Salmon are an incredible fish species, and they always seem to amaze.
We may think we know salmon, if only because it is one of the most popular fish on restaurant menus, at wedding halls, or in grocery stores and is frequently eaten by people who have never been on a fishing boat in their lives. However, this unique race of vibrant pink fish is actually a bit more surprising than you might think. Read on to learn a few things about salmon you might not have known before.
View the slide show for some facts you likely didn't know.
1. They are one of the few anadromous species in the world
Most anglers know that salmon can be fished in both saltwater and freshwater. However, fewer among our fishing ranks know that salmon are among the only anadromous species in the world, meaning that they spend part of their life in freshwater and part of it in saltwater.
This two-pronged existence is more complicated than simply swimming from a freshwater stream into the wide-open expanse of the ocean. Due to the chemical differences that exist between freshwater and saltwater, salmon have to put their bodies through substantial metabolic changes every single time they migrate from one to another. These changes occur on both ends of salmon migratory patterns, and are a sign of the salmon's remarkable ability to adapt to changing environments.
2. The average salmon travels the distance of a marathon every single day
Different sources have different opinions about how far a salmon travels in a day, but most estimates point to the average being somewhere around 30 miles per day. In other words, the average salmon travels the distance of a marathon every single day. Since we are lucky to accomplish a distance like that on foot only once in a great while, you have to marvel at the sheer endurance of salmon. Furthermore, much of this swimming is done upstream and is waged against competing currents. Talk about an athletic challenge.
3. Only a small percentage of salmon ever stray permanently from home
While the average salmon travels many miles in any given day - and may even cover hundreds or thousands of miles in its full trip to and from the ocean - the fish almost always finds his or her way home eventually. It's fairly common knowledge that salmon eventually return to the river or streambed where they were born to spawn. It also figures that out of the countless salmon that are born and travel to the ocean each year, not all of them would find their way home to their desired spawning point. Salmon who can't find their home stream will either just go to spawn with other salmon or die trying to find their way home. Remarkably though, the vast majority of salmon that survive to spawning maturing do manage to find home again.
4. Salmon find their way home using both smell and magnetic field
So how do salmon find their way home? Out of the vast oceans and the countless streams, how do these remarkable fish manage to pinpoint the right stream and locate the place where they came from? Scientists have a few thoughts on this subject.
The first is that some salmon determine their home stream through their sense of smell, which may be sharper than that of dogs or other animals with keen senses of smell. Another thought is that salmon "imprint" the magnetic field of the waters where they are born and then use that mental note to find their way home later. Everything from ocean currents to tides reportedly helps with this method.
5. Their diet is what results in their distinctive pink color
Perhaps the most iconic thing about the salmon fish species is their distinct pink color. Many clothing companies even have "salmon" as a color choice in their catalogs, a color word used to describe the delicate, reddish pink hue that has become extremely popular in recent years. However, the famous salmon color is not even something that is dictated in the fish's DNA.
Instead, salmon get their color thanks to their diet. Specifically, the color comes from an anti-oxidant carotenoid called astaxanthin. This chemical is produced in the chloroplasts of yeasts and algae. Salmon don't feed on algae and yeast, but the small baitfish species that make up the majority of their diet do. Astaxanthin therefore accumulates in salmon and turns them a reddish pink color.
6. Female salmon lay eggs into small depressions they make in the riverbed
Upon finally finding her way back to her home waters, a female salmon will use her tail to dig small depressions into the riverbed and lay her eggs there. The female can dig as many depressions as necessary to lay all her eggs. Since a single female salmon can lay anywhere between 1,500 and 10,000 eggs, the number of depressions generally ranges from one to seven.
Once each depression has been dug and the eggs laid, the male parent will fertilize the eggs and the mother will then bury them. Despite the vast number of eggs left in these depressions however, estimates say that fewer than 10 of these eggs have shot at producing salmon that will survive to adulthood.
7. Almost all salmon die immediately after spawning
Most salmon quite literally kill themselves trying to battle their way upstream back to where they were born. Once they spawn, they simply have no more energy left to give. Salmon don't even continue feeding once they leave the ocean and return to freshwater. Instead, many essentially resign themselves to passing on once they have reproduced, closing out their own circle of life.