Phos geminus, 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 : 153-156

Phos geminus sp. nov.

urn:lsid:zoobank.org:act:E6D82CCC-E989-4698-8A11-13390204B588

Figs 3 , 8

Phos roseatus (part) – all authors referring to African fauna [non Hinds, 1844].

Antillophos roseatus (part) – all authors referring to African fauna, including Kilburn, Marais & Fraussen 2010: 26 [non (Hinds, 1844)].

Etymology

The specific epithet of this species is derived from the Latin adjective ʻ geminus ʼ, - a, - um, meaning ʻborn togetherʼ or ʻtwinʼ, which refers to its morphological similarity to its putative sister species, P. roseatus .

Material examined

Holotype

MADAGASCAR • dd (27.9 mm long); off Fort Dauphin , ATIMO VATAE stn CP3509; 25°15′ S, 47°07′ E; depth 78–79 m; Apr. 2010; ATIMO VATAE exped.; MNHN IM-2000-35086 ( Figs 3 A–C, 8).

Paratypes

MADAGASCAR – MIRIKY Exped . • 1 dd; Mahajamba Bay , stn DW3244; 14°55′ S, 46°55′ E; depth 58–87 m; Jul. 2009; MIRIKY exped.; paratype 1; MNHN IM-2007-38263 ( Fig. 3 D–F) • 1 dd; off Naredny Banc , stn CP3287; 14°34′ S, 47°28′ E; depth 48–54 m; Jul. 2009; MIRIKY exped.; paratype 2; MNHN IM-2007-36694 • 1 dd; S of Cape Saint-Sébastien , stn CP3205; 12°38′ S, 48°26′ E; depth 60–63 m; Jun. 2009; MIRIKY exped.; paratype 3; KF 7865 • 1 dd; same collection data as for preceding; paratype 4; JR .

Other material

CHAGOS ARCHIPELAGO • 1 lv (jv); off Chagos Archipelago; deep water; ex-USSR fishing vessel; KF 4462 .

EGYPT • 4 dd (1 jv); 35 km S of Hurgada, Makadi Bay ; shallow water; May 2001; crabbed; KF 4464 .

MADAGASCAR • 1 dd; Tulear , Tulear stn 899.14; Feb. 1962; Thomassin leg.; MNHN • 3 lv; Tulear Bay , Pointe Anosy, sandflats at low tide; Von Cosel leg.; MNHN • 11 lv; off Tulear ; 2002–2004; local fishermen leg.; KF 4066. – MIRIKY Exped . • 1 dd; Leven Banc , stn CP3189; 12°30′ S, 48°18′ E; depth 346–376 m; Jun. 2009; MIRIKY exped.; MNHN • 3 dd (1 jv); Cape St. Andre, stn DW3197; 12°07′ S, 48°58′ E; depth 362–431 m; Jun. 2009; MIRIKY exped.; MNHN • 2 dd; stn DW3199; 12°06′ S, 48°57′ E; depth 527–652 m; Jun. 2009; MIRIKY exped.; MNHN • 4 dd; Cape St. Sébastian, stn CP3205; 12°38′ S, 48°26′ E; depth 60–63 m; Jun. 2009; MIRIKY exped.; MNHN • 2 dd; between Nosy Bé and Leven Banc, stn CP3206; 12°39′ S, 48°21′ E; depth 70–74 m; Jun. 2009; MIRIKY exped.; MNHN • 1 dd; stn CP3209; 12°43′ S, 48°14′ E; depth 291–353 m; Jun. 2009; MIRIKY exped.; MNHN. – off Naredny Banc, MIRIKY Exped . • 1 dd; stn DW3237; 14°31′ S, 47°25′ E; depth 50–107 m; Jul. 2009; MIRIKY exped.; MNHN • 3 dd; stn DW3238; 14°29′ S, 47°27′ E; depth 48–139 m; Jul. 2009; MIRIKY exped.; MNHN • 1 dd; stn CP3287; 14°34′ S, 47°28′ E; depth 48–54 m; Jul. 2009; MIRIKY exped.; MNHN • 9 dd; stn CP3288; 14°32′ S, 47°26′ E; depth 46–54 m; Jul. 2009; MIRIKY exped.; MNHN • 2 dd; stn CP3294; 14°29′ S, 47°27′ E; depth 263–331 m; Jul. 2009; MIRIKY exped.; MNHN • 1 dd; Mahajamba Bay , stn DW3244; 14°55′ S, 46°55′ E; depth 58–87 m; Jul. 2009; MIRIKY exped.; MNHN • 3 dd; stn CP3285; 14°47′ S, 46°58′ E; depth 512–680 m; Jul. 2009; MIRIKY exped.; MNHN • 1 dd; off Cap St. André, stn CP3256; 15°48′ S, 44°44′ E; depth 40–50 m; Jul. 2009; MIRIKY exped.; MNHN • 1 dd; stn CP3257; 15°47′ S, 44°45′ E; depth 48 m; Jul. 2009; MIRIKY exped.; MNHN. – ATIMO VATAE Exped . • 1 dd; between Lokaro and St. Luce, stn DW3515; 24°53′ S, 47°28′ E; depth 184–203 m; Apr. 2010; ATIMO VATAE exped.; MNHN • 2 dd; Cape Andavaka , stn CP3548; 25°17′ S, 46°34′ E; depth 63–66 m; Apr. 2010; ATIMO VATAE exped.; MNHN • 1 dd; Fort Dauphin , stn CP3509; 25°15′ S, 47°07′ E; depth 78–79 m; Apr. 2010; ATIMO VATAE exped.; MNHN • 2 dd; stn CP3546; 25°23′ S, 46°42′ E; depth 84–85 m; May 2010; ATIMO VATAE exped.; MNHN • 1 dd; stn CP3569; 25°05′ S, 47°05′ E; depth 69–70 m; May 2010; ATIMO VATAE exped.; MNHN • 2 lv, 8 dd (2 jv); stn CP3571; 25°08′ S, 47°09′ E; depth 77 m; May 2010; ATIMO VATAE exped.; MNHN • 2 lv, 10 dd (2 jv); stn CP3572; 25°08′ S, 47°09′ E; depth 77 m; May 2010; ATIMO VATAE exped.; MNHN • 1 dd; stn CP3573; 25°13′ S, 47°14′ E; depth 87–88 m; May 2010; ATIMO VATAE exped.; MNHN .

