River crayfish appeared quite a long time ago, more than 100 million years ago. They live in almost all fresh water bodies, so the name of this class is not entirely justified. Crayfish settle in rivers, lakes, as well as in any bodies of water and depressions with a depth of 15 meters. It would be more expedient to call them not river crayfish, but freshwater crayfish.
Description and habitat
Crayfish live in clean running water – rivers, lakes, streams with a small current. Often in the daytime they hide under rocks, tree roots, or in small burrows at the bottom of water bodies. At night, they crawl out to hunt. Cancers are omnivorous. Both plants and fauna can serve as food for them. Moreover, they eat both live and dead prey. River crayfish, unlike other representatives of predatory animals, do not kill their prey, but hold tightly with their claws and bite off small pieces from it.
The crustaceans of the fauna live in reservoirs with a hard muddy bottom, at a depth of up to 3 meters.
The crayfish is dressed in a hard chitinous carapace that covers its soft parts of the body. It has a greenish-brown color, which remarkably protects it from hazards at the bottom of the reservoir, making it invisible. The body of the cancer consists of two parts: the cephalothorax and the abdomen. The arthropod abdomen consists of 5 pairs of limbs that allow the cancer to swim. And the sixth and seventh pairs form the caudal fin. The organs of touch and smell in crayfish are mobile antennae located in the head region. Several pairs of limbs extend from the chest: the first three pairs are used to grab food, then claws follow and the remaining 4 pairs are used for movement. The gills of the crayfish are located in the gill chambers, covered from the internal organs by the integuments of the body, and from the environment by a strong chitinous shield.
Composition and nutritional value
Cancer meat is a very healthy and nutritious product. It contains a large amount of protein – about 16 g, and at the same time has an absolutely low amount of fat – only 0,95 g. This product is easily absorbed by the body and has a rather low calorie content – only 76 kcal. Thanks to this, crayfish is a food in demand in the dietary field. Also, crustaceans contain quite a lot of water in their composition – 82,24 g, slightly more than 1% carbohydrates, a considerable amount of organic acids and various minerals. Cancer meat is enriched with calcium, magnesium, chromium, phosphorus, potassium, sulfur, cobalt and fluorine. It is dominated by B vitamins, as well as vitamins C and E, due to which cancers have antioxidant and regenerating properties and strengthen the body after illness. Cancer contains a large dose of iodine, so it is recommended to take it to prevent thyroid problems. But there is no harmful cholesterol in crustacean meat.
Useful Properties
Crayfish meat has long been eaten. Most of all it is contained in the belly of the crayfish and very little in the tentacles. They are boiled, salted, lightly crushed with parsley or dill and served. In the process of heat treatment, crayfish acquire a rich red color, thanks to the numerous carotenoids included in their composition. It was from here that the phraseological unit “Red as a cancer” came from. After all, crayfish are initially of a completely different color, and at the time of cooking they suddenly turn red.
Crayfish are renowned for their excellent taste. Their meat is very nutritious due to the fact that it contains a large amount of protein. Crayfish are rich in calcium, which has a beneficial effect on the condition of the skin, hair and nails, and iodine, which is necessary for the prevention of thyroid diseases. It is recommended to use them for those who have problems with the cardiovascular system and liver. This product contains a very low amount of fat, while having a low calorie content – this is just a godsend for those who want to lose weight. Crayfish meat speeds up metabolism and fills the body with vigor and energy. And the chitinous shell is successful in folk medicine due to its antiseptic properties. It has also been proven to have the ability to heal wounds.
Hazardous properties
Cancer meat is a rather allergenic product, and therefore it is recommended to use it with great care, especially for people prone to allergies. Also, you should not abuse crustaceans for people with thyroid problems. Although, it would seem, cancer is so rich in iodine that it should, on the contrary, have a positive effect on the course of the disease. But doctors especially emphasize the fact that iodine-rich cancer meat can only be used to prevent the problem. It is not used to treat disease.
Incorrectly prepared cancer can become a source of gastrointestinal problems and dangerous poisoning. It must be remembered that an exceptionally fresh product is suitable for cooking in order to avoid undesirable consequences. It is necessary to observe not only the correct cooking process, but also the storage of crayfish meat. It is better to store the product in a glass container, since the sulfur in its composition does not allow the use of metal products for this. Upon contact with it, the crustacean meat turns black and quickly deteriorates.
