Anti-predator Defence in Three Daphnia Species

Over a two-year period, each of the three Daphnia species in two lakes with different pressure by fish and invertebrate predators exhibited different defensive reactions: predator avoidance in space (Daphnia hyalina), seasonal morphological changes (Daphnia cucullata), and a combination of both (Daphnia cristata). Body size and general susceptibility to predation, combined with predators' preferences were most likely responsible for the kind of defence in each of the three Daphnia.