cords.

Distribution

Known from Madagascar and Mozambique ( Fig. 9 ).

Remarks

Phos testaceus sp. nov. is characterized by its moderately broad shape, with a slightly stretched base, and the fine axial and spiral sculpture, in combination with a rather pale colour.

Phos geminus sp. nov. differs from P. testaceus sp. nov. in its slender shape with a higher spire and smaller aperture, the laterally flattened whorls, the larger axial ribs that are fewer in number, the larger spiral cords, the strongly twisted siphonal canal covered by a cancellate sculpture and the more colourful shell.

Figures

Fig. 6. Phos testaceus sp. nov. A–C. Holotype, Madagascar, Leven Banc, MIRIKY stn DW3213, 12°31′ S, 47°52′ E, depth 262–269 m, 24.0 mm long (MNHN IM-2013-36722). D. Apex of holotype. E. Paratype 2, Madagascar, off Pointe Barrow, ATIMO VATAE stn CP3584, 25°28′ S, 44°25′ E, depth 203–210 m (MNHN IM-2000-35090). F. Apex of paratype 2. G–H. Dead-collected specimen from Mozambique, Inhambane–Massinga, 23°29′ S, 35°46′ E, depth 275–325 m, 19.7 mm long (JR). Scale bars: A–C, E, G–H = 5.0 mm; D, F = 1.0 mm.

Fig. 9. Distribution of Phos ladoboides sp. nov., P. pulchritudus sp. nov. and P. testaceus sp. nov.