Lucina Marchion, age 12, of Williamsport, Penn., for her question:
HOW DOES THE SALMON REPRODUCE?
Most of the salmon that make their way to dinner tables of the world come from five species that live in the coastal waters of the North Pacific Ocean. The five kinds are called the Chum, Cherry, Chinook, Sockeye and Pink salmon. A sixth species, the Atlantic salmon, is found in the North Atlantic Ocean and is more closely related to the trout than to the Pacific salmon.
Salmon is one of the world's most popular food and sport fishes. Anglers catch_millions each year for their own dining rooms, while commercial fishermen send enough of the fishes to the canneries to satisfy the many millions who can't catch their own.
Salmon are born as fresh water fish but spend part of their lives in the salt water of the oceans. However, they return to the fresh water streams of their birth as adults so they can spawn or reproduce.
Pacific salmon spawn only once and die soon afterward. Atlantic salmon may swim back to the ocean after spawning and return to fresh water to spawn as many as three or more times.
During the summer or autumn, most salmon spawn after swimming upstream up to 2,000 miles from the ocean. Often the trip takes the fishes several months.
Female salmon then lay their eggs in the gravelly beds of shallow, rippling streams. A male salmon stands guard as a female turns on her side and digs a saucer shaped nest in the gravel by swishing her tail back and forth. The female then lays her eggs in the nest, and the male fertilizes them with sperm.
The female then swims forward a short distance, digs another nest and lays more eggs.
A male and female salmon will repeat the spawning process a number of times. The gravel dug from each nest normally washes back and covers the previously laid group of eggs. The female will lay a total of between 2,000 and 10,000 eggs.
The salmon eggs hatch after three or four months and the babies hide for several weeks. Some kinds of salmon then head immediately toward the ocean, while others spend up to three or four years in fresh water. Only a small percentage eventually reach the ocean.
The salmon that reach the ocean live there from six months to five years, feeding on shrimp, squid and small fish. Some travel several thousand miles from the rivers where they were born.
Then, in one of nature's many miracles, most of the salmon return for spawning to the same streams in which they hatched.