Medical use of cancer
River cancer is widely used as a restorative and rehabilitative agent in modern and folk medicine. Due to the fact that its shell consists of chitin, a rich source of chitosan, it has the ability to remove radionuclides and heavy metals from the human body. Therefore, preparations from chitinous plates of crustaceans are successfully used in people who have been exposed to radioactive irradiation, or who work in places where the level of radiation exceeds the established norms.
Also, the shells of crustaceans are often used for medical purposes for the manufacture of artificial skin, for the production of drugs that promote wound healing and high-quality treatment of scars, as well as suture material. Treatment with drugs containing chitinous plates of the shell of crustaceans is recommended, and for those who have undergone an operation of an oncological nature or underwent a course of chemotherapy. The thing is that they contain precious calcium, which accelerates the regeneration processes of the affected organs and tissues and contributes to the successful rehabilitation of patients. In addition, chitosan helps to strengthen joints and is used to prevent arthritis and arthrosis.
As mentioned above, crustacean meat is characterized by a high iodine content. Besides the fact that eating crayfish in food will relieve thyroid problems, it will also have a positive effect on the growing body. After all, iodine is very important for children and adults, and is also necessary for pregnant women.
It should be used with caution during pregnancy and lactation, as well as in the children’s diet, as there is a risk of developing allergies.
It is also recommended to eat crayfish meat when:
- cardiovascular insufficiency;
- kidney problems;
- diseases of the pancreas;
- diseases of the liver and biliary tract;
- digestive problems.
Use in cosmetology
In the field of cosmetology, crayfish are famous precisely because of the substance contained in the chitinous plates of their shell – chitosan. Preparations based on it have a beneficial effect on the skin: they protect from ultraviolet radiation, from the negative effects of the environment. The fact is that chitosan, when applied, forms a thin, invisible protective film on the skin surface, which significantly reduces the process of evaporation of liquid from the skin. In this connection, the skin remains hydrated for a long time and is less susceptible to free radicals.
Cosmetic products with elements of crustacean chitinous cover are very valuable, as they consist of natural, environmentally friendly ingredients. Chitosan is easily absorbed by the cells of the body and absolutely does not have a bad effect even on sensitive skin. And since this component also carries a regenerating property, it is very often used in the production of anti-aging cosmetics aimed at rejuvenating and restoring the structure of the skin. Preparations with chitosan are used in the production of masks, cosmetic peels, lotions, creams and other products.
Slimming crayfish
The dietary properties of cancer are influenced by three factors:
- low calorie content of crayfish meat;
- lack of fat;
- high protein content.
Many diets, especially protein ones, strongly recommend crustacean meat in their menu. After all, not only is it a natural source of protein, it also has such a low energy value. And all the same notorious chitosan, which, among other things, also promotes the breakdown of fats and their removal from the body, is very widespread as a component that is part of weight loss drugs.
conclusions
River cancer is an effective, tasty and healthy product widely used in medicine, cosmetology, dietetics and, of course, cooking. It is characteristic that the entire freshwater inhabitant enjoys success. Both its meat, a useful source of easily digestible protein, and the tough chitinous shell that covers the entire body are highly valued. Due to the fact that one of the components of this shell is chitosan – just a magical component that has important medicinal properties and luxurious cosmetology. Eating crustaceans helps to strengthen blood vessels and joints, is the prevention of arthritis, arthrosis and thyroid diseases, strengthens the walls of blood vessels, and prevents cardiovascular diseases.
In cosmetology, it is the preparations containing chitosan that are highly valued: moisturizing creams and lotions with a deep hydration effect, anti-aging masks and peels, and many other products. Also, crustaceans are very effectively used in all kinds of diets, as a high-protein product with a low energy value. For example, the Ducan diet allows and even recommends eating crustacean meat in unlimited quantities on protein days. And chitosan has a unique ability to absorb fat molecules, literally absorb them, preventing them from accumulating in the body. Therefore, on its basis, many dietary supplements and preparations have been developed that promote weight loss. But at the same time, crayfish can cause an allergic reaction, so they should not be consumed by people prone to allergies, especially to fish and seafood. You also need to take into account the fact that eating a stale product can lead to indigestion or poisoning.
I would also like to mention the high cost of crayfish. There is not very much meat in one individual, it is mainly contained in the abdomen, and quite a bit in the claws. And the price is amazingly high. Delicious soups, sauces, and various gravies are prepared from crustacean meat. But the most common and beloved by everyone is with beer. However, it is worth noting that the dietary properties of this product will then have to be forgotten.
