Turbonilla lactea (Linnaeus, 1758)

Høisaeter, Tore, 2014, The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review, Fauna norvegica 34, pp. 7-78 : 63

Turbonilla lactea (L., 1758)

Figure 106

Turbo lacteus L., 1758:1238

Odostomia lactea (L.) - Jeffreys 1848, 1867, 1884; Marshall 1900 (not O. lactea Friele 1874:18 )

Odostomia (Turbonilla) lactea (L.) - Monterosato 1875

Turbonilla lactea (L.) - Kobelt 1903; Ankel 1936; Nordsieck 1972; van Aartsen 1981; van Aartsen & al. 1984; Fretter et al. 1986; Smith & Heppell 1991; Peñas et al. 1996; Schander et al. 2003; Öztürk & Bakir 2013

Turbonilla (Chemnitzia) lactea (L.) - Dautzenberg & Fischer 1925

Chemnitzia lactea (L.) - Petersen 1888

Turbo elegantissimus Montagu, 1803:298

Parthenia elegantissima (Montagu) - Thompson 1844

Chemnitzia elegantissima (Montagu) - Forbes & Hanley 1850 - 51; Clark 1855 (not C. elegantissima of M. Sars 1859)

Turbonilla elegantissima (Montagu) - Monterosato 1884; Winckworth 1932; McKay & Smith 1979; Høisaeter 1986; (not T. elegantissima of Rodriguez Babio & Thiriot-Quièvreux 1975)

Type material: Linnaean collection in Uppsala .

Type locality: Mediterranean.

Material seen: British Isles - ZMBN 22253 , 5 shs ; ZMBN 28601 , 3 shs; Ouisnè Bay , Jersey, 1 sh (leg. W. Vader 1968), Madeira - ZMBN 3607 , 4 shs ; ZMBN 3642 , 1 sh .

Diagnosis: Shell: Turbonilla with fairly elongate, only slightly cyrtoconoid shell. Total shell length not exceeding 8.5 mm. Number of whorls 13 or less. Whorls evenly rounded, only slightly convex. Shell, white, delicate, thin. Sculpture consisting of 18-22, strong axial ribs, slightly S-shaped, extending from the suture to a short distance below the periphery. No spiral sculpture. Columellar fold very slight and retracted. Protoconch almost planorboid of 2 to 2.5 whorls at an angle of about 135° to the shell axis, its base completely exposed. Soft parts: Not known. Operculum: Not known.

Biology: “The snails suck fluid from the tentacles of such worms as Audouinia tentaculata and Amphitrite gracilis ” (Fretter 1951) . “Under stones and in crevices on muddy rocky shores at LWST, extending to 10 fathoms, on all coasts, Ireland; associated with Amphitrite gracilis , Cirratulus cirratus and Audouinia tentaculata . Breeding unknown” (Fretter & Graham 1962, Fretter et al. 1986).

Distribution: Not confirmed from Norway. M. Sars (1859) reported this species from Tromsø, a record that has been widely quoted, but never verified. According to Norman (1879), a record by Friele (1874) from Bergen (60.5ºN) was due to a mistake. The record of McAndrew & Barrett (1856) of frequent observations between 40-100 fathoms on gravel in Nordland and Finmark, is most certainly due to misidentifications. G.O. Sars (1878:374) included this species as one of three pyramidellids that had been included in earlier check-lists, as doubtful or obvious misidentifications. Outside Norway reported by Petersen (1888) as living in Danish waters. Found as old shells, maybe fossils, around the Firth of Forth, Scottish North Sea coast, McKay & Smith (1979). According to Fretter et al. (1986:634) “From the Mediterranean to northern Norway, but absent from Danish waters and from most of the North Sea; occasionally found off western British and Irish coasts”. The present range of this species is almost certainly not extending as far north as the Norwegian coast, the frequent citations in the literature notwithstanding. However, the species seems to have been present in the Norwegian fauna in late postglacial times ( Brögger 1901), and according to Petersen (1888), and Ankel (1936), it could still be part of the fauna in Kattegatt and the west coast of Sweden. As is evident from the citation from Fretter et al. above, the exact distribution limits of this species are hard to pinpoint due to the many misidentifications in the literature.

Remarks: There seems to be general agreement that the shells commonly called T. lactea by the continental authors and by Jeffreys, and the ones called T. elegantissima by the early British conchologists and Winckworth (1932), belong to the same species. The disagreement about the specific name stems from the uncertainty created by Linnaeus’ sketchy description of his Turbo lacteus . Forbes & Hanley (1850 -51) recommend the use of T. elegantissima on these grounds. However, apparently based on Jeffreys (1867), both Nordsieck (1972), van Aartsen (1981), and Fretter et al. (1986) (and thus Graham 1988) use T. lactea . The arguments presented are not too detailed however (van Aartsen simply states: “I consider T. lactea identical with T. elegantissima (Mont.) , and in view of priority use the name given by Linnaeus”). Schander (pers. comm to Hansson 1998) studied the types of Turbo lacteus in Uppsala, and found them to be a mixture of Rissoa parva and R. violacea . As Schander never made a formal decision on reintroducing T. elegantissima , I prefer to use the name generally accepted since the 1970ties.

Figures

Figure 106. Turbonilla lactea. Shell from Ouisné Bay, Jersey, 3.8 mm. Figure 107.Turbonilla pusilla. Left, specimen from Grimstad, East Hesnesøy, 58°20.3’N, 08°39.4’E, 30-10 m, 2.5 mm (G 28-71); right, shell from Grimstad, 900 m S of Moysanden, 58°20.9’N, 08°41.6’E, 150-50 m, 4.1 mm (G 67-71).