Bacteridium cf. carinatum (de Folin, 1870)

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 69-71

Bacteridium cf. carinatum (de Folin, 1870)

Figure 114

Eulimella carinata de Folin, 1870:209

Eulimella carinata de Folin - Schander 1994 ; van Aartsen 1994.

Bacteridium carinatum (de Folin) – Warén 1995; Peñas et al. 1996; Bogi & Galil 1997; Peñas & Rolan 2001

Anisocycla cf. carinata (de Folin) - van Aartsen et al. 2000

Type material: Two syntypes in MNHN (van Aartsen et al. 2000) .

Type locality: Cagnabac , Senegal ( Peñas & Rolan 2001) .

Material seen: Norway - Hordaland, 3 spms (Fensfjorden).

Diagnosis: Shell: Thin, loosely coiled, whorls shouldered, shiny surface with only microscopical striation, no visible columellar fold, protoconch (presumably) planorboid, upturned and almost disjoint, and easily broken.

Soft parts: Lacking eyes. Operculum: Not known.

Biology: Not known.

Distribution: First record from Norway, and never before reported from Atlantic waters north of Gibraltar.

Remarks: Three samples from the inner, deeper parts of Fensfjorden (580 m and 690 m) contained a few tiny (all less than two mm, and 0.6-0.7 mm wide) pyramidelloid shells.

Three of them were live caught, and they were without eyes. Unfortunately all had lost their protoconchs, making any attempts at identification provisional. Bacteridium carinatum (de Folin, 1870) , a species reported from the western Mediterranean ( Peñas et al. 1996) is strikingly similar to my specimens, both in the channeled suture, somewhat flattened whorls and a certain sturdyness and shape of the aperture. Bacteridium carinatum was described from Senegal and has so far not been found north of the Mediterranean coast of Spain, otherwise it lives in West Africa (south to Angola), and it has also been recorded from the Mediterranean coast of Israel ( Bogi & Galil 1997). This taxon is briefly discussed in van Aartsen (1994) and van Aartsen et al. (2000), and in Peñas & Rolán (2001). While van Aartsen et al. regard Bacteridium as an unnecessary name for striated species of the genus Anisocycla, Peñas & Rolán follow Schander (1994) and Warén (1995) in retaining Bacteridium as a close relative of Eulimella . In Figure 114 I show one of my specimens together with a specimen from Alicante, western Mediterranean, and one from Cape Verde. The illustrations I have seen of specimens from Spain and Sahara ( Peñas & Rolán 2001) are wider than the Cape Verde specimen, and I am not convinced that they are congeneric. In any case I follow Warén (1995) in keeping B. carinatum in the Pyramidellidae , as opposed to Ebala (or Anisocycla ) nitidissima which is a member of Murchisonellidae . Recent molecular work indicates that the Murchisonellidae is only distantly related to the Pyramidellidae (see Introduction above, and Dinapoli & Klussmann-Kolb 2010). The name Bacteridium (based on Eulimella praeclara Thiele, 1925 ) for this species has to my knowledge not been properly justified in the literature. The closest is this citation from Schander (1994): ‘I consider Eulimella carinata De Folin, 1870 from West Africa as belonging to the Bacteridium group’.