Hearing the word "cancer", we first imagine the animals that we eat a bit of beer without thinking about how interesting these creatures are in 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 on the mountain whistles." They are not able to whistle.
Crayfish are different: white, green, red. In this article, we will talk about who the blue cancer is (see photo above), in what places it is found and about everything interesting related to this animal. Many would like to get an answer to the question of how nature worked to create outlandish cancer.
Are there blue crayfish
So why are blue crayfish not like the others? The color of the carapace of these aquatic inhabitants is caused by genetic mutations. Blue color depends on living conditions and food. This can be observed if the blue crayfish are launched into another reservoir and fed with those products that their other relatives, after some time they will fade and their carapace will become a dirty gray color.
Coloring is provided by the dye astaxanthin. In the carapace of cancer, in combination with proteins, it 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 down, and the original color remains. An example of this is boiled cancer 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: Species
On the territory of the former USSR, there are eight types of cancers. These are wide-fingered, thin-fingered or narrow-fingered representatives of this family. Exotic species are the following species:
• Blue Cuban.
• Blue Florida.
• Australian.
Lovers of such exotic can find some species imported from Oceania and Australia. Widespread European and Far Eastern representatives of water inhabitants. The most valuable is the European wide-toed view of the data of the shell-like creatures of nature. They are known as “cervical necks, ” which have been used successfully 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 residents, who are quite large and do not hibernate.
Where are the crayfish
Arthropod prefers to be in clear waters. Especially demanding in this regard is crayfish. It lives in small calm rivers, does not neglect fast and full-flowing ones, it can be found in streams, lakes and reservoirs. He especially appreciates the river with a rocky bottom, which is a refuge for him.
Most crayfish are found in water bodies of the Black, Azov and Baltic Seas. This includes rivers carrying their waters to the sea from the western side. The water bodies of the eastern side are inhabited by narrow-toed crayfish. Only once their paths crossed on the Volga. This happened 30 years ago, then the "Asians" replaced the "Europeans".
Freshwater and color species are bred in aquariums, including blue crayfish. Tropical species in aquariums can successfully breed.
Florida
Florida blue crayfish represent a species of Prokambarus. There are other names - allen cancer, electric blue and blue cancer. The natural habitat is North America, Florida, where a blue electrician is found in lakes, swamps and ponds.
Being in a natural environment, blue Florida cancer is not blue at all; its carapace under such conditions has a brown color. The species of crayfish with a blue tint was bred in the USA in the process of hybridization, after which they spread to other countries.
Blue australian crayfish
These beauties come from South Australia, where they live in lakes, swamps and flowing water bodies. Quite peaceful creatures have several names - Australian river, Australian blue apple crab, that is, the destroyer. A freshwater carapace of this species diversifies the life of the aquarium.
The beauty of the blue apple is just a bit to admire! It is striking in its length, which is about 20 cm, not to mention the perfection of the shell. Cancer, like a medieval knight, is chained in powerful armor. The claws are huge, powerful, he always sets them in front of him. The blue cancer moves with the help of several pairs of legs, guided by its sensitive antennae.
The most interesting thing is that the yabbi, having excellent eyesight, recognizes all his relatives, remembers the places he has visited before. He has the habit in his free time of digging holes, as if to destroy the soil. From here came the name "destroyer."
The courage of a yabbi can be envied when he sees danger, he never hides, but meets an enemy with a counterattack, rising with open claws. Australian cancer prefers to live alone, having mink under a stone or snag. Hunts at night.
This representative of crustaceans molts. Having dropped the carapace, it can become prey for any predator. To prevent this from happening, the cancer sits in its hole until the new shell becomes solid. Interestingly, the apple has the ability to regenerate. A lost claw or leg grows over time. Life expectancy is more than 10 years.
Dwarf view
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 the painstaking work of breeders over many years. Mexican Dwarf Blue Cancer is the tiniest of all crayfish found in the aquarium. The color of the shell is blue with bright blue “marble” spots.