MOZAMBIQUE • 4 dd (1 jv); Inhaca Island , N of La Passe, INHACA stn MD13-14 ; 26°03′ S, 33°01′ E; depth 50–53 m; Nov. 2011; INHACA exped.; MNHN • 10 lv; Nacala Bay , shallow water; local collector; KF 0937 ( Fig. 3 G–J) • 2 lv; same collection data as for preceding; KF 4878 .

SEYCHELLES • 1 lv; off Mahé, deep water; 2010; trap; KF 7866. – REVES-2 Exped . • 1 dd; stn 5; 05°05′ S, 56°24′ E; depth 33 m; Aug.–Sep. 1980; REVES-2 Exped.; MNHN • 1 dd; stn 33; 04°25′ S, 54°38′ E; depth 50 m; Aug.–Sep. 1980; REVES-2 exped.; MNHN • 1 dd; stn 59; 04°11′ S, 54°54′ E; depth 50 m; Aug.–Sep. 1980; REVES-2 exped.; MNHN .

SOMALIA • 1 lv; off Ras Hafun , deep water; fishermen leg.; trawl; KF 6689 • 1 dd; Negros Bay; depth 12–25 m; 1993; dredge; KF 3304 • 2 dd; offshore, deep water; fishermen leg.; trawl; KF 2923 • 2 dd; same collection data as for preceding; KF 4152 .

SOUTH AFRICA • 1 dd; Natal, off Durban; depth 75–80 m; 1982; D. and M. Meyer; dredge; KF 4262.

UNITED ARAB EMIRATES • 6 dd; Gulf of Oman, Dibba; 25°36.07′ N, 56°20.44′ E; Feb. 2014; I. Kurtz leg.; crabbed or in sand brought from deep water with sand for beach of Radisson Blu Hotel; KF 7819 • 1 dd; same collection data as for preceding; KF 7826.

Description (holotype)

GENERAL. Shell of medium size, length 27.9 mm, moderately thin but solid ( Fig. 3 A–C). Shape slender with acute spire; whorls convex; body whorl rather stretched, with weak shoulder. Axial sculpture dominant. Colour pale brown, tending to orange, spire whorls with one moderately broad, slightly darker band, body whorl with 3 such bands, one suprasutural primary spiral cord clearly paler; axial and spiral sculpture accentuated by slightly paler knobs on top of axial ribs, varices and some axials slightly paler to white.

PROTOCONCH ( Fig. 3C ). Pale multispiral, consisting of about 4 whorls, tip usually slightly eroded or chipped, 1.5 mm high, diameter 1.2 mm; colour yellowish to pale brown, spiral bands slightly darker. First whorls smooth, glossy; third whorl with weak angulation at mid-whorl, turning into 2 spiral cords; spiral cords gradually more abapically situated, fourth whorl with 2 brown spiral cords; last 1 / 6 whorl with a few strongly opisthocline axial riblets adapically of those spiral cords. Transition to teleoconch marked by a single red-brown opisthocline axial line.

