Ondina diaphana ( Jeffreys, 1848 )

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 47

Ondina diaphana ( Jeffreys, 1848)

Figure 80

Odostomia diaphana Jeffreys, 1848:341

Menestho (Evalea) diaphana (Jeffreys) - Winckworth 1932; Høisaeter 1986

Evalea diaphana (Jeffreys) - Fretter et al. 1986; Graham 1988

Ondina diaphana (Jeffreys) - van Aartsen 1987; Smith & Heppell 1991; Warén 1991; Schander 1995; Schander et al. 2003; Høisaeter 2009

Odostomia diaphana Jeffreys - Jeffreys 1867 ; Friele 1874; Jeffreys 1884; Marshall 1900; Warén 1980

Odostomia diaphana var. inflata Marshall - Marshall 1893

Ptychostomon (Ondina) diaphanum Jeffreys - Kobelt 1903

Odostomia obliqua Alder (in part) - Forbes & Hanley 1850 -51

Chemnitzia obliqua Alder (in part) - Clark 1855

Type material: Holotype, one shell (2.6 mm), USNM 753707 .

Type locality: Exmouth , south western Great Britain .

Material seen: Norway - Hordaland, 1 spm ; Møre og Romsdal 1 spm, 3 shs; Nordland, 1 spm.

Diagnosis: Shell: Small and slender. Shell surface smooth and shiny. See further discussion under O. perezi below. Soft parts: Mentum deeply cleft, almost to the level of the eyes. Tentacles rather long and recurve laterally at their tips. Eyes very close together. Foot rather broad and bifid posteriorly

(from Fretter et al. 1986:583. Also good photograph, their Figure 398). Operculum: Not studied.

Biology: Not known, but see O. perezi below.

Distribution: Reported from Norway by Friele (1874) from 110-130 m in Bergen (c. 60°25’N), a single specimen together with one Liostomia clavula and several Ondina divisa . This record was accepted by G.O. Sars (1878), and Norman (1879), but is not mentioned by Warén (1991). In the Zoological Museum in Bergen, a shell from Florø (61°36’N) is stated to be identified by Jeffreys. In my material only a few undisputable specimens and shells from two stations, from Møre og Romsdal county, in the outer archipelago in the southern part of the county (between 62°15’ and 62°20’N), in two dredge hauls from between 25 and 50 m, sand, gravel and stones, and large shell fragments. Further a shell from Hjertøysund, near Bodø (approx. 67°18’N, 14°21’E, 40- 30 m). My material demonstrates that it is living at least as far north as 67°20’N. Outside Norway it is recorded from western Sweden (very rare, Schander 1995), the Faroes ( Schander 1995), northern Iceland and southwards along the western British coast ( Warén 1991). According to Fretter et al. (1986) this is a southern species ranging from the Mediterranean north to the British Isles. According to van Aartsen (1987) represented in the western Mediterranean by a subspecies, O. diaphana dilucida ( Monterosato, 1884) . Peñas et al. (1996) mention Ondina dilucida from the western Mediterranean, but do not record O. diaphana as well. Öztürk et al. (2013) do not mention O. dilucida , but report five specimens of O. diaphana from the Turkish coasts.

Remarks: The main difference from the far more common O. divisa , is the complete lack of spirals and a comparatively larger body whorl. A photograph of a living specimen in Fretter et al. (1986), shows striking similarities to O. divisa (see Figure 74). Van Aartsen (1997) and Warén (1991) disagree concerning the possible synonymy of O. perezi with O. diaphana . While Warén, in line with Hylleberg Kristensen (1970), Rodriguez Babio & Thiriot-Quiévreux (1975) and several other authors, claim that the two are synonymous, van Aartsen, followed by Schander (1995), keeps them apart although based on rather indirect evidence. If the two are distinct O. diaphana should be smaller (according to van Aartsen (1987) around 1.6 mm long), more slender and more shiny. The specimen from Møre og Romsdal pictured in Figure 80 above is c. 2.5 mm long, and thus appreciably longer than the length given by van Aartsen for O. diaphana s.s. See further discussion under O. perezi below.