Keeping and breeding aquarium crayfish at home was previously considered exotic. However, in recent years, their popularity among amateur aquarists has begun to grow. They are interesting, unpretentious in care, have a calm character and bright appearance.
Crustaceans in nature
Crayfish (Astacidea) belong to the order of decapod crustaceans, consisting of more than 100 species, many of which are suitable for keeping in aquariums. Under favorable conditions, they can live 2-5 years, giving a lot of joy to their owners.
In nature, creatures with carapace and claws live in both fresh and salt water bodies. In recent years, breeders have bred many types of crayfish that have brighter and more beautiful colors compared to their wild relatives.
The most interesting representatives of freshwater crustaceans belong to two families:
- Parastacidae (Parastacidae) - inhabit the rivers and lakes of some areas of South America, Australia, Madagascar and New Guinea.
- Cambaridae - the inhabitants of the Northern Hemisphere are surrounded by them, they are characterized by bright colors, and therefore they are ideal for aquarium maintenance.
Appearance and body structure
Aquarium cancer has a strong chitinous shell that covers the body completely and protects it well; there is a mustache on the head for touch. In nature, they have a dark green color. In the oral cavity are rounded teeth designed for grinding food. Black eyes planted on long stems look interesting. Claws have several functional purposes: they help to move around, grab prey and defend against enemies.
The tail represents several segments, rounded at the end. The body length is on average about 13 cm, but there are also giant species up to 50 cm long.
By their nature, crayfish are very calm, but they prefer loneliness and zealously protect their nest, because of which they can even fight. If the shelter in the aquarium is not enough, then they begin to dig holes with the help of legs and tail.
Molting
An interesting feature of such unusual animals is periodic molting, i.e., dropping of its carapace and subsequent hardening of a new one. The frequency of this procedure depends on age: young molt up to 8 times a year, adults - 1-2. Duration of molting in young people is several minutes, in adults - several days.
During the change of the chitin-calcium shell, crayfish eat poorly and hide, waiting for the hardening of the new shell. Sometimes during this period, problems arise that can result in death. It is not necessary to remove the discarded shell, because the host usually eats it on its own, making up for the lack of calcium in the body.
Aquarium Crayfish Content
At home, crayfish prefer fairly large freshwater aquariums, in which it is necessary to regularly replace it. 1 individual usually accounts for 15-40 liters of volume, depending on the variety and size. It is imperative to install an internal filter (on the external they can climb up) and clean the bottom, because the bottom is the accumulation of food residues, in which pathogenic bacteria can start.
For all types of crayfish in the aquarium, it is necessary to provide for various shelters that they are actively landscaping: sometimes they bury them and then rake them back. Various pipes, grottoes and caves are placed on top of the ground, which will serve as a shelter. In such a shelter, they often spend up to 15 hours a day. Especially important will be the place where you can hide during the molting period, when the new shell has not yet hardened. Sometimes this period lasts up to 10 days.
Water and aquarium amenities
All varieties of aquarium crayfish like hard water (pH 7-8.5, hardness 10-15º dH), which they need to restore the shell during molting. They do not tolerate the presence of ammonia and chlorine in water, therefore, before filling the tank, it must be defended or dehlorators used.
The optimum temperature for cancers is in the range of 18-26 º; they tolerate its increase or decrease very poorly. Therefore, on hot days, cooling may be required. Monthly, it is necessary to replace 0.25-0.5 parts of water in the aquarium, and for some species even weekly. Moreover, such a replacement often stimulates the inhabitants to start molting.
When arranging an aquarium, it should be possible that the crayfish can rise to the surface, for example, with oxygen deficiency. Why tall plants are planted, stones are laid out below. However, it is necessary to cover the container with a lid or glass, otherwise the tenants will scatter around the room.
Crabs usually escape under the influence of negative conditions:
- polluted water;
- overpopulation in the "house";
- the influence of aggressive neighbors.
Soil and plants
The soil is poured into the aquarium with a thickness of at least 6 cm, given the love of crustaceans for digging holes. Pebbles are selected in different sizes, because residents will take them with claws. You can use sea pebbles, expanded clay or special primers, which are sold in stores.
Plants are selected with a strong root system (cryptocoryne, aponogetone, etc.), taking into account the love of crayfish for digging underground holes. However, they do not need to be fed, because crustaceans cannot stand the presence of chemical additives in water.