TELEOCONCH. Consisting of 7 convex whorls. First teleoconch whorl with 4 primary spiral cords, interspaces broad with 1 fine secondary spiral thread. Fifth primary spiral cord appearing along abapical suture of second teleoconch whorl, interspaces with 3 secondary spiral cords of which middle one usually slightly stronger. Middle secondary spiral cords gradually increasing in strength, resulting in 23 alternating fine and finer spiral cords on penultimate whorl, including 5 slightly stronger ones (primary spiral cords) with 3 slightly finer, but unequal in strength, secondary spiral cords in interspaces. Body whorl with 15 primary and 34 secondary spiral cords, on base towards siphonal canal growing larger. First teleoconch whorl with 11 sharp axial ribs including 1 slightly stronger varix, second and third whorl with 12 axial ribs including 1 (on second whorl) or 2 (on first whorl) slightly stronger varices. Their number only weakly increasing, penultimate whorl with 13 axial ribs, occasionaly with a single weak varix. Body whorl with 19 axial ribs, including 4 that form a broad prelabral varix.

APERTURE. Columella rather straight, gently curved towards an also straight parietal part. Adapical border of aperture broad, formed by shoulder of body whorl. Columella smooth, transition to siphonal canal with 1 weak columellar fold. Outer lip with 14 thin but moderately sharp internal lirae, extending far into aperture. Outer lip thick, edge sharp, with weak notch along siphonal canal. Aperture with siphonal canal about ⅓ of total shell length. Siphonal canal twisted, short, broad, open, on outside covered by sharp sculpture.

Distribution and habitat

This species is restricted to the western Indian Ocean along the East Africa coast, from South Africa in the south to the Red Sea in the north ( Fig. 8 ), living in sand. it is syntopic with Phos retecosus Hinds, 1844 off Chagos Archipelago (KF 1636), with P. rhodostoma Von Martens, 1880 at Nacala Bay (KF 2232, KF 3035, KF 4763) and with P. ladoboides sp. nov. ( Fig. 4 A–J) at the Seychelles (REVES-2 stn 5 and KF 6126).

Remarks

Phos geminus sp. nov. is a large species, up to 37 mm long, characterized by its slender shape with an acute spire and rather narrow body whorl and by the sharp, cancellate sculpture.

Little variability in shape and sculpture is observed. The middle secondary spiral cords may become almost as strong as the primary spiral cords (see holotype), resulting in 23 alternating fine and finer spiral cords on the penultimate whorl; in other specimens these middle secondary spiral cords may be only slightly stronger, resulting in 5 primary spiral cords with 3 finer secondary spiral cords in the interspaces (see paratype 1, Fig. 3 D–E). The number of columellar folds at the transition to the siphonal canal may vary from 1 (see holotype) to, occasionally, 2 (see paratype 1). The colour, however, may range from white and yellowish over pink ( Fig. 3 I–J) and orange or purplish to dark chocolate brown ( Fig. 3 G–H).

All authors working with African Photinae have until now referred specimens of this species to Phos roseatus Hinds, 1844 . This misidentification is listed in almost every work that covers the Indo-Pacific Ocean. However, P. roseatus from the eastern Indian Ocean and western Pacific differs from P. geminus sp. nov. in its sligtly broader shape, with axial ribs that are slightly broader on the penultimate and body whorls and fewer in number. The weak conchological differences between P. geminus sp. nov. and P. roseatus are the reason why the new species has escaped the attention of most scientists and collectors. The differences in shape and axial sculpture, however, are consistent and one is able to recognize and separate both morphotypes even with a limited amount of material.

Figures

Fig. 3. Phos geminus sp. nov. A–B. Holotype, Madagascar, off Fort Dauphin, ATIMO VATAE stn CP3509, 25°15′ S, 47°07′ E, depth 78–79 m, 27.9 mm long (MNHN IM-2000-35086). C. Apex of holotype. D–E. Paratype 1, Madagascar, Mahajamba Bay, MIRIKY stn DW3244, 14°55′ S, 46°55′ E, depth 58–87 m, 27.0 mm long (MNHN IM-2007-38263). F. Apex of paratype 1. G–H. Specimen from Mozambique, Nacala Bay, shallow water, 40.2 mm long (KF 0937). I–J. Specimen with same collection data as for preceding, 38.3 mm long (KF 0937). Scale bars: A–B, D–E, G–J = 5.0 mm; C, F = 1.0 mm.

Fig. 8. Distribution of Phos ganii sp. nov. and P. geminus sp. nov.

Fig. 4. Phos ladoboides sp. nov. A–C. Holotype, Seychelles, REVES-2 stn 31, 04°36′ S, 54°20′ E, depth 38 m, 22.4 mm long (MNHN IM-2015-482). D–E. Paratype 1, same collection data as for holotype, 15.3 mm long (MNHN IM-2000-28504). F–G. Paratype 11, Seychelles, off Mahé, in crayfish trap, deep water, 24.0 mm long (KF 6126). H. Paratype 12, same collection data as for preceding, 25.2 mm long (KF 6126). I–J. Paratype 10, same collection data as for preceding, 23.5 mm long (KF 6126). Scale bars: 5.0 mm.