Jujubinus smaragdinus (Monterosato, 1880)

SSH XX – Fig. 8M–O

Trochus pumilio Philippi, 1844: 226 (no figure) (not Trochus pumilio Dillwyn, 1817).

Trochus smaragdinus Monterosato, 1880: 46–47 (no figure).

Jujubinus delpreteanus Sulliotti, 1889: 28–30 (no figure).

Diagnosis

Shell of medium size for the genus, elevated, solid, 5–7 well spaced spiral cords with not very deep interspaces with internally numerous prosocline lines and lamellae, peripheral cord evident, high height/ width ratio.

Type material

Trochus smaragdinus (lot MCZR-M-11700, label in the box: “ T. (Zizyphinus) striatus, Lin. var. smaragdina, Monts Boll. M. Ital. 1880, p. 220. C. D’Afr.!”).

Lectotype of Trochus smaragdinus Monterosato, 1880

TUNISIA • dd; Sfax; labelled “ Mirulinus smaragdinus Monts. Sfax ”; lectotype here designated; MCZR- M-11700/L

Paralectotypes of Trochus smaragdinus Monterosato, 1880

TUNISIA • 6 dd; labelled “ Mirulinus smaragdinus Monts. Sfax ”; MCZR-M-11700/P • 154 dd; unprecised locality; “ Jujubinus smaragdinus C. d’Africa ”; MCZR-M-11700/P • 4 dd; unprecised locality; labelled “ Jujubinus smaragdinus Monts. Coste d’Africa ”.

7.7 mm, Castellammare del Golfo (38°01′48.05″ N, 12°52′58.32″ E), 2 m depth. M–O. J. smaragdinus (Monterosato, 1880), CS-PM, height 7.6 mm, Borj El Hsar (34°42′38″ N, 11°09′04″ E), Kerkennah Islands, Tunisia, beached. P–R. J. delpreteanus Sulliotti, 1889, CS-PM, height 5.8 mm, Faro Lake (38°15ʹ57″ N, 15°37ʹ50″ E), Messina, Sicily, on Cymodocea nodosa Asch., 0.2 m depth. S–U. J. dispar Curini-Galletti, 1982, CS-PM, height 3.4 mm, off Málaga, Spain, 50 m depth (legit José M. Martín Pérez). V–X. J. montagui (Wood, 1828), CS-PM, height 5.5 mm, Anzio, Latium, Italy, trawled, 50 m depth. Scale bars = 2 mm.

Syntypes of Jujubinus delpreteanus Sulliotti, 1889

The original material in the Sulliotti collection is lost (M. Tancredi, Museo Civico di Storia Naturale “Giacomo Doria”, Genova, Italy, pers. com., 12 Dec. 2018).

SICILY • 5 dd; Messina, Lake Faro; labelled “ Faro di Messina ”; MCZR-M-25224-S, ex Sulliotti collection.

Other material examined

Morphotype smaragdinus

TUNISIA • 77 dd; Kerkennah, Borj El Hsar; beached; CS-PM • 5 dd; Kerkennah, West of Gharbi Island, Sidi Youssef; 0.5 m depth; lagoon bioclastic sediment; LT • 3 dd; Djerba I.; beached; LT • 1 dd; Djerba I.; 0.5 m depth; lagoon bioclastic sediment; LT • 2 lv; Djerba I., Borj Jellij; 33°53.05′ N, 10°43.58′ E; 0–1 m depth; used for DNA sequencing; MNHN-IM-2013-31801-2 • 1 lv; Djerba I., Sidi Jmour; 33°49.88′ N, 10°44.83′ E; 0–1 m depth; used for DNA sequencing; MNHN-IM-2013-31891 • 4 lv; Djerba I., Sidi Jmour; 33°49.88′ N, 10°44.83′ E; 0–1 m depth; used for DNA sequencing; MNHN-IM-2013-31988, 31998, 32000, 32113 • 2 lv; Djerba I., Sidi Solimen; 34°02′ N, 11°05′ E; 0–1 m depth; used for DNA sequencing; MNHN-IM-2013-31920, 31923.

Morphotype delpreteanus

FRANCE • 13 dd; Toulon; France; labelled “ J. propinquus ”; MCZR-M-E12/16 • 98 dd; Toulon; labelled “ J. propinquus Monts. Toulon inedito”, “ Toulon (Vimont) ”; MCZR-M-11727 • 82 dd; Toulon; labelled “ Mirulinus propinquus. M. Toulon!”; MCZR-M-11727.

SICILY • 13 dd; Messina, Lake Faro; 0.2 m depth; amidst Cystoseira; CS-PM • 2 dd; Messina, Lake Ganzirri; CS-PM • 6 lv; Messina, Lake Ganzirri; 38°15′44.5″ N, 15°37′32.0″ E; 0.5–1 m depth; used for DNA sequencing; BAU 2943.1 to BAU 2943.6 • 2 dd; Messina, Lakes (Faro and/or Ganzirri); labelled “ Trochus pumilio ”; MCZR-M-11269 • 2 dd; Messina, Lake Ganzirri; 2 m depth; LT • 20 lv; Lake Ganzirri; Messina; CS-PM.

