Ondina divisa (J. Adams, 1797 )

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 44

Ondina divisa (J. Adams, 1797)

Figures 72-74

Turbo divisus J. Adams, 1797:254 Menestho (Evalea) divisa (J. Adams) - Winckworth 1932;

Høisaeter 1986 Evalea divisa (J. Adams) - Fretter et al. 1986; Graham 1988 Ondina divisa (J. Adams) - van Aartsen 1987; Warén 1991;

Smith & Heppell 1991; Schander 1995; Peñas et al. 1996;

Schander et al. 2003; Høisaeter 2009 Turbo insculptus Montagu, 1808:129 Chemnitzia insculpta (Montagu) - Clark 1855 Odostomia insculpta (Montagu) - Alder 1848; Forbes & Hanley

1850-51; Jeffreys 1867; M. Sars 1869; Jeffreys 1870; M. Sars

1870; Friele 1874; Norman 1879; Jeffreys 1884; Marshall

1900; Bardarson 1920 Odostomia (Auriculina) insculpta (Montagu) - Collin 1880 Auriculina insculpta (Montagu) - G.O. Sars 1878; Petersen

1888; Norman 1893; Friele & Grieg 1901 Auriculina insculpta var. nobilis G.O. Sars - G.O. Sars 1878;

Schneider 1886

Ptychostomon (Ondina) insculptum (Montagu) - Kobelt 1903

Turbonilla obliqua (Alder) - Lovén 1846a, b (not Odostomia obliqua Alder, 1844 ; fide Jeffreys 1867)

Odostomia (Auriculina) obliqua (Alder) - Collin 1880 (not Odostomia obliqua Alder, 1844 ; fide Petersen 1888)

Type material: Neotype of Turbo divisus designated by Warén 1991 from a syntype (2.6 mm) of T. insculptus, BMNH 1896.8.6.37.

Type locality: Ilfracombe , Devon, Great Britain .

Material seen: Norway - Skagerrak , 26 spms ; Hordaland, 16 spms; Møre og Romsdal 26 spms; Nord-Trøndelag, 4 spms; Nordland, 100 spms.

Diagnosis: Shell: Spiral grooves separated by broad interspaces confined to the lower half of each whorl, and to the peripheral region and basal part of the last whorl. Microscopic spiral striae are found above the grooves and also between grooves. Maximum reported size, 3.8 mm. Soft parts: (Based on a juvenile from Liholmsrennen, Raunefjorden). A pale rustred pattern on head region. Eyes very close together. Mentum deeply cleft. Tentacles slightly curved and diverging, with tentacular pads. Foot bilobed posteriorly (Figure 74). Pigmented mantle organ orange with light yellow specs (Figure 74 bottom left). Operculum: (Figure 74 bottom right) oval, flat, no internal process or marginal notch.

Biology: Not known.

Distribution: Found all along the coast of Norway, at least north to 68°N (G.O. Sars 1878). In my material some 150 specimens and 200 shells from 50 stations, the northernmost are two empty (and rather eroded) shells from deep water in outer Andfjorden, (c. 69°20’N). G.O. Sars (1878) reports a variety ( var. nobilis ) from Hasvik in western Finnmark (70°30’N), which should be appreciably larger, with higher spire and deeper suture, and have much finer spiral sculpture. This is the only record from north of Lofoten, and whether it is a distinct species or only a variety is still an open question (see below). Friele & Grieg (1901) also report a specimen from Hammerfest, 20 fathoms, without specifying a particular variety. Outside Norway known from western to southern Iceland and the Faroes ( Warén 1991 and Schander 1995), the Swedish west coast and Kattegatt, the British and Irish west coasts and further south to the Bay of Biscay ( Fretter et al. 1986). Not reported further south or from the Mediterranean. Peñas et al. (1996) illustrates a specimen from Santander, the Spanish coast of the Bay of Biscay.

Remarks: The narrow and rather straight-sided first postlarval whorl might be peculiar to O. divisa (cf. Figures 72 and 78). This is the commonest species of Ondina in Norwegian waters, but several morphotypes can be distinguished in my material. The possibility of several species, or at least geographical varieties, being involved cannot be rejected (cf. Figure 73 above, showing photographs of one specimen from northern Norway, one from western Norway and one from the Skagerrak region).