July 5, 2022

Vertebrata is a subtype of chordate animals distinguished by the presence of a bony spine. Together with insects, this group of animals dominates on land and in water. The rest of the animals are sometimes combined into a non-systematic group of invertebrates. The use of this term is justified only by the important role that vertebrates play in the modern animal world, since otherwise the group of invertebrates unites organisms that often have almost nothing in common. The vertebrate group is often considered the higher chordates. In comparison with lower chordates - lanceolates and integuments, they are characterized by a much higher level of organization, which is clearly expressed both in their structure and physiological characteristics. Among vertebrates, there are no species leading a sedentary (attached) lifestyle. They are constantly moving, actively searching for and capturing food, finding individuals of the opposite sex for reproduction, and escaping from the pursuit of enemies. Active movements provide vertebrates with the opportunity to change the environment depending on changes in the conditions of existence and needs at various stages of their life cycle, for example, during development, puberty, reproduction, hibernation, etc. The indicated general biological features of vertebrates are directly related to the peculiarities of their morphological organization and physiology. The nervous system of vertebrates is much more differentiated than that of lower chordates. All animals of this group have a developed brain, the functioning of which determines higher nervous activity - the basis of adaptive behavior. Vertebrates are characterized by the presence of various and complexly arranged sense organs, which serve as the main link between the living organism and the external environment. The development of the brain and sense organs is connected with the appearance of the skull, which serves as a reliable case for these important organs. As the basis of the skeleton, instead of the chord, in vertebrates there is a more perfect and stronger vertebral column, which performs the role of not only the support rod of the body, but also the case containing the spinal cord. In the region of the front part of the intestinal tube, mobile parts of the skeleton arise, from which the oral apparatus is formed, and in the vast majority, the jaw apparatus, which ensures the capture and retention of food, and in the higher