Freshwater Fish: Living in Rivers and Lakes

Freshwater fish are fish that spends a few or the greater part of their lives in freshwater, for example, such as rivers and lakes. It is estimated that more than 500 million years ago that fish are in the waters of this planet. And that the conquest of freshwater began about 417 million years ago.

Since then, when the first explorers began to roam the mouths of the rivers. The fish have had to adapt their organs, kidneys, respiratory apparatus and their complete organism to the freshwaters.

Freshwater Fish

Characteristics of Freshwater Fish

Freshwater fish live in rivers, lakes, etc. In these habitats, the salinity of the water is reduced. In their physiology what characterizes them is that their organism concentrates a greater degree of salinity than the environment that surrounds them. Thus, their gills absorb the salts and their kidneys expel the water through the urine.

Some examples of more well-known freshwater fish are the barbel, the carp, the perc, the trench and the trout. In the case of aquarium freshwater fish, we can find cichlids, catfish, etc. Freshwater fish contain potassium, magnesium, and phosphorus. You May Also Like To Read Saltwater Fish.


It is a very abundant fish in the marshes and in the rivers of calm waters. It is not a fish much appreciated since its flavor is something muddy and also has many thorns. In a way, you can look like the muil, since your eating habits are a scavenger. To disguise this flavor, if it is included in our diet, we must macerate it or marinate it to soften its flavor.


It is a very voracious, resistant fish and is considered one of the most harmful species of fish in the world due to its invasive nature. Its origin comes from Asia and was introduced into the waters of the whole world except Antarctica. It has great scales and its main attraction is sports fishing.

It is only appreciated in oriental cuisine, especially in China and Japan and is a typical Christmas dish in some Eastern European villages. Its consumption is very versatile, admitting preparations from the frying to the preparation in the oven. In Spain, it is not appreciated this species, but it is of interest for sports fishing. As a curiosity, I commented that what we traditionally know as “goldfish” (red, yellow and mostly maroon). This is a variety of carp cultivated by the Chinese and Japanese.


Perch is an abundant fish throughout Europe. This species has hard and rough scales and presents a greenish coloration in the back. And silver in the central zone, with dark stripes on the side. This species is found in the markets, where we can find it in the fish market cut with clean loins, with a soft taste and very fine meat.

It accepts all kinds of preparations and is a white fish. A few years ago this species came to sell as “grouper fillets” when it was really the perch of the Nile River and came to import from Tanzania already made. Sports fishermen usually know it by the name of “black-bass” or perch Americana.


This fish is very fond of living in calm waters, and in ponds, with abundant vegetation used to hide from its predators. Its appearance presents a coloration of greenish to brown depending on the medium in which it develops. We could say that its appearance would look like the Pollack. Especially in the type of small scales and their coloration.

Native River Trout

The river trout is a very clever animal, capable of jumping over a network that can cross from side to side in the channel of the river. Trout is the most important freshwater fish, both from the commercial point of view and from the culinary point of view.

Its presence in the markets, in fresh condition, is daily since all it comes from fish farms. River trout, a real delicacy in gastronomy, its commercialization is not in force. Fishing for this species should be performed at sports and private level is the only case in which allows to consume this species.


The Freshwater fish diet consists of flakes, granules, live foods such as water fleas, which are small crustaceans that are available all year round. Like live foods in nature, such as woodlice because of large fish like them. And there can be nothing better to feed tropical fish than earthworms in the gardens. Another member of this category is the larvae of flies. These foods should last about a week in a cool place.

These foods can only give the fish for a week as they will be fresh. River shrimp should also be supply in this way. Similarly, there are foods with a lot of meat, the heart of reddish meat is good for carnivorous fish. Many fish like to have some vegetables in their diet, including lettuce, peas, and even beans.


The freshwater fish is used to eat as food, and to have in exhibitions such as aquariums and fish tanks.

Special Feature

Unlike in many countries in Europe, in Spain, freshwater fish do not have great esteem for the cuisine of that country. Even in the periods of Lenten abstinence and fasting, the inhabitants of the interior regions, who did not have easy access to the coast, used to prefer sea fish. Freshwater fish could be considered too bland and, to many, taste mud. The exception was the salmon, which came to the river in full development, full of flavors acquired during its sea voyage, and white water trout, which had the meat of the flesh.


This guide has been a deep dive into freshwater fish, from what makes them different to how they are harvested. Hopefully, it’s helped you understand the difference between fresh and saltwater fishing, as well as give you some insight on where to find your next meal. Now go grab that rod and reel! Good luck with catching those elusive trout!

As A References: Wikipedia

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