Some crayfish are loved to be consumed with beer, others are looked after in aquariums, but few people remember that these creatures managed to survive for 130 million years, practically without changing their structure. The only thing that distinguishes them from their ancient counterparts is their size. During the Jurassic period, some types of crayfish reached 3 m in length and could stand up for themselves.
Today, there are about 55,000 representatives of the most varied lengths in the ranks of crustaceans, living in sea or fresh water, and some of them prefer to be terrestrial.
History of the delicacy
Crayfish have been used by people since antiquity, but then they were not served as a delicacy. It is obvious that healers and healers of the ancient world knew about the beneficial properties of the shells, as they made drugs from the bites of poisonous insects.
The first mention of river crayfish being a tasty dish was recorded in the 16th century, when one of the Swedish kings accidentally tasted them. Immediately a decree was issued for the peasants to catch and deliver them to the royal table, but did not dare to eat them themselves under pain of the death penalty.
Imitating the king, the Swedish nobles did the same, although the royal decree was perplexing for the poor people. They did not consider crayfish food and were content with them only in times of famine, which was extremely rare in this country.
In modern Sweden, there is even a national holiday, Day of Eating Crayfish, when people gather in large companies, boil these arthropods and drink strong liquor.
Today, some types of crayfish (the photo shows this) are considered a delicacy and are not just served with beer, but soups, salads are prepared from them, stewed with vegetables, sauces are made from them and even fried.
Their meat is considered one of the most environmentally friendly, despite the fact that they are sewers and "orderlies" of water sources. This is due to a balanced, self-purifying organism given to them by nature.
River arthropods
There are different types of crayfish, but this name is not entirely accurate, since they live in swamps, ponds, lakes, and artificial reservoirs. It is more correct to use the term "freshwater".
All representatives of crustaceans living in fresh water have the same structure:
- their body can reach a length of 10 to 20 cm;
- the upper part of the body is called the cephalothorax;
- they have an elongated and flatter abdomen;
- the body ends with a caudal fin;
- they have 10 thoracic legs and gills.
The most famous types of freshwater crayfish are:
- Broad-toed (Astacus astacus) lives in the reservoirs of Western Europe and the high mountain rivers of Switzerland, prefers places with temperatures from +7 to +24 degrees Celsius.
- Thin-toed (Astacus leptodactylus) can live both in fresh running or stagnant water, and in brackish water with a maximum temperature of up to +30.
These types of crayfish are not suitable for keeping in aquariums, as they are very demanding in care, especially in terms of water filtration and temperature conditions.
Florida cancer
Well-known to many aquarists, the red Florida crayfish can actually be black, white, orange, and even blue. It lives both in swamps and flowing rivers, and in water meadows, and as the water subsides, it “leaves” into deep holes underground.
These are the most undemanding types of crayfish to the composition and quality of water. Their appearance is well known to the inhabitants of not only swampy Florida, but also Europe. Its distinguishing feature is the red spikes located on the claws.
This small arthropod (body length up to 12 cm) can easily tolerate water temperatures from +5 to + 30 degrees and breed year-round in an aquarium, laying up to 200 eggs. Incubation lasts for 30 days, and during this time the temperature in the aquarium should be maintained at +20...+25 degrees.
Red swamp crayfish get along well with fish, but remember that 1 pair will need an aquarium with 100 liters of water.
Blue crayfish from Cuba
Cuban blue crayfish may have other colors, as this directly depends on the natural conditions in their habitat and the color of their parents.
This tropical representative of arthropods lives in Cuba and Pinos. It has a small body up to 12 cm (excluding claws) and has a completely peaceful character, so it can be kept in aquariums with moving or large fish.
The fact that this crayfish is unpretentious and breeds well in captivity makes it a favorite of many aquarists. For 2 or 4 blue Cuban crayfish, you will need a 50 liter container with good ventilation and water filtration.
The female of this species can lay up to 200 eggs at a time. For this to happen, it is better to transplant the crayfish into another smaller aquarium before mating, so that there is no interference from the “neighbors”. Incubation lasts 3 weeks, during which the water temperature should be +25 degrees.
marine arthropod
The most popular among gourmets is lobster meat. These marine types of crayfish differ from their freshwater counterparts only in size and weight. They have a strong chitinous shell, which young individuals change as they grow older.
The molting of the lobster takes from 2 to 4 weeks, during which he is defenseless and forced to hide from his enemies in secluded places. The process of getting rid of tight coverage is interesting. The shell bursts on the lobster's back like a piece of clothing that is torn at the seams. To free itself, the cancer has to come out of it with its back, taking out one leg after the other.
