Sockeye salmon species "Oncorhynchus kawamurae". Sockeye salmon use patterns of limnetic feeding behavior, which encompasses vertical movement, schooling, diel feeding chronology, and zooplankton prey selectivity. They can change their position in the water column, timing and length of feeding, school formation, and choice of prey to minimize the likelihood of predation. This also ensures they still get at least the minimum amount of food necessary to survive. All of these behaviors contribute to the survivability, and therefore fitness of the salmon. Depending on location and threat of predation, the levels of aggressive feeding behavior can vary. Sockeye salmon, unlike other species of
Kokanee salmon of landlocked sockeye has occurred more than once with different kokanee populations, showing genetic differences between populations. Most evidence points to events that land-locked the lake-type sockeye (which spawns in streams and lakes, rather than tributaries like the sea-type sockeye, but is still anadromous and spends most of its adult life out at sea), which evolved into the non-anadromous form. Genetic evidence from kokanee in the Fraser River drainage and Columbia River drainage shows that ancestors of the kokanee came from the lake-type sockeye. The data also suggests that the kokanee may have evolved back into a lake-type anadromous form