Earlier, the Australian red claw crayfish was known in Russia only to aquarium lovers. Today this arthropod is successfully grown on an industrial scale. We will learn how to breed exotic crayfish, how to feed it, and how to create optimal living conditions.
Description of the species
Thanks to its original appearance, the Australian crayfish has become a regular in decorative aquariums, and its tender meat and rapid growth have made it a profitable breeding object. We will find out what this inhabitant of the southern waters looks like, and what features it has.
Appearance
The second name of the red claw crayfish is Yabbi Red Claw. But the main color in the coloration of this cancer is blue. Among the predominant shades are green, brown, blue, orange, red. There are yellow blotches on the shell.
The color brightness of the Australian crayfish is directly related to the hardness of the water. The higher the indicator, the brighter the arthropod carapace. In soft water, the crayfish shell turns pale.
Characteristics of Australian Cancer:
- length - up to 20 cm
- weight - up to 0.4-0.5 kg;
- the lifespan is 5 years.
Character and behavior
Australian crayfish are non-aggressive. But their behavior is significantly influenced by their environment. Under certain circumstances, arthropods begin to show hostility.
Features of the behavior of red claw crayfish:
- get along well with all types of fish, agree to share dwellings with them;
- often conflict with each other;
- cannibalism is possible.
In nature, red-clawed crayfish tear out holes for shelter with their claws. They also hide under snags and between the roots of coastal plants. They go hunting at night, during the day they prefer to sleep. If crayfish go out for a walk during the daytime, then they are moulting.
In nature, Australian cancer eats:
- detritus;
- worms;
- snails;
- small fish.
Detritus is a dead organic substance consisting of the remains of invertebrates and temporarily excluded from the cycle of biological nutrients.
Sexual characteristics
The readiness of males for mating is indicated by a flat thickening on the outer sides of the claws. It can be white, pink, but more often it is red. By these marks, "claws" in honor of which the Australian crayfish got its middle name, males can be easily distinguished from females.
Females have neat claws, without protrusions. In size, males are somewhat larger than females.
Reproduction
When breeding, the ratio of males to females ranges from 1: 1 to 1: 4. Sexual activity, the duration of the incubation period and the growth rate of fry are affected by the water temperature. The optimum value for spawning and development of eggs is + 25 ... + 28 ° С.
The recommended ratio of dark and light time is 12/12 or 10/14 hours. For breeding, ponds are used in which it is easy to manage broodstock. The density of crayfish is 1.5 thousand per hectare.
The largest and strongest individuals are chosen for the role of producers. The fertility of one female weighing 100 g is 1 thousand crustaceans. Optimal parameters of the mother pond:
- area - 1,000 sq. m;
- depth - 1.2-2.5 m;
- bottom profile - V-shaped.
The duration of bearing eggs and larvae in a female Australian crayfish is 8-9 weeks.
Meat yield
Australian crayfish are raised for meat. The business is profitable due to the low investment and the rapid growth of arthropods. Biological and fish-breeding indicators:
- marketable weight of one copy - 200-400 g;
- weight gain - 50-60 g in six months;
- the amount of meat in the tail is 30% (in other crayfish - no more than 20%).
With the industrial cultivation of red claw crayfish in the southern regions of Russia, it is possible to grow individuals weighing 200 g or more in 4 months. Common crayfish reach a weight of 100-120 g in 10 years of life.
Taste of meat
Australian crayfish taste significantly different from domestic river analogues. Their meat has a special texture, it is more tender, with coarse fibers. Experts say that red claw crayfish meat resembles lobster in structure, and crabs in taste.
The meat of Australian crayfish is harmoniously combined with different ingredients. In restaurants, it is usually served in combination with various river delicacies or sauces to enhance the flavor of the meat, which is prepared using the same technology as lobster.
Red-clawed Australian cancer meat is dietary, it is recommended to eat it for people with diseased vessels and circulatory disorders. 100 g of meat - 80 kcal.
Habitats in nature
The habitat of the red claw Australian crayfish is stagnant waters in the Australian region. This representative of arthropods is found on the Australian continent and in New Guinea.
Cancer prefers to live in water bodies where there is no current, or it is minimal. Habitat:
- ponds;
- shallow rivers;
- lakes;
- streams.
It is living in stagnant water that allows you to keep Australian crayfish in closed reservoirs and aquariums.
Breeding crayfish
Today, Australian crayfish is becoming a promising target for industrial cultivation. Growth parameters and other characteristics of red claw crayfish allow you to create a profitable business for their breeding.
Where are crayfish grown?
For breeding crayfish, a system of shallow ponds is created - incubation, brood, nursery, feeding. Some of the ponds are covered with polycarbonate. In them, the temperature in winter does not drop below +7 ° C, so that the crayfish do not fall asleep, but feed and gain weight.
In the brood ponds, eggs are overexposed. Growing ponds are made shallow - 0.5-1.5 m, with an area of 0.1-0.5 hectares. It is desirable that there is a discharge of water in them - a waste collector is installed in it.
