Table 1.

Host and parasite origins.

ID		sampling site
Walby	Alaskan	Walby Lake	Alaska	61°37′N, −149°12′W
Wolf	Alaskan	Wolf Lake	Alaska	61°38′N, −149°16′W
DE	European stickleback	Großer Plöner See	Germany	54°08′N, 10°24′E
NO	European S. solidus	Lake Skogseidvatnet	Norway	60°13′N, 05°53′E