Lister's river snail
Fig. 35: While diving in Lake Zug sometimes one sees Lister's river snail (Viviparus contectus). — Nikon D200, Nikkor AF Micro 60mm, Lake Zug, Restaurant Baumgarten, 19 May 2013 Nikon D200; Δt=1/250 s; f=60 mm; f/22.0; ISO 200; 19 May 2013 11:24:22