When we hear the word "cancer", we first imagine the animals that we eat as a snack on beer, without thinking about how interesting these creatures are by nature. They sometimes climb high into the mountains, settling in streams and rivers, but they will have to wait a long time, "until the cancer whistles on the mountain." They are unable to whistle.
Crayfish are different: white, green, red. In this article, we will talk about who blue cancer is (see photo above), in what places it is found, and about everything interesting related to this animal. Many would like an answer to the question of how nature worked to create outlandish cancer.
Are there blue crayfish
So why aren't blue crayfish like the others? The color of the shell of these aquatic inhabitants is caused by genetic mutations. The blue color depends on living conditions and food. This can be observed if blue crayfish are launched into another body of water and fed with the same products as their other relatives, after a while they shed and their shell becomes dirty gray.
Coloring is provided by the dye astaxanthin. In the shell of cancer, he, in combination with proteins,forms yellow, green, blue, almost black and blue pigments. In its pure form, astaxanthin is red-orange in color. In boiling water, the proteins coagulate, the compounds with the dye break up, the original color remains. An example of this is that boiled crayfish is always red. Under natural conditions, blue crayfish are found in the most remote regions of our planet. Their popularity is growing rapidly.
Blue cancer: types
There are eight types of crayfish on the territory of the former USSR. These are broad-toed, thin-toed or narrow-toed representatives of this family. Exotic species are represented by the following breeds:
• Blue Cuban.
• Blue Florida.
• Australian. Australia. European and Far Eastern representatives of aquatic inhabitants have become widespread. The European broad-toed species of these armored creatures of nature is considered the most valuable. They are known under the name "crayfish necks", which has been successfully used in cooking. Now this species is listed in the Red Book.
Species are divided into lake and river. Growing crayfish at home, preference is given to lake dwellers, who are quite large in size and do not hibernate.
Where the crayfish are found
Arthropod prefers to be in clean water. Particularly demanding in this regard is crayfish. It lives in small calm rivers, does not neglect fast full-flowing ones, it can be found in streams, lakes and reservoirs. Especially appreciates the rivers withrocky bottom, which is his refuge.
Most of all there are crayfish in the waters of the Black, Azov and B altic Seas. This includes rivers that carry their waters to the sea from the western side. The reservoirs of the eastern side are inhabited by narrow-clawed crayfish. Only once did their paths cross on the Volga. It happened 30 years ago, when the "Asians" forced out the "Europeans".
Freshwater and color species are bred in aquariums, including blue crayfish. Tropical species can breed successfully in aquariums.
Floridian
Florida blue crayfish represent Procambarus species. There are other names - Alleni cancer, electric blue and blue cancer. Habitat in natural conditions - North America, Florida, where blue electric is found in lakes, swamps and ponds.
In its natural environment, the blue Florida crayfish is not blue at all, its shell in such conditions has a brown color. A type of crayfish with a blue tint was bred in the United States through the process of hybridization, after which they spread to other countries.
Australian blue crayfish
These beauties come from South Australia, where they live in lakes, swamps and flowing waters. Pretty peaceful creatures have several names - the Australian river, the blue Australian yabbi crayfish, that is, the destroyer. Freshwater shell of this species diversifies the life of the aquarium.
You will simply admire the beauty of the blue yabbie! It impresses with its length, which is about 20 cm, not to mention the perfection of the shell. cancer likemedieval knight, clad in powerful armor. The claws are huge, powerful, he always puts them in front of him. Blue cancer moves with the help of several pairs of legs, guided by its sensitive antennae.
The most interesting thing is that the yabbie, having excellent eyesight, recognizes all his relatives, remembers the places he has visited before. He has a habit of digging holes in his free time, as if destroying the ground. Hence the name "destroyer".
You can envy the yabbie's courage when he sees danger, he never hides, but meets the enemy with a counterattack, rising with his claws open. Australian cancer prefers to live alone, arranging a mink under a stone or snag. Hunts at night.
This representative of crustaceans sheds. Having dropped the shell, it can become prey for any predator. To prevent this from happening, the cancer sits in its hole until the new shell becomes hard. Interestingly, the yabbie has the ability to regenerate. A lost claw or leg grows back over time. Life expectancy - more than 10 years.
Dwarf species
Habitat: Mexico, Lake Patzcuaro. Under natural conditions, the shell of dwarf crayfish is brownish or yellowish in color. Attractive blue color is the result of many years of painstaking work of breeders. The dwarf blue Mexican crayfish is the smallest of all crayfish kept in an aquarium. The color of the shell is blue with the presence of bright blue "marble" spots.
Baby males are up to 2.5 cm long, females are slightly smaller. In males, the claws are lanceolate, elongated, this differs from females, in which they are thick and short. Blue crayfish calmly looks at the living algae of the aquarium, does not eat them. It does not pose a danger to fish and shrimps, it is peaceful. It breeds easily, producing offspring four times a year.