Crayfish nutrition
The basis of their diet in nature is plant food and plankton. Solving the problem of feeding captive aquarium crayfish is easy. Specialty stores sell special food for crustaceans in granules and tablets, which settle to the bottom: Tetra, MOSURA, Dennerle, etc.
In addition, they are given other types of food:
- beef hearts or minced meat;
- fish fillet and shrimp (fresh or frozen);
- vegetables (salad, cucumbers, zucchini, spinach, nettle, carrots), various aquarium plants;
- bloodworms, brine shrimp.
In order to improve digestion, it is recommended to give dried leaves of oak, beech and alder, which also protect their body from the appearance of parasites.
Feed should be 1 time per day in small quantities. The optimal feeding time is the evening when the crayfish go on a nightly “hunt”. The fish neighboring them at such hours are already less active and will not be able to deprive them of food, snatching it "from under the nose."
Cancer Species, Parastacidae Family
It is not recommended to keep ordinary crayfish at home together with fish, as they are able to eat them, and plants to spoil or pull out. However, there are species of aquarium crayfish developed by breeders that are designed specifically for keeping and breeding by amateur aquarists.
The largest species belong to the Parastacidae family:
- Australian red claw (Cherax quadricarinatus) - in nature, lives in New Guinea and Australia in irrigation canals, ponds and small rivers, completely undemanding to conditions. The size of the carapace is up to 20 cm, weight - up to 500 g, but in aquariums they do not grow to such indicators. The body is blue with a yellow speck; in males, the joints between the segments of the tail are red, orange or blue, the claws are powerful and large. Mature individuals have a cherry-red protrusion on the claws, for which they received the name. Ideal conditions for them would be: 150 liters per 2 individuals, water with a high pH level of 20-24 º. A layer of soil is recommended to be poured larger, placing many shelters (driftwood, pipes, pots, etc.). Diet: vegetables, oak and beech leaves, dry food, snails, earthworms, frozen fish.
- Zebra cancer (Cherax papuanus) is an inhabitant of New Guinean ponds, size - up to 15 cm, color - striped. Representatives of this species are more friendly, they can live even with small fish and shrimp. However, they like to dig everything up, pulling out the plants along with the roots. Lifestyle - at night, hiding during the day. You can add fruits and vegetables to the diet.
- Blue (Cherax tenuimanus) is a South Australian species, but its size (up to 40 cm) suggests that it is only in large containers (up to 400 l) with a temperature of +15 ... + 24 º. Especially colorful look bright blue specimens that are active even in the daytime.
Procambarus family: aquarium crayfish, photo and name
The following species belong to this family:
- Red swamp crayfish (Procambarus clarkii), which lives in the swamps of the American continent (Mexico and the southern US states). Size - up to 15 cm. This species easily adapts to any home environment and reproduces well, thanks to which arthropods at home were able to capture most of the water bodies, crowding out more peaceful inhabitants. Color - lilac black with bright red spots, you can also find the blue, pink, orange and red colors of the shell. For a pair of crustaceans, a 200-liter aquarium with a temperature of + 20-25 º is suitable, tolerates an increase to +35 º and cooling to +5 º. However, the males are very pugnacious, therefore they can not be planted together. The diet consists of worms, bloodworms, tubule, frozen fish, as well as leaves of trees and peas, dry food.
- Florida blue (Procambarus alleni) - its birthplace is swamps and lakes of Florida. Breeders brought out of the usual brown crayfish color with a bright blue shell, the length of which is no more than 10 cm. For keeping the pair, an aquarium of 100 l with a water temperature of + 18-28 º at pH 6.5-8 is suitable. For this species, it is necessary to replace half the volume of water every week. Large fish may be neighbors, but two males will not be able to get along.
- Marble aquarium crab (Procambarus Sp., Marble crayfish), also called "Yabbi", has a beautiful carapace pattern consisting of brown and green spots, as it grows older, the color darkens and becomes brighter. The body size is up to 15 cm. An original feature of the species is molting, in which the descended shell has even claws and a mustache, as well as their ability to reproduce without partners.
Russian aquarists also contain broad-toed and thin-toed crayfish, which differ in the size of claws, but they almost do not breed in captivity.
Dwarf species
Many crustacean lovers prefer to contain aquarium dwarf crayfish, they are very active and strong, they adapt well to the conditions of detention. Such representatives of 10-legs are painted in bright colors and easily become an adornment of decorative aquariums; they do not spoil plants so much compared to large crayfish.
