Upstream
by Gayle Swigart
Title
Upstream
Artist
Gayle Swigart
Medium
Photograph - Photography - Photo
Description
Chum salmon make their way upstream to spawn in McLane Creek near Olympia, Washington.
Second only to Chinook salmon in adult size, chum salmon individuals have been reported up to 3.6 feet (1.1 m) and 45 pounds (20 kg). However, average weight is around 8 to 15 pounds (3.6 to 6.8 kg).
Chum salmon are best known for the enormous canine-like fangs and striking body color of spawning males (a calico pattern, with the front two-thirds of the flank marked by a bold, jagged, reddish line and the posterior third by a jagged black line). Females are less flamboyantly colored and lack the extreme dentition of the males. Ocean stage chum salmon are metallic greenish-blue along the back with black speckles. They closely resemble both sockeye and coho salmon at this stage. As chum salmon enter fresh water, their color and appearance changes dramatically. Both sexes develop a "tiger stripe" pattern of bold red and black stripes.
In order to mate, chum salmon adults migrate from a marine environment into the freshwater streams and rivers of their birth (called anadromy). They spawn only once and then die (called semelparity). Unlike most species that rear extensively in fresh water, chum salmon form schools, presumably to reduce predation.
Chum salmon spawn in the lowermost reaches of rivers and streams, typically within 62 miles (100 km) of the ocean. Spawning sites are often near springs. They migrate almost immediately after hatching to estuarine and ocean waters, in contrast to other Pacific salmonids, which migrate to sea after months or even years in fresh water.
Uploaded
November 8th, 2012
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