Crayfish are found in freshwater bodies. They can be found both in full-flowing rivers, and in small streams and even lakes, where the depth reaches three or more meters. At the same time, crayfish are very demanding on the purity of water. It is for this reason that their number is rapidly declining, there are less and less clean reservoirs.
The basis of crayfish nutrition is in plant food. They eagerly eat algae, aquatic plants and leaves that have fallen into the water. At the same time, crayfish do not refuse animal food: worms, insects, larvae, dead fish can become their victims. Especially the one that starts to decompose. can catch this smell at a great distance and leave its shelter even during the day, despite the fact that crayfish prefer to conduct night hunting.
The coloring of the body largely depends on the environment in which it lives. Depending on the color of the bottom, it can have a color from black to gray-green. It is generally accepted that crayfish are slow, but, in case of danger, they are able to develop a fairly decent speed.
The body length can reach upto 25 centimeters. But, not all crayfish reach such gigantic sizes: the usual length is 10-15 centimeters. At the same time, males are usually larger than females. The size of the newborn crayfish is about 2 mm. Life expectancy is up to 20 years. Some "centenarians" are able to live a quarter century.
Females carry eggs under the abdomen. The usual norm is 200-300 eggs. But, of these, only a small part will reach adulthood. And most will be the victims of predatory fish. After the birth of small crustaceans, they are next to their mother for about two weeks, after which they begin an independent life.
In adults, molting occurs once or twice a year. the timing largely depends on the habitat. During molting, the old chitinous cover disappears, in its place a new one gradually grows. At this time, the crayfish become absolutely defenseless, therefore, they prefer to wait out the burrowing process of shelling.
The tail plays a huge role in the life of crayfish. If for some reason he lost his claw, then after a while he will grow a new one. But the tail can no longer recover. Without a tail, the crayfish is unable to move and crawl out of the water onto land. And he needs to do this periodically in order to replenish the oxygen metabolism in the body.
For a long time, our ancestors used crayfish not as a delicacy for beer, but used them for medicinal purposes. For example, ancient doctors were sure that if the ashes of a burnt crayfish were sprinkled with a rabid animal or a poisonous snake, the poison would be neutralized.
crayfish were considered an excellent anti-alcohol remedy. The crayfish had to be ground into powder and sprinkled with alcohol. It was believed that such an additive causes severe vomiting, and a person has a steady aversion to alcohol.
Different peoples of the world had an ambiguous attitude towards the consumption of crayfish for food. Some considered crayfish to be a delicacy, others considered “dirty food”. For example, in Sweden in the 16th century, peasants were obliged to catch crayfish and deliver them to the royal table. At the same time, the peasants themselves were strictly forbidden to eat “royal” food.
In modern Sweden, laws are more democratic; everyone is allowed to eat crayfish. In August, even the festival of "eating crayfish." Until 1994, it was forbidden to catch crayfish in the country. So gourmets attacked their favorite crayfish dishes in the last month of summer. The ban was lured 25 years ago. However, few Swedes catch crayfish in the rivers; they are bought in huge quantities in China and Turkey.
As you know, crayfish turns reddish during cooking. This is due to the fact that the shell contains astaxanthin, a substance from the group of carotenoids. In boiling water,
And, of course, the most important question is - where are the crayfish wintering? Biologists claim that there are no special secrets in their wintering: crayfish try to lie deeper in the bottom, where the water is warmer. They do not fall into hibernation for the winter, but they spend most of their time in "half-asleep", only hunting for a few hours.
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