The female lobster lays up to 4,000 eggs on her tail, after which the male fertilizes them. The incubation period lasts 9 months, during which the eggs remain on the mother's body. Individuals that have survived 25 molts are considered ready for mating and eating.
Gourmets are well aware of the European, Norwegian and American types of lobsters. The cost of their tender, healthy, dietary meat starts from $ 50 per kilogram, and 100 years ago it was used as bait for fishing.
Land representative of arthropods
If you think about the question of what types of crayfish are, then few people will remember that there are unique individuals that can climb trees.
These are coconut crayfish (Birgus latro), living on the islands of the Indian and Western Pacific Oceans. During the day, these amazing creatures hide in the foliage of palm trees, and at night they descend to pick up fallen fruits or carrion from the ground. The islanders call these hermit crabs thieves, as they often pick up everything that they think is bad.
Although the coconut crayfish spends most of its life on the ground, it begins its life in water bodies, where females lay eggs, from which small and defenseless crustaceans emerge. To survive, they are forced to look for a protective covering for their bodies, which most often becomes some kind of shell.
After the young grow up, crayfish go outside and can no longer return to the aquatic environment, as their gills atrophy, and ventilated lungs become respiratory organs.
Those wishing to see these unusual creatures will have to go to the tropical jungle at night. Their meat is considered a delicacy and aphrodisiac, but "hunting" for them is extremely limited.
Rare crustaceans
The rarest types of crayfish that can live in aquariums are called apricot. They live in Indonesia and can be either a delicate orange or blue, which is extremely rare.
They are small in size, males rarely grow to 10 cm, and the length of the female is 8 cm. To keep them in aquariums, you should not only make sure that the temperature regime is kept within +25 degrees, but the bottom should also be properly designed.
These crayfish love fine gravel sprinkled with bamboo, almond or oak leaves, which also serves as a good antiseptic. Numerous shelters in the form of snags, metal pipes and artificial houses will not interfere. For the most part, Orange Papua New Guinea lobster is a non-aggressive vegetarian, but it is still not recommended to “attach” small fish to it.
largest freshwater arthropods
The largest species of crayfish living in fresh water comes from Tasmania. In the rivers in the north of this Australian state, there are individuals reaching 60-80 cm in length with a weight of 3 to 6 kg.
Their favorite habitat is rivers with a calm flow, good air ventilation and a water temperature of +18 degrees. Depending on which river these giants live in, in the plains or mountains, they can have a color from green and brown to blue.
Since Astacopsis gouldi live up to 40 years and are considered long-lived among their relatives, all their life processes are somewhat delayed. For example, males are ready for breeding only at 9 years old, and females - at 14 years old, while they mate once every 2 years, and the incubation period lasts from autumn to summer of the next year. In this regard, it is customary for Tasmanian giants to keep a harem of females of different ages.
Heraxes
Another representative of the Australian rivers is the herax crayfish. Surprisingly, these arthropods, numbering many species, include individuals with completely different dimensions. So, some of them can be 40 cm long and weigh up to 3 kg, while others grow up to 10 cm and are placed in aquariums up to 20 liters. Another home for these freshwaters are the rivers of New Guinea.
It is easy to create conditions for keeping heraxes in an aquarium. They love warm water and the opportunity to dig in the ground, so if there are such “tenants”, it is better to plant plants in pots. They don't eat them, but they can dig them up. Herax crayfish are indifferent to the neighborhood of fish, but if you breed larger individuals with large claws, it is better to keep them in a separate container.
Unusual types of crayfish
Although in general arthropods are very similar in appearance, their ability to adapt and survive is strikingly different. For example, river marble crayfish reproduce asexually, and a similar phenomenon in nature is called parthenogenesis.
Females of this type of crayfish are able to clone themselves without involving males in the process. A similar phenomenon could previously be observed only in higher crustaceans, but never in small river specimens, reaching a maximum length of 8 cm.
In order for freshwater aquarium crayfish to take root, it is necessary to constantly maintain cleanliness in water that is well enriched with oxygen.
When choosing a container for such "residents", one should proceed from the parameters that 15 liters of water will be required for 1 individual of 6-7 cm. To make pets feel at home, you should properly arrange the bottom. You will need driftwood, gravel or sand, ceramic or metal cylinders, where crayfish can hide during the day.
Planting plants in a container depends on the type of cancer, as well as whether fish will be together with it. Otherwise, the maintenance of these individuals does not cause trouble, the main thing is not to forget to close the aquarium with a lid, otherwise you can find your pet on the bed.
