Who knows how freshwater fish evolved, evolved from marine fish, or if they existed inherently

How freshwater fish evolved is not particularly clear, but it is certain that they neither evolved nor were they inherently existent. Some studies suggest that freshwater fish may have been formed by the Paleozoic marine fish after a mass extinction event in Earth's history over a long period of time and adaptation to the environment. These fish begin to live in freshwater rivers and lakes, and then gradually adapt to different water environments and develop a variety of morphological and ecological roles.

The evolution of freshwater fish may include many different environmental and ecological factors, such as the physicochemical characteristics of the waters, food**, competitive pressures, and reproductive behavior. Together, these factors affect the morphology, physiological characteristics and behavioral habits of freshwater fish, making them gradually adapt to the freshwater environment.

It should be noted that there are still many unsolved mysteries about the evolution of freshwater fish, which require further research and exploration.

Evolved from insects, a new study shows that most of the planet's current marine fish may have evolved from freshwater fish, tracing the genealogy of marine and freshwater fish. The findings of this study could help explain why the oceans have relatively low biodiversity compared to land. Oceans occupy up to 70% of the Earth's surface, but contain only 15%-25% of the Earth's species.

The first fish were jawless, and as the name suggests, they were fish that did not have upper and lower jaws. Unable to hunt by opening and closing their mouths, they suck water containing tiny animals and sediment into their mouths, and one of them is covered with hard bone fragments called "armor" and lives on the ocean floor. They first appeared in the Early Cambrian period more than 500 million years ago and were the first fish to differentiate.

The main representatives of jawless in the oceans at that time were armored fishes.

Later, due to genetic mutations, the first fish with jaws appeared, and jawed fish were able to hunt actively and effectively. Under the natural selection of "natural selection, survival of the fittest", more and more jawed fish began to appear, and jawless fish fell into disadvantage in hunting competition.

In order to survive, some fish have evolved super-strong jaws that can split sharks in two, while others have begun to explore new horizons.

The emergence of jawed fish has made the competition for survival in the ocean more and more fierce, and the food chain of "big fish eat small fish, small fish eat shrimp" has been formed since then.

Did human life evolve from fish?

Scientists have found that humans actually evolved from fish? Here's how the evolution went.

The research given in biology only tells the process of human evolution from fish, but there is no way to explain what happened to fish before, how various organisms on the earth came into being, and humans cannot answer this question.

I think so, because fish existed much earlier than terrestrial organisms.

No, there are all sorts of speculations about the evolution of humans, and there is no scientific basis to prove that humans evolved from fish.

Not sure, it depends! There are some offshore dammed lakes, tectonic lakes, artificial lakes, etc., which have been separated from the sea very recently, and the fish in them have the opportunity to come from the ocean and have no reproductive isolation.

If it is a saltwater lake that is deep inland, formed by tectonic or volcanic processes, then it has nothing to do with the sea, and the fish in it must have evolved independently.

But for example, the Aral Sea, the Caspian Sea, etc., these lakes are sea trace lakes, that is, they were part of the ocean in ancient times, and then the earth's crust rose and separated from the sea. The fish in these lakes come from both the ocean and the freshwater fish of rivers (and over the years, even the fish that originally came from the ocean have been reproductively isolated from most of their relatives in the sea). ）

The fish in the saltwater lake are directly from the ocean or.

Fish bones are elongated, elastic bones in the muscles of the fish's body to increase the strength and strength of the connections between the muscle bundles. It allows the fish's muscles to reflex faster and have more strength.

Whether it is freshwater fish or marine fish, vegetarian fish have more bones and less carnivorous fish bones. Because, if a vegetarian fish wants to escape the predation of predators, it must react quickly and act quickly, so that it has a chance to escape and have the possibility of reproduction. The unresponsive and clumsy can only be eaten by others.

Natural selection, the surviving species can only escape from the predator's hunt by adapting to the environment. Among fish, it is a vegetarian with many spines.

In general, the ocean has much more room to move than freshwater. There is also a large space for marine fish to find food and escape. So as a vegetarian fish, marine fish will have fewer spines than freshwater fish.

On top of that, most of the marine fish we eat are carnivorous, and most of the freshwater fish we eat are vegetarian. So most people would come to the conclusion that marine fish have fewer bones than freshwater fish.

Fish is one of the main meats of humans**. In terms of broad classification, fish can be divided into freshwater fish and marine fish. In our daily life, many friends must have the same cognition as the subject, that is, freshwater fish have more spines than marine fish, especially the small spines on the fish, which makes people want to eat fish and dare not eat it.

So, do freshwater fish really have more bones than marine fish? The answer is no, it depends on what kind of fish it is. Some freshwater fish have fewer spines than marine fish, while some marine fish have more spines than most freshwater fish. Below, we will discuss this issue in detail.

Fishes are the largest vertebrates, accounting for the entire vertebrate. Freshwater fish and marine fish are the two major components of fish, where freshwater fish refers to water with a salt content of less than 3, while fish living in water with a salt content of more than 3 are called marine fish.

Freshwater fish are the main fish we eat (except in coastal areas), and the common ones are carp, crucian carp, grass carp, silver carp, etc. These fish have a lot of "small spines" on their bodies. In fact, the scientific name for these small spines is "interscalene bone spurs" (hereinafter referred to as bone spurs).

But not all freshwater fish have many bone spurs, such as blackfish, sea bass, Wuchang fish, mandarin fish, etc. These fish are relatively common freshwater fish, but these fish have only one main bone spur in their body and no or very little extra bone spurs.

The ichthyological explanation is that intermyenteric bone is a fine spiny bone formed by the ossification of connective tissue in the muscle septum, which is more common in lower bony fish (bony fish), and usually higher fish do not have intermuscular bone.

Common freshwater fish, such as herring, grass carp, silver carp, bighead carp, bighead carp, carp, etc., all belong to the carp-shaped head, which is a relatively low-level bony fish in evolution.

Common marine fish, such as sea bass, grouper, mandarin fish, large yellow croaker, etc., belong to the perch-shaped head, which belongs to the higher class of bony fish, usually with fewer spines.

People will also be divided into men and women, black and white, not to mention fish, which is closely related to the living environment, freshwater fish are more suitable for freshwater, and saltwater fish are adapted to the minerals contained in seawater.

Because the salt content in the sea is very high, some fish can adapt to it, and the salt in the fresh water is relatively small, so there is such a difference.