Introduction to zoology: cold-blooded animals - who is this?

The world of animals is diverse and amazing. They differ from each other in many biological characteristics. I want to dwell on the attitude of animals to the temperature of the environment and to find out: cold-blooded animals are what?

General concepts

In biology, there are concepts of cold-blooded (poikilothermal) and warm-blooded (homoiothermal) organisms. It is believed that cold-blooded animals are those whose body temperature is unstable and depends on the environment. Warm-blooded animals do not have such a dependence and differ in the constancy of body temperature. So what animals are called cold-blooded?

A variety of cold-blooded animals

In zoology, cold-blooded animals are examples of low-organized classes of the animal world. These include all invertebrates and part of vertebrates: fish, amphibians, reptiles. The exception is crocodiles, which are also reptiles. Currently, this type also includes another species of mammals - a naked excavator. Studying the evolution, many scientists until recently attributed to the cold-blooded and dinosaurs. However, at the present moment there is an opinion that they were still warm-blooded by the inertial type of thermoregulation. This means that the ancient giants had the ability to accumulate and retain at the expense of a huge mass of solar heat, which allowed them to maintain a constant temperature.

Features of life activity

Cold-blooded animals are those that, due to a weakly developed nervous system, have an imperfect system of regulation of the vital vital processes in the body. Consequently, the metabolism of cold-blooded animals also has a low level. Indeed, it proceeds much more slowly than warm-blooded animals (20-30 times). At the same time, the body temperature is higher by 1-2 degrees of ambient temperature or equal to it. This dependence is time-limited and is related to the ability to accumulate heat from objects and the sun or to be warmed as a result of muscular work in the event that approximately constant parameters are maintained outside. In the same case, when the external temperature drops below the optimum, all metabolic processes in the cold-blooded are slowed down. The reactions of animals become inhibited, remember the sleepy flies, butterflies and bees in the fall. When there is a decrease in the temperature regime by two or more degrees in nature, these organisms fall into a stupor (anabiosis), experience stress, and sometimes die.

Seasonality

In inanimate nature, there is the notion of changing the time of the year. These phenomena are especially pronounced in the northern and temperate latitudes. Absolutely all organisms react to these changes. Cold-blooded animals are examples of adaptations of living organisms to temperature changes in the environment.

Adaptation to the environment

The peak of activity of the cold-blooded and the basic life processes (mating, reproduction, breeding of offspring) falls on a warm period - spring and summer. At this time, we can everywhere see a lot of insects and watch their life cycles. In the water and water areas, you can find a lot of amphibians (frogs) and fish at different stages of development.

In the forests and meadows, reptiles (lizards, snakes, snakes) of different generations are quite common.

With the advent of autumn or at the end of summer, animals begin to intensively prepare for wintering, which most of them spend in anabiosis. In order not to die in the cold season, preparatory processes for the supply of nutrients in their organisms occur in advance, throughout the summer. At this time, the cellular composition changes, it becomes less water and more dissolved components, which will ensure the process of nutrition throughout the winter period. With a decrease in temperature, the level of metabolism also slows down, the energy expenditure decreases, which allows the cold-blooded to spend the whole winter in hibernation, not caring about food production. Also an important stage in preparing for unfavorable temperature conditions is the construction of closed "rooms" for wintering (pits, burrows, houses, etc.). All these life phenomena are cyclical and repeat from year to year.

These processes are also unconditional (innate) reflexes, inherited from generation to generation. Animals that undergo certain mutations in the genes responsible for the transmission of this information die within the first year of life, and their offspring can also inherit these disorders and be unviable.

The impetus to awakening from anabiosis is the rise in air temperature to the required level, which is typical for each class, and sometimes the species.

According to the evolutionary theory, cold-blooded animals are lower creatures, because of the weak development of the nervous system, the mechanisms of thermoregulation are also not perfect.