Run, Salmon, Run!

Salmon FAQ's

Do fish breathe air?
How do fish swim? How fast?
Can fish swim backwards?
Do all fish swim in the horizontal position?
Do fish chew their food?
What is an anadromous fish? A catadromous fish?
Why do scientists classify fish?
How is the age of a fish determined?
How long do fish live?
Do some fish give birth to living young?
Can fish distinguish color?
How many species of Pacific salmon are there?
Is it true that salmon return to spawn in freshwater areas where they were born?
what is the difference between the Atlantic salmon and the Pacific salmon?
Where do salmon go in the ocean?
What is a kokanee, or silver trout?
Do landlocked Pacific salmon die after spawning?
How large do salmon get?
What is the oldest known age of salmon and steelhead (in completed years)?
Is a steelhead a salmon or a trout?
How old are salmon when they migrate from fresh water to the ocean?
How many eggs do salmon have?
What are salmon fed in a hatchery?
How many of the young salmon released from hatcheries come back as adults?
Why are fishladders constructed?

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Can fish swim backwards?

A number can, but usually don't. Those that can are mostly members of one of the eel families.

Do all fish swim in the horizontal position?

Most do. The sea horse is among the exceptions. Another is the shrimp fish of the Indian Ocean, which congregates in schools of several individuals and swims vertically, its long tube-like snout pointing directly upward. A catfish indigenous to the Nile and other African rivers also swims in the vertical posture. Many kinds of midwater deepsea fishes swim or rest vertically.

Do fish chew their food?

Not in the human manner. Carnivorous fish use their sharp teeth to seize and hold prey while swallowing it whole or in large pieces. Bottom dwellers such as rays are equipped with large flat teeth that crush the shellfish they consume. Herbivorous fish (grazers) often lack jaw teeth, but have tooth-like grinding mills in their throats, called pharyngeal teeth. Fish would suffocate if they tried to chew, for chewing would interfere with the passage of water over the gills, necessary for obtaining oxygen.

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What is an anadromous fish? A catadromous fish?

An anadromous fish, born in fresh water, spends most of its life in the sea and returns to fresh water to spawn. Salmon, smelt, shad, striped bass, and sturgeon are common examples. A catadromous fish does the opposite - lives in fresh water and enters salt water to spawn. Most of the eels are catadromous.

Why do scientists classify fish?

Since common or colloquial names of fish vary from place to place (menhaden, for example, are known by at least three different names, and striped bass are called "stripers" in New England and "rockfish" in Chesapeake Bay), investigators would have no way of differentiating among species without a uniform naming system. The system used to name the 20,000 odd fishes known to science is called "the binomial system of nomenclature." It usually consists of a scientific name in two parts, the generic and specific names, or three parts if subspecies have been described. The words of the names are latinized regardless of the language or alphabet of the study and are frequently descriptive of a significant feature of the organism. The generic name generally applies to several species showing basic characteristics while a specific (species) name is based on a few characteristics applying to one species, separate and distinct from all others. (Example: The generic name Morone applies to white perch, white bass, and striped bass; the species names for those three fishes are Morone americanus, M. chrysops, and M. sexatilis.)

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How is the age of a fish determined?

Mainly by two methods: Growth "rings" on scales, and/or ringlike structures found in otoliths (small bones of the inner ear), are examined and counted. The rings correspond to seasonal changes in the environment and can be compared to the annual rings of tree trunks. A series of fine rings are laid down in scales for each year of life in summer, the rings grow faster and have relatively wide separations; in winter, slower growth is indicated by narrow separations between rings. Each pair of rings indicates one year. Because scale rings are sometimes influenced by other factors, scientists often use otoliths, whose ringlike structures also indicate years of life.

How long do fish live?

A few weeks or months (some of the small reef fishes) to 50 years or more (sturgeons). Longevity information is still sparse, but scientists have learned that species live 10 to 20 years in temperate waters.

Do some fish give birth to living young?