Blue crayfish in captivity
In the past, few people kept crayfish in an aquarium, now they are very successful. This also applies to blue crayfish, which is facilitated by their bright colors and interesting behavior.
The aquarium needs to be closed, as the crayfish can escape. Water should be 5 cm below the edge. The volume of the aquarium should be at least 100 liters. Driftwood, stones are suitable for decoration, from plants - moss and fern, as well as a variety of plastic tubes, in a word, everything that is suitable for shelter. If this is not done, the crayfish will begin to prepare shelters themselves, tearing out holes with the help of their tail and legs.
Special attention should be paid to aquarium lighting. In summer, its duration should be at least 12 hours, in winter - about 9 hours. The content of nitrates in water should be maintained at a level not exceeding 100 mg/l. Use water that is perfectly clean with an oxygen content. Blue crayfish are peaceful in nature, if they get enough food, other fish and plants will be left alone.
Most often, aquarists settle crayfish "Blue Moon" in aquariums. They are very large and beautiful. The color of the shell is dark blue, steel shade, on clawsvisible white dots. Males have a white spot on the underside of their claws.
The Blue Cuban Crayfish is also kept in captivity. Its color is pure blue, but there are reddish-brown crayfish. The tail fin and pincers are quite powerful. Under natural conditions, they live in Cuban reservoirs.
Important points
There are a few important rules to keep in mind when keeping blue crayfish in an aquarium:
• Regardless of the size of the aquarium, 200 or 300 liters, it can contain only one pair of crayfish of different sexes. If you add a few more yabbies to them, conflicts will begin to arise.
• Dwarf blue crayfish needs oxygen. In case of its lack in water, in natural conditions it gets out on land. Since the cancer, being in the aquarium, cannot get to the surface, in this case it is threatened with death. This must be remembered!• Water should be changed at least once every 7 days, replacing one-fourth of the total.
Can I eat
Just think, cancer is pure meat! Is that possible? Quite possible. These carrion eaters received from nature a gift of exceptional purity of the body. They are able to purify not only water, but also the body of those who like to eat their meat. You should not even ask if you can eat blue crayfish. People of all countries value crayfish as a delicacy.
Take the French, for example. They consider crayfish to be the most delicious, they even set up industrial production according to theircultivation. In countries such as England, Canada and the United States, there are aquarium stores for the sale of river inhabitants. Switzerland has established a holiday "Crayfish Eating Day", the main supplier of which is China.
Not everyone is able to cook shellfish correctly. Not all merchants master this art and feed their customers crustaceans with a dull red shell, sometimes even with an unpleasant odor. With this method of cooking, there is no hope for any dill. In the old days, unfortunate merchants were subjected to fines, in taverns, the owners themselves monitored the correct process of cooking crayfish.
How to cook crayfish
The main condition for boiled crayfish to be tasty is to cook them alive. Asleep accumulate toxic substances that can harm human he alth. Before sending the shells to boiling water, it is necessary to wash them properly, it is especially good to clean the place where the legs are attached to the body. Change the water until it becomes completely light, but it is better to carry out such a procedure under running water. After such a bath, boiled crayfish will delight with a bright red, as if varnished, shell.
Many consider reddening as a signal for the end of cooking, which is completely wrong. Everything will depend on the size, because these water inhabitants are small, medium, and there are also large ones. Crayfish must be soaked in broth to become tasty. Approximate cooking time depending on the size is as follows:
• Small crayfish - 25 minutes.
• Medium - 35 minutes.• Large crayfish - 45-50 minutes.
The important point is thathow much s alt to add to the broth. It should be s alty enough, one tablespoon of s alt is required for two liters of water. Since crayfish has a completely tasteless meat, a sufficient amount of spices, especially dill, should be sent to the boiling water.
At the end of the crayfish, you need to leave it in the broth in which it was cooked, to infuse. This will give the meat a delicious taste and tenderness. By the way, in the tail it is the most juicy and appetizing. You can store in the refrigerator for up to two days, no more.
Interesting facts
On the islands of the tropics live crayfish, which are called palm thieves. They pick up fallen cracked fruits, if there are none, they climb along with a whole coconut on a palm tree to throw it down and break it.
Cancer can protrude its eyes with the help of stalks, which helps it regulate vision.
Up to 30 thousand crayfish live in different parts of our planet, some of them have adapted to live on land. In the reservoirs of Tasmania, you can find crayfish 60 cm long and weighing 3-4 kg.
Rachiha can lay up to 600 eggs under its belly. It bears offspring much longer than river fish, this process lasts for half a year. Having been born, little racats immediately hide under their mother's tail. Blue cancer, like all others like it, is a very interesting, and at the same time quite tasty creation of nature. Man is faced with the main task - to save this species of arthropods on Earth.
