Born to kill: Predatory functional responses of the littoral amphipod Echinogammarus marinus Leach throughout its life history

► Field evidence that amphipod Echinogammarus marinus is predatory ► Juvenile, sub-adult and adult E. marinus feed on isopod Jaera nordmanni. ► Predatory functional responses were Type II at each life history stage. ► Large adult E. marinus also consumed smallest prey with Type II responses. ► Type II functional responses evident even when habitat was heterogeneous.