Features of the arrangement of a reservoir for growing crayfish:
- the pond is filled with water a couple of weeks before the crayfish plant;
- walls in such reservoirs are made vertical;
- the bottom is lined with polypropylene - it does not rot, helping to maintain the purity of the water;
- crushed stone, broken brick, ceramic waste with a layer of 20 cm are applied to polypropylene, and a layer of sand 10 cm thick on top.
Crayfish are also grown in recirculated water supply systems, which include:
- crustacean pools;
- water treatment unit;
- bio-filter;
- water treatment unit.
The water temperature in the pools is maintained by split systems.
In pools for crayfish, artificial holes made of plastic pipes are arranged. These havens help prevent cannibalism.
Neighbors and vegetation
Red-clawed crayfish are able to get along with different types of fish, so small non-predatory species can be launched into ponds. After crayfish, there are many food residues, and thanks to the small fish that eat them, it is possible to maintain the purity of the water.
It is impossible to breed large and predatory fish in ponds with crayfish, as they are capable of eating small crayfish.
The flora of the ponds is standard. Cancers love plant foods. The more plants in the reservoir, the better. Moreover, these arthropods not only eat the leaves, but also damage the roots when they dig them up.
Requirements for the reservoir
Australian crayfish are undemanding to water quality, so there are no particular problems when creating crustaceans.
Optimal conditions of detention:
- active reaction - in the range of pH 6.5-8.5;
- hardness - from 5 to 20;
- temperature - + 20 ... + 28 ° С;
- minimum / maximum permissible temperature –10 / 36 ° С.
Cancers, unlike shrimps, are able to survive in the most unfavorable conditions - with a low oxygen content and a high concentration of nitrates. Copper ions are the most dangerous for cancers.
Feeding regimen and diet
Cancers in nature eat everything that comes their way. Their nutrition in artificial breeding should be varied, complete, rich in proteins. Combined feed helps to solve the problem of nutrition. Crayfish are fed 2-3 times a day.
Combined feed, chalk, proteins, bloodworms, earthworms are added to ordinary food. Before adding a new portion of feed, check whether the feeders are empty.
The diet of young animals should include:
- snails;
- larvae;
- daphnia;
- cyclops;
- water worms;
- fish fry.
Young crayfish willingly eat minced meat. As it develops, the diet becomes more varied. To prevent the crayfish from eating each other, meat, fish, vegetables, bread, cake and even frogs are introduced into their diet.
The daily feed rate is 2% of the body weight of the arthropod, for females - 4%.
For crayfish to grow well, their food must contain a variety of components of plant and animal origin, minerals and vitamins. Foreign compound feed for shrimps is helping to solve the nutrition problem today.
The optimal composition of branded crayfish food:
- proteins - 43%;
- fats - 8%;
- fiber - 4%.
Also suitable for crayfish are industrial pelleted feeds of imported production, intended for aquatic organisms (fish, molluscs, crustaceans, etc.).
Optimal food ratio:
- vegetable - 70%;
- animal - 30%.
It is recommended to add dry leaves, ground stems, reeds to food. In the diet of Australian crayfish, beech or oak foliage must be present. This dish for red-clawed arthropods is not only a delicacy, but also an antiseptic necessary for their immune system.
What shouldn't be fed?
Although red-clawed crayfish are considered omnivorous, there are foods that are best avoided:
- banana peel;
- grated beets, carrots, potatoes - they spoil the water;
- crayfish do not eat apples.
It is not recommended to litter the crustacean basins with minced meat, eggs, cottage cheese, food scraps, if the water is not cleaned and filtered.
Breeding procedure on farms
To create a mini-farm for breeding crayfish, a small plot and minimal costs are enough. The duration of growing crayfish for sale is a year and a half. The invested funds pay off within a year.
Artificial breeding procedure:
- In October-November, females are transferred to the brood pool. In June, newborn crustaceans appear - they are kept in incubation tanks.
- To ensure the safety of the larvae, in May, the eggs are harvested and removed by means of the Weiss apparatus. One 8 L incubator can hold up to 15,000 eggs.
- After the second molt, the crayfish are transferred to nursery ponds, where they are grown at + 22 ... + 24 ° C up to 8 cm in length and up to a weight of 15-18 g.
- Yearlings are transferred to feeding ponds, where they gain a mass of 40-60 g.
Mass production of crayfish requires a lot of investment. Prepare a whole system of pools or tanks, climate control and water supply.
Breeding tanks for crayfish must be large enough. If crayfish are cramped in them, they eat each other. Separate tanks are provided for the young, otherwise they will also be eaten.
Compared to many other aquatic organisms, these arthropods are unpretentious, grow very quickly and provide a large yield of valuable meat. These features of the red claw Australian crayfish make them a very attractive target for commercial breeding.
Author of the publication
12
Russia. City Novosibirsk
Publications: 276 Comments: 1