The animal world is diverse and amazing. They differ from each other in many biological characteristics. I would like to dwell on the attitude of animals to the ambient temperature and find out: what are cold-blooded animals?
General concepts
In biology, there are concepts of cold-blooded (poikilothermic) and warm-blooded (homeothermic) 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 this dependence and are distinguished by the constancy of body temperature. So which animals are called cold-blooded?
Diversity 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 - the naked mole rat. By studying evolution, manyScientists until recently attributed to the cold-blooded and dinosaurs. However, at the present moment there is an opinion that they were still warm-blooded according to the inertial type of thermoregulation. This means that the ancient giants had the ability to accumulate and retain solar heat due to their huge mass, which allowed them to maintain a constant temperature.
Features of life activity
Cold-blooded animals are those that, due to a poorly developed nervous system, have an imperfect system of regulation of the main vital processes in the body. Consequently, the metabolism of cold-blooded animals also has a low level. Indeed, it proceeds much more slowly than in warm-blooded animals (20–30 times). In this case, the body temperature is 1-2 degrees higher than the ambient temperature or equal to it. This dependence is limited in time and is associated with the ability to accumulate heat from objects and the sun, or to warm up as a result of muscular work, if approximately constant parameters are maintained outside. In the same case, when the external temperature drops below the optimum, all metabolic processes in cold-blooded animals slow down. Animal reactions become inhibited, remember sleepy flies, butterflies and bees in autumn. When the temperature regime drops by two or more degrees in nature, these organisms fall into a stupor (suspended animation), experience stress, and sometimes die.
Seasonality
In inanimate nature there is a concept of change of timeof the year. These phenomena are especially pronounced in northern and temperate latitudes. Absolutely all organisms respond 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 cold-blooded animals and the main life processes (mating, reproduction, breeding) falls on the warm period - spring and summer. At this time, we can see many insects everywhere and observe their life cycles. In near-water and water areas, you can find a lot of amphibians (frogs) and fish at different stages of development.
Reptiles (lizards, snakes, snakes) of different generations are quite common in forests and meadows.
With the advent of autumn or at the end of summer, animals begin to intensively prepare for wintering, which most of them spend in suspended animation. In order not to die during the period of cold weather, preparatory processes for the supply of nutrients in their bodies occur in advance, throughout the summer. At this time, the cellular composition changes, it becomes less water and more dissolved components that will provide the nutrition process for the entire winter period. With a decrease in temperature, the level of metabolism also slows down, energy consumption decreases, which allows cold-blooded animals to hibernate all winter, not caring about food production. Also an important step in preparing for adverse 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 unconditioned (congenital) reflexes that are inherited from generation to generation. Animals that undergo certain mutations in the genes responsible for transmitting this information die within the first year of life, and their offspring may also inherit these disorders and be unviable.
The impetus for awakening from hibernation is an increase in air temperature to the required level, which is characteristic of each class, and sometimes species.
According to evolutionary doctrine, cold-blooded animals are lower creatures, in which, due to the weak development of the nervous system, thermoregulation mechanisms are also not perfect.
