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In September 2009 an extensive colony of Succinea oblonga (figure 1) was found in the Kärsämäki section (Finnish Uniform Grid coordinates 67145:2413) of the city of Turku. The species has never before been encountered in Finland. In Kärsämäki, hundreds of living S. oblonga usually appear individually in an area of about 360 x 100m. The area is mainly a lush meadow where birches, aspens and willows grow in clusters. There are also a few dirt roads and an abandoned railroad track. The flora in the habitat comprises chiefly Epilobium angustifolium, Urtica dioica, Rubus idaeus and Poaceae species. S. oblonga lives also on the edge of a parkland forest in a rather dry forest meadow area. The area of occurrence borders on fields and asphalted areas. Other land snails in the area include Arianta arbustorum, Cochlicopa lubrica, Trochulus hispidus, Vallonia excentrica, V. pulchella and Oxychilus cellarius. Other occurances have since been observed in nearby areas of the city (e.g. figure 2). The occurrences in Turku are old cultural occurrences and their origin can only be speculated. The species may have come to Finland from Sweden or Central Europe along with people in many different ways. The species may be more common in Finland than what we know; being rather small, 6–8 mm, it may not be noticed in grassy meadows.
A longer version of this article may be found in The Malacologist, 56 at http://malacsoc.org.uk/wp/wp-content/uploads/2014/09/Malacologist56sans.pdf
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figure 1: S. oblonga winters successfully in Finland and the first active individuals can be found in May. Photo: Matti Valta
figure 2: Typical habitat for S. oblonga; the Artukainen area in Turku. Photo: Matti Valta
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Succinea oblonga in Finland
Issue
25
Page
7
Species
