Painter´s mussel
(Unio pictorum)Relationsship and features of typical shells (taxonomy)
Appearance
Shell elongated, reaching a total length of 7 - 10 cm (up to 14 cm among large lake morphs) and a height of 3 - 4 cm. The height are often less then half the total length, but the size varies greatly according to habitat. The upper and lower margins of the shell are often almost parallel. The lower margin does not bend upwards until it reaches the very elongated distal end. This gives the shell a "tongue-shaped" appearance. Colour from yellow- olive to light green. The umbonal rugae consist of a simple series of 6 nodules arranged in two radiating rows. The anterior adductor muscular impression is, compared to that of the Swollen river mussel (U. tumidus), situated closer to the anterior end. Hinge-teeth are present. The anterior lateral and cardinal teeth are thin and sharpened. In the left valve the cardinal tooth mostly is reduced to a tiny and edgy elevation on the inside of the anterior lateral tooth. The anterior and posterior laterals are high, sharpened and very long.Biology
The species inhabits both brooks, as well as streams, rivers and lakes in Sweden. But it is not abundant in water of strong current. It prefers waters that are rich to medium rich in nutrient. The species can mostly be found in shallow water to a depth of 5 - 6 m. Distribution
Not so common in Sweden. Scattered populations, that often are small and isolated, can be found from Scania in the very south to the middle part of the Country. Not present north of "Limes Norrlandicus". Huge gaps between different (isolated) populations.Photo: Håkan Holmberg
Scientific basis: Ted von Proschwitz
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