Eulimella ventricosa ( Forbes, 1844 )

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 60-61

Eulimella ventricosa ( Forbes, 1844)

Figures 96, 101-102

Parthenia ventricosa Forbes, 1844:188

Odostomia acicula var. ventricosa (Forbes) - Jeffreys 1867, 1869, 1870; Friele 1874

Odostomia (Eulimella) ventricosa (Forbes) - Monterosato 1875

Odostomia (Anisocycla) ventricosa (Forbes) - Monterosato 1880

Eulimella ventricosa (Forbes) - G.O. Sars 1878; Grieg 1888, 1897, 1898; Norman 1892; Friele & Grieg 1901; Kobelt 1903; Grieg 1913; Grieg 1914; Nordsieck 1972; van Aartsen & al. 1984; Fretter et al. 1986; Graham 1988; Smith & Heppell 1991; Warén 1991; van Aartsen 1994; Schander 1995; Peñas et al. 1996; Høisaeter 2009; Öztürk & Bakir 2013

Odostomia ventricosa (Forbes) - Jeffreys 1884; Marshall 1893, 1900

Anisocycla ventricosa (Forbes) - Monterosato 1884

Eulimella gracilis sp.n. - Jeffreys, 1847:311

Eulimella gracilis Jeffreys - Winckworth 1932 ; Fretter & Graham 1962; Rodriguez Babio & Thiriot- Quièvreux 1974; McKay & Smith 1979; Warén 1980; Høisaeter 1986

Chemnitzia acicula (Philippi) (in part) - Clark 1855

Eulimella affinis (Philippi) - Forbes & Hanley 1850 -51 (not Eulima affinis Philippi, 1844 ); McAndrew & Barrett 1856

Odostomia affinis (Philippi) - Jeffreys 1848

Eulimella polita? (Verrill, 1872) - Verrill 1882

Eulimella commutata var. ventricosa (Forbes) - Ankel 1936

Type material: Not known.

Type locality: Aegean Sea.

Material seen: Norway - Skagerrak, 4 spms, 1 sh; Norwegian Trench (85.01.08.1, 62°31.5’N, 701 m), 4 spms ; Hordaland, 13 spms, 24 shs; Sogn og Fjordane 7 spms, 12 shs ( ZMBN 1035 , 1036 , 15685 ) ; Møre og Romsdal, 7 spms, 12 shs; Nord-Trøndelag, 63 shs; Nordland, 1 spm, at least 30 shs; Troms: 2 shs ( ZMBN 21655 ); Ast. st. 78, 17/9-1970, 5 shs .

Diagnosis: Shell: Eulimella with fairly elongate, slightly cyrtoconoid shell. Total shell length not exceeding 6 mm. Number of whorls 10 or less. Shell delicate, thin, completely transparent, smooth with fine sinuous growth lines. Whorls convex and evenly rounded. Body whorl evenly rounded. Columellar fold hardly visible. Protoconch (Figure 102 top) large for genus, planorboid, only slightly inclined. Soft parts: Tentacles short, triangular, pointing laterally. Mentum long and narrow, dorsally grooved and bifid in front. Front end of foot slightly bifid. Eyes rather small (Figure 102 bottom). Pigmented mantle organ an elongated white ‘bar’ followed by a series of disjointed white, dark brown and yellow spots and blotches (Figure 102 bottom). Elongated batch of orange in area behind pigmented organ proper. Operculum: Not studied.

Biology: Not known. Mostly found somewhat deeper than E. laevis , although both are occasionally found in the same samples.

Distribution: In Norway found from Oslofjorden ( Jeffreys 1870) N to 68°N (G.O. Sars 1878), and 71°N ( Friele & Grieg 1901). Probably the commonest Eulimella -species on the Norwegian coast, and known as far north as the southern Barents Sea (70°55’N, Friele & Grieg 1901). In my material one specimen and one shell from Skagerrak, 24 specimens and an additional 125 shells from further north, the northernmost specimen is from a sample from outside Kristiansund (63°09’N, 145 m, sand), and the northernmost shell from the upper slope northwest of Andøya (69°25’N, 700- 200 m, clay mixed with fine sand and some stones). Outside Norway reported by McKay & Smith (1979) as rare on the Scottish North Sea coast, and by Fretter et al. (1986) as confined to northern and western Scotland, only empty shells found further south on the west coasts of the British Isles. Absent from the North Sea and from Danish and Swedish waters. Otherwise found scattered from the Mediterranean (e.g. the Turkish coast, Öztürk & Bakir 2013), and northwards along the European coast ( Fretter et al. 1986 and Peñas et al. 1996). Also found in the Canary Islands (van Aartsen et al. 2000).

Remarks: Long regarded (on the authority of Jeffreys) as a variety of E. laevis . However, in addition to the convincing arguments of G.O. Sars (1878) for recognizing it as a valid species, the very distinct protoconch (Figure 105 right, and Rodriguez Babio & Thiriot-Quiévreux 1974) should remove the last vestiges of doubt. The name has received some competition from E. affinis (Philippi, 1844) , and E. gracilis ( Jeffreys, 1847) (see e.g. Jeffreys 1884:363, Warén 1991 and van Aartsen 1994). Some problems still remain concerning its distinctness from E. ataktos (see above).