rocess, males can be attacked by females and other males. Larger dominant males reproduce more often than other males and, because sockeye salmon are polygynous, the dominant male can mate with many females. Some subordinate males may not have the opportunity to mate at all. (Busch, 2000; Foote, 1990; Quinn, 2005)
Sockeye salmon breed from July to October, although some members of this speices located in the southern-most point of their geographic range have been known to breed into December. When females arrive, they create a nest in the gravel in which they lay their eggs. After fertilization, eggs stay in the gravel nest for 32 to 42 days. Females produce 47 to as many as 206 offspring. Sockeye salmon are independent when hatched and are able to reproduce at 4 to 5 years of age. (Busch, 2000; Lichatowich, 1999; Moore, et al., 2007; Quinn, 2005)
The average lifespan for sockeye salmon in the wild is 4 to 5 years. The oldest salmon caught was 8 years of age. Typically, sockeye salmon die after mating. ("Longevity, ageing and life history of Oncorhynchus nerka", 2009; Groot, 1966)
Sockeye salmon are social, and they swim in runs when migrating to freshwater streams to spawn. They also establish social hierarchies, usually at times of reproduction. Typically the largest male is most dominant. (Crutchfield and Pontecorvo, 1969; Quinn, 2005)
The eyes of sockeye salmon are located on opposite sides of their head, and they thus have a greater field of vision than animals with two eyes facing forward. The spectrum of visibility of sockeye salmon includes color, from indigo to red, as well as ultraviolet light. Members of this species have nostrils and an enhanced sense of smell. This also adds to their sense of taste. Additionally, sockeye salmon have lateral lines, which detect vibrations, allowing them to hear. (Busch, 2000; Groot, 1966)
While in the ocean, sockeye salmon primarily consume zooplankton. In freshwater environments, they are known to eat insects, and, when upstream, occasionally snails. (Graynoth, et al., 1986)
Adult sockeye salmon are easily spotted and caught because of their size, and they are eaten by bears, including brown bears and black bears, and birds, such as the mew gull. Predators of frys (young sockeye salmon) include lake trout, squawfish, and mountain whitefish. Most predation occurs in streams and rivers. As frys, sockeye salmon can often escape predators because of their smaller size. Humans also consume a considerable about of sockeye salmon. (Groot and Margolis, 1991; Olson, et al., 1998; Quinn and Kinnison, 1999)
Sockeye salmon are host to a variety of parasites, which are generally found within the kidney. Most of these parasites release spores when in freshwater where excretion of water by sockeye salmon is high. These parasites include Myxidium salvelini and Parvicapsula minibicornis, both myxosporeans. Sockeye salmon also contribute to the diet of black bears and brown bears. (Higgins, et al., 1993; Jones, et al., 2004; Kent, et al., 1997)
Salmon, including sockeye salmon, are caught in and destroyed by hydroelectric dams when they attempt to swim through to spawn. This decreases salmon populations and thus availability for fishing. (Pringle, 2001)
Stephan Kennedy (author), Radford University, Karen Powers (editor), Radford University, Gail McCormick (editor), Animal Diversity Web Staff.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior end