Zebra mussels
Fig. 66: Zebra mussels (Dreissena polymorpha) covering a sunken branch. — Nikon D200, Nikkor AF Micro 60mm, 2 x Sea&Sea YS-110α, Hergiswil, Lopper, Lake Lucerne, 29 July 2012 Nikon D200; Δt=1/250 s; f=60 mm; f/16.0; ISO 200; 29 July 2012 09:44:41