Ondina warreni ( Thompson, 1845 )

Ondina warreni ( Thompson, 1845) View in CoL

Figure 78-79

Rissoa Warreni Thompson, 1845:315

Odostomia Warrenii (Thompson) View in CoL - Forbes & Hanley 1850 -51; Jeffreys 1869, 1870

Odostomia warreni (Thompson) - Marshall 1900

Odostomia warreni var. intermedia Marshall - Marshall 1893 View in CoL

Odostomia warreni var. zetlandica Marshall - Marshall 1900

Chemnitzia View in CoL Warrenii (Thompson) - Clark 1855

Ptychostomon (Ondina) warreni (Thompson) - Kobelt 1903

Menestho (Evalea) warreni (Thompson) - Winckworth 1932; Høisaeter 1986

Evalea warreni (Thompson) - Fretter et al. 1986; Graham 1988

Ondina warreni (Thompson) - van Aartsen 1987; Smith & Heppell 1991; Warén 1991; Peñas et al. 1996

Ondina cf. warreni (Thompson) - Høisaeter 2009

Odostomia obliqua var. Warrenii (Thompson) - Jeffreys 1867

Turbonilla obliqua (Alder) - Lovén 1846a, b (not Odostomia obliqua Alder, 1844 ; fide Forbes & Hanley 1850 -51)

Type material: Not known.

Type locality: Portmarnock, Dublin Bay, Ireland .

Material seen: Norway - Skagerrak, 11 spms; Shetland – 3 shs ( ZMBN 28632 Shetland, Friele don., Jeffreys det. ‘ Ondina warreni Thoms. type’)

Diagnosis: Shell: One of three Norwegian Ondina species with distinct spiral grooves, predominantly on the basal part of the shell. According to Fretter et al. (1986) the first postlarval whorl is covered with coarse spiral incisions. Best distinguished from O. divisa by the more convex whorls, deeper suture and a proportionally wider first postlarval whorl (compare Figures 72 and 78). Further, wider and with more whorls at same length, very fine overall spiral striation in addition to coarse spirals at lower part of body whorl, and somewhat wider umbilicus. Soft parts: Not known. Operculum: Not known.

Biology: Not known.

Distribution: This species has been reported twice from Norwegian waters, from Oslofjorden 75-110 m ( Jeffreys 1870) (a record apparently repeated in the Synoptic Tables in G.O. Sars 1878) and from Raunefjorden, 180 m ( Friele 1874:22). The last record was also repeated in the Synoptic Tables in G.O. Sars (1878), but retracted by Friele himself (in Norman 1879:60). Warén (1991) mentions the report in G.O. Sars (whose determination he questions), but fails to refer to Jeffreys (1870). My material supports the record of Jeffreys, but indicates that the distribution in Norway is restricted to the Skagerrak region, including Oslofjorden. Outside Norway distributed from off the north of Scotland south to Biscay according to Fretter et al. (1986). Mainly distributed along the western Irish and British coasts between 30 and 60 m on gravelly and sandy mud ( Graham 1988). Reported as the most common species of Ondina on the Atlantic coasts of southern Europe and also common in the Mediterranean ( Peñas et al. 1996, van Aartsen et al. 1998, Cachia et al. 2001, Öztürk et al. 2013).

Remarks: Available literature indicates that (at least) two different forms are known under this name. The form from Shetland ( var. zetlandica Marshall , the one at left in Figure 79) is rather different from the nominal type from further south on British and Irish coasts. This form is described as: “...an exact miniature of Limnaea stagnalis , and the dimensions are the same as those of O. obliqua , ...” ( Marshall 1900:288). The 11 specimens (referred to as O. warreni above) in my material from Skagerrak resemble Warén’s SEM-photo of O. warreni but has a higher and more dominating body whorl and aperture than that specimen.The largest shell of three also from Shetland (ZMBN 28632) is much closer in proportions to my specimens. That the species is variable is evident from the illustrations in Peñas et al. 1996 and Öztürk et al. 2013).