Fish ecology is a section of ichthyology that specializes in the study of the lifestyle of fish:
Pisces are a class of vertebrates that live only in reservoirs, although there are bicomsucking fish that can stay on land for some time (protopopters, anabasy, and slate jumps). They spread throughout the corners of the earth, from hot tropical to cold Arctic latitudes. In oceans and seas, fish can live at a depth of more than 1000 meters, so there are species that are still unknown to modern science. It is also possible from time to time to open prehistoric species that existed 100 million. years ago, or even ancient. More than 32.8 thousand are known in the world. species of fish, the dimensions of which vary from 7.9 mm to 20 m.
Scientists distinguish such groups of fish, depending on the features of their habitat:
The influence of hydrosphere factors on the lifestyle of fish
One of the most important factors that provide life for fish is light. Good lighting allows them to navigate well in water. The deeper the fish live, the less light goes there, and the species that live very deeply either at the bottom or blind, or perceive the weak light with telescopic eyes.
Since the body temperature of fish depends on the temperature of their environment, therefore, warm and cold water affect their life cycles differently. In warm water, fish activity, their growth, feeding, reproduction and migration are observed. Some fish are so adapted to the heat that they live in hot springs, while others are able to withstand the low degrees of the waters of Antarctica and the Arctic.
Fish get oxygen from the water, and if its condition worsens, it can lead to slow development, disease, and even death of entire populations. So dangerous for fish various pollution of the hydrosphere, especially oil spills. According to the way of feeding, fish are predatory, peaceful and omnivorous. They have relationships between individuals of the same and different species, as well as with representatives of other classes of fauna.
Thus, fish are the most valuable aquatic animals that inhabit reservoirs of all types, live not only in rivers, lakes, oceans, seas, but also in captivity in aquariums. They have significant differences from each other, and modern science has yet to learn a lot about them.