|Salmon travel upstream to spawn.|
Salmon are any of the species of fish belonging to the taxonomic family Salmonidae. Although they travel thousands of miles in their lifetime, they are perhaps best known for their perilous migration upstream from the ocean to spawn in the area where they were born. They lay their eggs in a nest and generally they die immediately after spawning but other times it's weeks later.  A fry (or baby salmon) will stay in the nest until the yolk sac has been absorbed.  They are characterized by having a fatty fin (adipose fin) and scales.  Salmon makes a very tasty and rewarding meal to animals like bears as well as humans. Eating only 1-3 servings of salmon per month can change a person’s risk of heart disease. 
Salmonidae are a very diverse group of fish that have all different kinds of physical traits. Trout are characterized by an adipose fin (one containing fat or fatty) and circle shaped scales that are embedded in mucous.  Fish from the family Salmonidae have their last three vertebrae turned dorsally. They have well developed teeth and the lateral line is present. The lateral line detects vibrations in the water.  It is typical to have no scales on the sides of the tail. It is very common for members of this family to have the ability to be of either sex. This is called sexual dimorphism.  In most of these fish, they have a deeply forked tail and on others it is squared. Typically their jaw extends beyond the eye and adipose fin.  They range in size and some of the biggest, the Chinook salmon, exceed 40 pounds.  Pacific salmon usually have fewer than 13 rays in the anal fin. A salmon's color is typically determined by their stage in life. Young salmon have about 8-11 pigment marks and red spots on the lateral line. Atlantic salmon have black spots over their body. While spawning, the salmon turn a bronze and purplish color. After spawning they become so dark that sometimes they are called ‘black salmon.’ 
Salmonidae are born, start the maturing process and are typically off to the ocean until it is time to begin the return journey, to spawn. Salmon, trout, and other fish in the family Salmonidae, will return to the same stream they were born in, even if it means they must travel thousands of miles to get there.  Most fish will go through this process, but more specifically this is how the trout prepares to spawn: she makes a redd, or nest, that she will lay her eggs in. To form this hole she lies on her side and violently moves forward that in turn, produces a hole in the gravel. After laying about 100-400 eggs, she will cover the redd with gravel, and she reworks it until there is sufficient oxygen flow. A large number of the eggs will not make it. It will be 4-10 weeks  before the baby salmon, or fry , will hatch. In contrast the Chinook salmon don’t hatch until 3-5 months after being laid.  They will remain in the redd until the yolk sac is absorbed.  Fish in the family Salmonidae are called semelparity because they mate only once in a lifetime and die immediately or shortly afterwards. Sometimes they will live for a week or even up to a month after spawning in order to guard their nests and protect their eggs.  In the case of the book trout, they incubate for about 2-3 months. Once they reach 1 1/2 inches, they venture off to search for their own food. 
Salmonidae belong, naturally, to the Northern Hemisphere  and have been imported to other countries for fishing purposes.  They live in cold, clean waters together in schools.  They typically withstand temperatures from -.7 C to 27.8 C. In their lifetime, they will go to live in the sea for about 1 or 2 years (sometimes longer) before returning to their natal streams to spawn - a lifestyle known as anadromous.  Chinook salmon range from Alaska down to California. Most fish in the family salmonidae eat other fish, bugs and crustaceans. 
Fish, salmon in particular, have many benefits to the body. One serving of Chinook salmon contains more than 1/2 of the amount of protein your body needs in a day. It also contains more than 100% of your daily amount of Vitamin D as well as 83% of the omega-3 fatty acids you need. Omega-3 fatty acids are probably the most beneficial part of consuming this fish. They keep your body stabilized and are good for many different systems in your body. Overall it can help your heart by preventing erratic heart rhythms and making blood less likely to clot in arteries, while it also improves bad cholesterol. Some specific things that it does are: increase heart rate variability (HRV) which means that it reduces arrhythmia. It will lower your blood pressure to consume more fatty acids as well as lowering obesity by controlling specific hormones such as leptin. It can improve blood flow and it has anti-inflammatory qualities. Because it is an anti-inflammatory, it can prevent sunburns. Ultimately, eating more fish has been found to reduce the risk of certain cancers. If eaten 2 times a week it can reduce the risks for postmenopausal, diabetic, women. Eating a little bit of fish everyday can definitely lower the risk of coronary heart disease, and when eaten only 1-3 times per month it will lower the risk of a stroke.  Overall, eating salmon will definitely improve the health of your body.
(Thymallus arcticus )
- Family Salmonidae Tanya Dewey. Animal Diversity Web.
- Family Salmonidae Salmons and Trouts
- Family Salmonidae (Trout) Discover Life in America.
- Order Salmoniformes
- Salmon Family Salmonidae
- Salmonidae Michael Allaby. Highbeam Encyclopedia.
- Salmonidae (fish family) Enclyclopedia Brittanica.
- CHINOOK SALMON
- Chinook Salmon (Oncorhynchus tshawytscha) NOAA Office of Protected Resources.
- Salmo salar Atlantic salmon Vanessa Renzi. Animal Diversity Web.
- Salmon The World’s Healthiest Foods.