Freshwater fish are animals that are in the group of vertebrates, which live in the depths of rivers, lakes, and other freshwater channels around the world, are able to withstand large changes in temperature due to anatomy. from her body.
Characteristics of freshwater fish.
As we have mentioned before, the freshwater fish are living beings that develop mainly in rivers, lakes, and lagoons; This type of habitat where it develops is small but enough so that they can survive comfortably.
They contain special gills that help them regulate their temperature in the water, their body is usually covered by scales that regulate the low temperatures; in its anatomy you can also see some scales throughout your body that allows them to have a better mobility.
observe the various freshwater fish there are in the world
Its evolution is a subject that is still under discussion by many experts, since there is not yet an exact time in which to demonstrate the beginnings of the freshwater fish, since those beginnings the structure of these fish was gradually changing. which by different investigations and studies have shown that its anatomy has been altered by the passing of the years, today there are smaller and more varied species depending on the families to which they belong.
In the case of freshwater fish if anatomy depends on the water where they are developing; since not all the waters are equal, some are denser than others, so each type of fish adapts little by little.
They have the same body appearance as most vertebrates, their characteristics may vary depending on the species to which they belong, their body is composed of head, trunk or abdominal area and tail.
In the head contains gill zones which allows them to store the greatest amount of oxygen and to be able to breathe properly in the water, in its trunk or abdomen are most of the organs of the same, where you can also see a pair of fins which They give you the greatest possible mobility in the water.
The tail represents another extra complement of its anatomy, since the same one in company of the dorsal fins in the trunk area are those that give all the movement to the freshwater fish, allowing them to reach the necessary speed to move along and width of the waters where they live.
Their skin, like other vertebrates, contains special characteristics, most freshwater fish are covered by scales, which allow them to resist the different temperature changes at which they are continuously exposed, although not all of them the species have scales in their body some species of freshwater fish contain another type of structure very similar to the scales that fulfill the same function.
The feeding of freshwater fish only depends on what is found in their habitat and the nutrients they provide for them; and for that reason it causes the feeding habits of the fish to be very diverse and may vary according to the case.
Feeding can also vary according to the type of freshwater fish that is being treated, since there are a diversity of families that feed on different types of food in the water, whether they are carnivores, herbivores, or other categories.
Freshwater carnivorous fish.
This type of species of freshwater fish feeds specifically on smaller fish, but at the same time they can consume any type of species that inhabit the water, such as insects and molluscs, although the latter is not very common among them and only consume when they see the need to do so.
There are several types of fish that develop certain characteristics that allow them to eat their food completely, many are considered carnivorous fish just by eating insects that live in the waters, the peculiarity of which is that only in fresh water they consume insects and are part of them of this category.
Herviborous freshwater fish.
This type of food is more common in freshwater fish, since the most abundant in this type of water are algae and plants which provide a large amount of nutrients they need to survive; although it abounds this type of food for these fish, they are the most difficult to digest for them, since their content is so heavy that they cause the digestive system to remain in operation all day.
The studies carried out on this type of species have reached the conclusion that the majority of freshwater fish that consume this type of food usually complement their diet with some living species, that is, they can also become carnivores, with the sole purpose of improving your digestion get better mobility in the water.
Omnivorous freshwater fish.
This category represents the diet of most freshwater fish, since they seek to supplement their diet with both plants and living beings, even though these fish do not eat the same foods that carnivorous fish eat. they prefer to feed on other types of species and not on other fish.
The best example of omnivorous freshwater fish are the piranhas, which despite the fact that the world knows them as one of the most ruthless carnivorous species, since they also often supplement their diet with various plants found in freshwater of the Amazons where they develop.
Freshwater filter fish.
This type of species is not particular, but many species of freshwater fish have been known to practice this type of filtering techniques for their feeding. The filtering process is nothing more than the intake of large amounts of water, where the same fish try to filter only the nutrients that it carries, since in it there are several microorganisms that allow them to feed on them.
Freshwater detritivore fish.
We can not forget this type of category because there are many freshwater fish that feed in this way, being a detritivore fish is nothing more than consuming the waste that other fish usually leave, this mostly occurs in the species that are in captivity stored in aquariums, which manage to survive using this type of techniques for feeding.
The reproduction of the fish does not vary whether it is freshwater or saltwater fish. Its reproduction is the same, it occurs in certain periods of time, which can happen every month or every year, depending on the species and the external factors. those that develop like the temperature and feeding.
The freshwater fish has its sexuality well marked, there are males and females, but it may be the case that some species where sex can change suddenly, but this does not happen in the case of freshwater fish.
The distinction of sex between fish is not easy since it is not at first sight their reproductive apparatus to be able to reach the conclusion of whether it is male or female, the only way that has been found and thanks to different studies is that males and females They can be differentiated by the coloration of their skin or by the anatomy of the species as the case may be.
This type of reproduction in freshwater fish is generated when the female proceeds to expel the eggs in the middle of the water, this is considered that the fecundation of the same occurs externally, although there are many oviparous species that prefer to create species of nests to protect their eggs, these are created mostly by the male which stores them in a kind of bubble until the egg fecundates and is born.
In this type of reproduction of freshwater fish occurs with the combination of various unusual characteristics among other species, this type of reproduction occurs internally between males and females, causing the fertilization of eggs is made in your womb but at birth the same are already formed species.
The peculiarity of this type of fecundation is that females can get pregnant several times without the need for the male to penetrate them, since after the first reproduction they store a certain amount of sperm to serve them in other fecundations after the first one.
Distribution and habitat.
The majority of freshwater fish are found among rivers and lakes around the world, this is due to their distribution but if we refer to their habitat this is a slightly more limited characteristic as over the years and the hand of man intervening in different points for the exploitation of certain natural riches, have mostly harmed the natural habitat of freshwater fish.
Mostly you can find freshwater fish diversity in the different rivers of North America and South America, being the same the most appropriate waters to house the different species but due to the invasion of man to the habitat of the same many conservative foundations of them they have seen the need to move them to much colder areas such as northern Asia and Europe respectively.