Male males are up to 2.5 cm long, females are slightly smaller. In males, claws are lanceolate elongated, this is different from females in which they are thick and short. Blue crayfish calmly looks at the living algae of the aquarium, does not eat them. For fish and shrimp is not dangerous, it is peaceful. It reproduces easily, bringing posterity four times a year.
Blue crayfish: captivity
Previously, few contained crayfish in the aquarium, now they are very successful. This also applies to blue crayfish, which contributes to their bright color and interesting behavior.
The aquarium must be closed, as the crayfish can escape. Water should be 5 cm below the edge. The volume of the aquarium is at least 100 liters. For design, snags, stones, from plants - moss and fern, as well as a variety of plastic tubes are suitable, in a word, all that is suitable for shelter. If this is not done, the crayfish will begin to prepare shelters themselves, tearing holes with the help of the tail and legs.
Particular attention should be paid to lighting the aquarium. In the summer, its duration should be at least 12 hours, in winter - about 9 hours. The nitrate content in water should be maintained at a level not exceeding 100 mg / l. Use perfectly clean water with oxygen content. Blue crayfish are peaceful in nature, if they receive enough food, other fish and plants are left alone.
Most often, aquarists settle in the "Blue Moon" crayfish aquarium. They are very large, beautiful. The color of the shell is dark blue, steel shade, white dots are noticeable on the claws. Males have a white spot on the lower part of the claws.
Blue Cuban cancer is also held in captivity. Its color is pure blue, but reddish-brown crayfish are found. The caudal fin and claws are quite powerful. Under natural conditions they live in Cuban reservoirs.
Important points
With an aquarium blue crayfish content, there are several important rules to keep in mind:
• Regardless of the size of the aquarium, 200 or 300 liters, it can contain only one pair of heterosexual crayfish. If you add a few more apples to them, conflicts will begin to arise.
• Dwarf blue cancer needs oxygen. In case of lack of water, in natural conditions it is selected on land. Since the cancer, while in the aquarium, cannot get to the surface, in this case it faces death. This must be remembered!
• Water should be changed at least once every 7 days, replacing one fourth of the total amount.
Is it possible to eat
Just think, cancer is pure meat! Is that possible? Quite possible. These carrion eaters received from nature as a gift of exceptional purity the body. They are able to clean not only water, but also the body of lovers to feast on their meat. Do not even ask if you can eat blue crayfish. Residents of all countries value crayfish as a delicacy.
Take, for example, the French. They consider crayfish to be the tastiest, and even set up industrial production for their cultivation. In countries such as England, Canada and the United States, there are aquarium stores for the sale of river inhabitants. Switzerland has launched the Crayfish Eating Day, of which China is the main supplier.
Not everyone is able to cook the right shell. Not all merchants own this art and feed their customers cancerous with a dull red carapace, sometimes even with an unpleasant odor. With this method of cooking, no dill is to be hoped for. In the old days, unfortunate traders were fined; in the taverns, the owners themselves monitored the correct process for cooking crayfish.
How to cook crayfish
The main condition for boiled crayfish to be tasty is that they need to be cooked alive. Asleeps accumulate toxic substances that can harm human health. Before sending shellfish to boiling water, it is necessary to wash it 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, the cooked crayfish will delight with a bright red, as if varnished, carapace.
Many consider redness to be the 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. Cancer must be saturated with broth to be tasty. The approximate cooking time, depending on the size, is as follows:
• Small crayfish - 25 minutes.
• An average of 35 minutes.
• Large crayfish - 45-50 minutes.
An important point is how much salt to add to the broth. It should be quite salty, two tablespoons of water will require one tablespoon of salt. Since cancer 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 in the broth in which they cooked, insist. This will give the meat a refined taste and tenderness. By the way, in the tail it is the most juicy and appetizing. You can store in the refrigerator up to two days, no more.