Yes, many do. These are called viviparous fishes. The sea perches of the Pacific coast, for example, give birth to living young of considerable size, sometimes one-fifth the size of the mother. Several kind of sharks produce living young

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How many eggs do salmon have?

Generally from 2,500 to 7,000 depending on species and size of fish. The chinook salmon generally produces the most and largest eggs.

What are salmon fed in a hatchery?

Vitamin-rich, high-protein diets made up of dried meals from coarse fish, animal meat excess, plant meal and bone meal, or meal from calcium-rich shells.

How many of the young salmon released from hatcheries come back as adults?

Releases of large fingerlings usually result in returns of one to five percent.

Why are fishladders constructed?

A fishladder, or fishway, often used in salmon country, is constructed to provide for up-stream passage of fish over a dam or a natural barrier that might prevent or impede progress to spawning grounds.

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How many species of Pacific salmon are there?

There are six: Chinook, coho, pink, sockeye, chum, and masu. The first five are found in North America. The masu occurs only on the Asiatic coast of the North Pacific.

Is it true that salmon return to spawn in freshwater areas where they were born?

Almost always. Some straying has been documented, but it is minor. Most spawning salmon return to the precise stream of their birth, sometimes overcoming great distances and hazardous river conditions to reach home.

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What is the difference between the Atlantic salmon and the Pacific salmon?

The Atlantic salmon is actually a member of the genus Salmo, or trout family, not a salmon, which is placed in the genus Oncorhynchus. The misnomer is so widely accepted that it would only cause confusion to rename the species. The main biological difference between the Atlantic and Pacific "salmons" is that Salmo may spawn more than once, and Oncorhynchus die soon after one spawn.

Where do salmon go in the ocean?

Contrary to earlier beliefs, many salmon from North American rivers roam far at sea in the North Pacific Ocean and the Bering Sea. The oceanic distribution of the salmon is dependent upon the species and point of origin. Sockeye and chinook salmon from northwest Alaska, for example, may migrate across the Bering Sea to areas close to Kamchatka, U.S.S.R., and south of the Aleutian Islands into the North Pacific Ocean; the sockeye also migrate eastward to the Gulf of Alaska. Salmon such as the pink, chum, and coho from central and southeast Alaska, British Columbia, ard Washington State, migrate out into the northeastern Pacific and Gulf of Alaska. Many steelhead trout from Washington and Oregon are known to migrate far at sea to areas off the Alaskan Peninsula. Some salmon migrate several thousand miles from the time they leave the rivers as juveniles until they return as adults. A chinook salmon tagged in the central Aleutian Islands and recovered a year later in the Salmon River, Idaho, had traveled about 3,500 miles; a steelhead trout tagged south of Kiska Island (western Aleutians) was recovered about six months and 2,200 miles later in the Wynoochee River, Washington.

What is a kokanee, or silver trout?

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It is the landlocked subspecies of a sockeye salmon. The kokanee spends its entire life in fresh water and usually does not attain the size of its sea-migrating cousin.

Do landlocked Pacific salmon die after spawning?

Yes. This phase of their life history is the same as their seagoing relatives.

How large do salmon get?

Weights of 100 pounds and slightly over have been reported from European countries for the Atlantic salmon; the record for the largest of the Pacific species, chinook, is 126 pounds for a fish caught on commercial gear in Alaskan waters.

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What is the oldest known age of salmon and steelhead (in completed years)?

Pacific salmon: chinook--7; sockeye--7; silver--4; chum--6; pink--2 Atlantic salmon: 8 Steelhead trout: 8

Is a steelhead a salmon or a trout?

The steelhead is a rainbow trout that migrates to sea as a juvenile and returns to fresh water as an adult to spawn. Unlike the Pacific salmon, the steelhead trout does not always die following spawning and may spawn more than once and return to the sea after each spawning.

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How old are salmon when they migrate from fresh water to the ocean?

That depends on species: Chinook--fall chinook, 3-4 months after hatch; spring chinook, 12-16 months; Coho--12-24 months; Chum--a week to a month; Sockeye--12 months to 36 months; Pink--a week to a month.

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