The most common species of the Cambarellus family are peaceful and can be kept together with other inhabitants:
- Orange dwarf (Cambarellus patzcuarensis) or Mexican yellow Patzcuaro - reach only 6 cm in length and 4.5 males in males, an ideal option for them is a 70-liter container filled with plants and even fish. They have a pugnacious character, because they are not lodged with other species.
- Swamp dwarf (Cambarellus Puer) is painted in gray or brown-red shades, dark lines on the back are dotted or wave, in the center of the tail is a dark spot. Females grow to 4 cm, and males grow to 2 cm.
- Blue or baby (Cambarellus Diminutus) received a name for the minimum size (up to 2.5 cm) and peacefulness. The color is very effective: blue spots are scattered on a blue or green background, as seen in the photo of an aquarium cancer of this species. It has an interesting feature: it changes color depending on the feed and water components.
- Louisiana species (Cambarellus Shufeldtii) is the most quiet and secretive, the body is painted in shades of brown to gray with chaotic spots and stripes. Females are more blue in color and size.
- Mexican crab zubifar (Cambarellus Montezumae) - painted in brown spots, sometimes longitudinal stripes running along the back or abdomen, length - up to 5 cm. This species is also active in the daytime, it can be planted in general aquariums, but not with other decapods so as not to fight. However, the temperature of the content is lower.
Dwarf crayfish get along well with fish, however, it is better to select species that live in the middle and upper layers of the aquarium. It is not recommended to settle them with shrimps, as they will eat them. Within the cancer family, conflicts can often erupt when sharing shelters, if not enough.
Breeding crayfish
The mating procedure usually takes place immediately after moulting. During the mating dance, the couple makes movements with antennas and the body, and a stronger male holds the female by force, which tries to escape away at such a moment. Fertilized individuals hide in a shelter.
The further breeding period of aquarium crayfish depends entirely on favorable conditions and “maternal care”. After 20 days of gestation, the female lays eggs directly on her paws (pleopods), attaching them with sticky threads under the tail. The number of eggs for different species can be 30-1500 pieces. To avoid aggression from other inhabitants, it is better to put the female in a separate container.
When the younger generation appears, the kids continue to hold on to Mom’s belly. As they grow older, having survived the first molt, they begin to gradually acquire independence. For the comfort of young animals in the aquarium there should be more different stones, snags, for which they can hide. This will help them survive and avoid the attack of stronger individuals, as Due to uneven development, large crustaceans can eat the weak. During this period, mom can already be sent to another container.
Cancer Diseases and Pests
Among the crustacean pests:
- flatworms that enter the aquarium with snails;
- leeches;
- green algae that affect the gills.
Salt baths are used for treatment; it is recommended to reduce the number of inhabitants in the tank.
The most common diseases:
- Carapace disease - is recognized during molting, when a new chitinous shell does not harden within a day; its cause is the low hardness of water and poor nutrition, as a result of which the cancer body lacks calcium. For treatment, it is necessary to improve the conditions for keeping aquarium crayfish, as a preventive measure, drops for sea water with iodine are used, sold in a pet store (0.5 doses).
- Plague - is an infectious disease that causes the fungus Aphanomices astaci, which can kill all the inhabitants of the aquarium. At first, the disease manifests itself with white, brown-red and black spots on the legs and shell, then there is a disorientation, a change in lifestyle on the daytime, then - lethargy in behavior, convulsions and death. There is no cure.
- Rusty spotting - transmitted by pathogens fungi Mucedinaceae, which affect the upper integument, blood vessels and heart. Externally visible brown spots on the gills and abdomen. The risk group includes decapods with reduced immunity, contained in adverse conditions or after injuries.
Crayfish compatibility
In one aquarium, combining crayfish and fish is quite difficult, because many of their species can eat each other. It is especially easy to do this with armored animals, which are able to bite small fish in half with claws. Moreover, they go hunting at night, and in the morning the number of inhabitants in the aquarium can decrease dramatically.
And large fish, for example, cichlids, can easily tear cancer, especially during molting, when the shell is weak. Good compatibility of aquarium crayfish with fish is inherent only to dwarf species of 10-legs, which are non-aggressive.
The dense vegetation in the aquarium is also not very suitable for crustaceans, which simply use it as food or dig it up. The only species that does not consume the underwater flora is the Mexican dwarf.
The maintenance and breeding of aquarium crayfish is a very exciting process, whose fans have been increasing in recent years. They are very interesting as objects of observation.