Frogs are beings who meet practically in each country of the world. They are amphibians, are capable to live both in water, and on the land. Ancient Egyptians considered that frogs have ability to revival, they were a symbol of eternal life. Japanese consider that these unusual beings attract good luck, success and financial prosperity. Therefore it is recommended to keep figurines in the form of toads in houses.
Frogs begin the course of life in water. At first from berries tadpoles hatch. Then they pass up to 30 stages of development before being transformed to an adult individual.
Frogs are carried to a class of amphibians for the reason that these beings are capable to breathe both lungs, and gills. When adult tailless animals are in the water environment, they breathe by means of all body, oxygen arrives through skin. Being still tadpoles, process of breath is carried out by heats. Being on the land, frogs make breaths through a mouth, filling with air lungs.
Wonderfully heart works for these animals. When frogs are under water, they involved 2 departments of heart. The beings who got out to the land have active the left auricle because of what on a body not mixed blood begins to flow. The stream of pure arterial blood arrives to a brain of a frog only on the land.
The food allowance of tailless animals can be very different. Depends on a look, on the habitat. As a rule, frogs eat small insects, for example, of mosquitoes, flies, bees and wasps. However there are also such representatives who willingly regale on whitebaits of fishes. Interesting fact: the frog treats feeling of hunger rather calmly. She is capable to live without food of 7-10 days.
The stomach of any frog is much less, than her eyes. At a mouth these beings have teeth which are only on the upper jaw. They are not intended for chewing of food. Teeth at frogs – a barrier in order that the caught insect did not break loose. Only toads who also treat group of frogs have no teeth.
In the course of ingestion of food a part is played by eyes. If to pay attention, then it is possible to notice that the frog surely blinks as soon as something food gets into her mouth. The fact is that during blinking the eyeballs fall and help to push food in a stomach.
There are some more interesting facts about organs of vision of these tailless animals:
- eyes at a frog are arranged so that the being can look at the same time directly before itself, down, and also control a situation around;
- these animals do not feel the need for continuous blinking;
- even during sleep the frog does not close an eye to long time.
Among representatives of tailless beings there are those which in a size do not exceed 1.5 centimeters. The least frogs in the world are the amphibians living in the territory of Cuba. And Goliath is considered the most huge frog. Length of her body reaches 90 centimeters. Weight can be 2-3 kilograms. Lyagushki-goliafy are able to jump on height in 3 meters, they have very powerful hinder legs.
The surface of a body of these amphibians is covered with usually special slime. It has the disinfecting effect therefore in the past our ancestors threw frogs in milk jars with milk that the product did not deteriorate. Toads at whom slime on a body has hallucinogenic properties live in South America. In the nature there are also frogs at whom the glossy, sticky covering of their body is deadly to animals, people. The koko living in the jungle and toads - aha which weight can reach 2 kilograms are among the most poisonous frogs.