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

The animal World is diverse and amazing. They differ from each other in many biological characteristics. I want to focus on the relationship of animals to ambient temperature and find out: cold-blooded animals is what?

General concepts

In biology there is the concept of cold blooded (poikilothermic) and warm blooded (homoiotherm) organisms. It is believed that cold-blooded animals are those whose body temperature is not constant and depends on the environment. Warm-blooded animals do not have such dependence and persistent body temperature. So what animals are called cold-blooded?

A Variety of cold-blooded animals

In Zoology, cold-blooded animals – are examples of the lowly classes of the animal world. They include all invertebrates and part of the vertebrates: fish, amphibians, reptiles. With the exception of crocodiles, which are reptiles. Currently, this type also include another mammalian species, the naked mole rat. Studying the evolution, many scientists, until recently, attributed to the cold-blooded and dinosaurs. However, at the present moment there is a perception that they were warm-blooded at the inertial type of thermoregulation. This means that the ancient giants had the ability to accumulate and retain due to the huge mass of the solar heat, which allowed them to maintain a constant temperature.

Characteristics of life

Cold-blooded animals are those who, because of a poorly developed nervous system is an imperfect system of regulation of basic vital processes in the body. Consequently, the metabolism of cold-blooded animals also has a low level. Indeed, it flows much slower than in warm-blooded (20–30 fold). When the body temperature is above 1-2 degrees of ambient temperature or equal to it. This dependence is time-limited, linked to the ability to store heat from objects and the sun to keep warm or as a result of muscular work in case there are supported approximately constant parameters. In the same case, when the external temperature drops below the optimum, all metabolic processes slow down cold-blooded. The animals ' reactions become inhibited, remember sleepy flies, butterflies and bees in the fall. When there is a decrease in temperature for two or more degrees in nature, these organisms fall into a torpor (hibernation), experience stress and sometimes die.

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Seasonality

In inanimate nature there is a concept of changing seasons. Especially pronounced these phenomena in Northern and middle latitudes. Absolutely all organisms respond to these changes. Cold-blooded animals are examples of adaptations of organisms to temperature changes in the environment.

Adaptation to the environment

Peak activity cold-blooded and basic life processes (mating, reproduction, breeding progeny) falls during the warm period of spring and summer. At this time, everywhere we can see many insects and observe their life cycles. In riparian and aquatic areas you can find a lot of amphibians (frogs) and fish at different stages of development.

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

With the arrival of autumn or in late summer, animals start to prepare for the hard winter that most of them are in suspended animation. In order not to die during the cold weather, the preparatory processes for the supply of nutrients in their bodies happen in advance during the summer. At this time cellular structure changes, it becomes less water and more dissolved components that will ensure the process of feeding all winter. With decreasing temperature the level of metabolism also slows down, the power consumption is reduced, which allows cold-blooded all spend the winter in hibernation, not caring about getting food. Also important stage of preparation to adverse temperature conditions is the construction of a closed "room" for the winter (holes, burrows, houses, etc.). All of these life events are cyclical and are repeated from year to year.

These processes are also the unconditioned (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 to be pisnespivy.

The Impetus for the awakening from suspended animation is the increased air temperature to the required level, which is characteristic for each class, and sometimes kind.

According to evolutionary theory, cold-blooded animals are inferior beings, which is due to the weak development of the nervous system mechanisms of thermoregulation is also not perfect.