Description (in parentheses data of the lectotype)

Morphotype smaragdinus

SHELL. Shell of medium size for the genus, height 6.8–8.0 (6.8) mm, width 4.0–4.5 (4.0) mm, height/ width ratio 1.70–1.80, conical, light. Protoconch seemingly smooth, of ca 1 whorl, 0.20–0.21 μm in width. Teleoconch of 5.5–6.5 (6.5) slightly convex whorls. Sculpture of 8–10 (8) flat, closely set abapical spiral cords of about the same strength, including the 2–3 (2) peripheral ones forming the peripheral cord, slightly shouldered, and 8–10 (8) regularly spaced, basal spiral cords large and flat. Suture well incised. Teleoconch surface covered by barely visible prosocline growth striae, irregularly set. Base convex, umbilicus closed also in juveniles, covered with a white callus. Aperture quadrangular, with the columellar callus thickened in the middle portion. Interior of the aperture whitish-greenish, nacreous.

COLOURATION. Colour of protoconch and initial teleoconch whorls whitish-greenish; remaining whorls and base greenish adorned with alternating yellowish and white patches on the spiral cords.

SOFT PARTS. Unknown for the open sea morphotype.

Morphotype delpreteanus

Epipodial tentacles translucent, densely covered by scattered tiny black (some white) speckles. Foot background creamy mottled with irregularly-shaped brown blotches (sometimes dotted), and covered by white speckles; sole white. Cephalic tentacles translucent, with a dorsal irregular and interrupted white stripe, and covered by small whitish and brownish speckles. Eye stalks brownish dorsally, creamy ventrally; eyes black. Snout dark brown, a creamy terminal band with a thin dark terminal stripe.

Distribution

Jujubinus smaragdinus as genetically tested is known with certainty from the Gulf of Gabès, Tunisia (Monterosato 1880), with living specimens at depths of 0– 1 m. We have examined samples morphologically very similar to the Tunisian material, from the Aegean and Ionian seas (see also Scuderi & Terlizzi 2012: 39, pl. 3 fig. 6, from Apulian Ionian Sea, as ‘ J. fraterculus ’), but these need to be tested genetically.

The morphotype delpreteanus occurs in the coastal lakes of Pantano Piccolo and Ganzirri (Messina, Sicily) (Sulliotti 1889; Curini-Galletti & Palazzi 1979, as Trochus pumilio Philippi, 1844; Giacobbe 2012; Scuderi et al. 2019), at depths of 0.5– 2 m. Specimens in the lot MCZR-M-11727, from “Toulon”, France (possibly the Hyères salines, including the Étang de Pesquiers) are morphologically strikingly similar to the Sicilian delpreteanus morphotype.

Remarks

We have tested Sicilian samples from a coastal lake environment, corresponding to the nominal taxon J. delpreteanus characterised by an impoverished sculpture, with denser but weaker spiral cords and a dark blackish-brown monochrome colouration. Given the relatively low genetic divergence between the Tunisian open sea form corresponding to Trochus smaragdinus, and the Sicilian coastal lake samples corresponding to J. delpreteanus (<3%), and despite the striking morphological differences, we conservatively consider them as belonging to a single species. Trochus pumilio has been considered either as a synonym of Gibbula adriatica (Philippi, 1844) by Ghisotti & Melone (1975) or as a subspecies of Jujubinus striatus (J. striatus pumilio) by Curini-Galletti & Palazzi (1979), identical with J. delpreteanus; we agree with the latter identification. However, Trochus pumilio is a junior homonym of Trochus pumilio Dillwyn, 1817, currently accepted as Obeles pumilio (Dillwyn, 1817) (Pulmonata, Geomitridae).

The open sea form of J. smaragdinus differs from J. striatus in its typical greenish-yelowish-whitish colour pattern, the smaller size, the more evident prosocline lamellae in the interspaces. It differs from J. exasperatus, J. pseudogravinae, J. vulgaris, J. gravinae, and J. dianiensis sp. nov. in its less marked sculpture in all teleoconch whorls; from J. depictus, J. sartorii, J. ruscurianus in the weaker and more regular sculpture with barely evident prosocline lamellae; from J. elenchoides in its smaller size and the fewer spiral cords; from J. superum sp. nov. in the different colouration (dark greyish-blackish in J. superum, greenish with whitish spots in J. smaragdinus). Colouration is also diagnostic with J. kyrnos sp. nov., J. fraterculus, J. gofasi sp. nov., and J. vexationis (Madeira).

See under J. delpreteanus, J. inopinatus sp. nov., J. angustibasis sp. nov., and J. dispar for comparative remarks.