Stephan of the Karlsruhe University of Education holds calico crayfish (Orconectes immunis) in Rheinstetten...
Andreas Stephan of the Karlsruhe University of Education holds calico crayfish (Orconectes immunis) in Rheinstetten, Germany, August 9, 2018. The University of Education examines the habitat conditions of the calico crayfish in southwest Germany. REUTERS/Ralph Orlowski