Liostomia clavula (Lovén, 1846)

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 51-52

Liostomia clavula (Lovén, 1846)

Figures 85, 89

Turbonilla clavula Lovén, 1846a:49 Eulimella clavula (Lovén) - Forbes & Hanley 1850 -51; Jeffreys

1859 Chemnitzia clavula (Lovén) - Clark 1855 Odostomia clavula (Lovén) - Jeffreys 1867, 1870; M. Sars 1870;

Friele 1874; Jeffreys 1884; Marshall 1899 Odostomia clavulus (Lovén) - Peñas et al. 1996; Odostomia (Liostomia) clavula (Lovén) - Monterosato 1884;

van Aartsen 1987 Menestho (Liostomia) clavula (Lovén) - Winckworth 1932;

Høisaeter 1986 Liostomia clavula (Lovén) - G.O. Sars 1878; Petersen 1888;

Fretter et al. 1986; Graham 1988; Smith & Heppell 1991;

Warén 1991; Schander et al. 2003; Høisaeter 2009 Liostomia clavulus (Lovén) - Cachia et al. 2001 Ptychostomon (Liostomia) clavula (Lovén) - Kobelt 1903:109 Odostomia pistillus sp.n. - Brugnone 1873:9.

Type material: Four syntypes SMNH 1519 .

Type locality: Gullmarsfjorden, Swedish west coast.

Material seen: Norway - Skagerrak, 1 spm; Sogn og Fjordane, 1 sh ( ZMBN 16634 , Florø , 61°36’N, 60 m, Friele col. & det.) ; Møre og Romsdal 10 spms, 20 shs.

Diagnosis: Shell: Smooth and glossy, small, narrow, cylindrical. Whorls fairly convex, body whorl evenly rounded. No columellar tooth. Soft parts: Cachia et al. (2001:106) describe the soft parts of a specimen from Malta: “The specimen is colourless with flat, laterally grooved triangular tentacles. Mentum short. Eyes large, very closely set and at centre of head. Foot elongated, bilobed anteriorly and rounded posteriorly. Digestive gland brown with scattered black spots.” Soft part also described by Lovén (1846b) and Clark (1855).

Operculum: Thin, corneous, white.

Biology: According to Fretter et al. (1986:590): “This species is most reliably found in association with Pennatula and therefore on the soft bottoms on which it occurs, 30-90 m deep ( Maas 1965).” I could not, however, find any support for this association in Maas (1965). The live caught specimens in my material, all from fjords in Møre og Romsdal county, were found between 62 and 42 m, on sandy bottom.

Distribution: Three previous records from Norway. G.O. Sars (1878) reported a single shell from Lofoten (since referred to L. afzelii , see above), but found also a number of specimens near Tananger outside Stavanger (58°56’N) and a single shell in Oslofjorden. Friele (1874) reported a single specimen from Bergen (see Ondina diaphana above). As these early authors did not distinguish between L. afzelii and L. clavula some or all of these records might refer to L. afzelii . Warén (1991) confirmed its presence in Norway as he found two specimens in Korsfjorden, 150- 300 m. In my material a single specimen (and three shells) from Skagerrak, ten specimens and 16 shells in several samples from Møre og Romsdal, the northernmost from Fraenafjorden (62°50’N, 62- 50 m, sand) containing six specimens and nine shells. Outside Norway the species has been reported from the Swedish west coast, the British Isles, northern Spain and the Mediterranean ( Warén 1991). Peñas et al. (1996) confirm the presence in the western Mediterranean. Also reported from the Turkish coast (Öztürk et al. 2013).

Remarks: The opinion of van Aartsen (1987) that Odostomia pistillus Brugnone, 1873 (mainly occurring in the Mediterranean) was a narrower and smaller form of the wider and slightly more conical L. clavula was based on a misinterpretation of Lovén’s L. clavula . The examination by Warén (1991) of Lovén’s types showed that L. clavula was based on the slender form. Warén further concludes that the two forms are sufficiently distinct to justify the erection of a separate species, L. afzelii for the wide form. Van Aartsen maintained that the two are extremes of a single species ( Warén 1991), but the molecular analysis of Schander et al (2003), indicates that the two are separate species. A specimen of each are shown side by side in Figure 89. Peñas et al. (1996) and Cachia et al. (2001), use the spelling ‘ clavulus ’ rather than ‘ clavula ’. This may be because the specific name is grammatically a noun and thus the ending need not agree in gender with the generic name (ICZN Article 34.2.1). Here ‘ clavula’ is used following most other recent authors.