European grayling (Thymallus thymallus) just after spawning, male in front, Lake of Thun, Thun, Switzerland, March 2009  ,  BEHAVIOUR,EUROPE,FISH,FRESHWATER,GRAYLING,LAKES,MALE FEMALE PAIR,MICHEL ROGGO,OSTEICHTHYES,SWITZERLAND,TEMPERATE,UNDERWATER,VERTEBRATES,WWE  ,  Wild Wonders of Europe / Roggo