444 results about "Polyculture" patented technology

The invention relates to a mixed feed for mixed aquaculture of freshwater fishes. The mixed feed includes a basic material. The basic material includes fish meal, soybean meal, wheat, cottonseed meal, rapeseed meal and soybean oil, and also includes by weight: 1.5-2.2% of calcium phosphate, 1.5-2.2% of bentonite, 1.5-2.2% of zeolite powder, 0.1-0.25% of choline chloride, 0.1-0.25% of salt, 0.02-0.05% of compound probiotics, 0.04-0.08% of vitamin C, 0.005-0.02% of allicin, 1.0-2.0% of compound vitamins and 1.0-2.5% of compound mineral salts. The feed is suitable for intensive culture or polyculture of megalobrama amblycephala, black carp, grass carp, common carp and the like, so that the freshwater fish feed is generalized, the return rate of the feed is improved, the aquaculture water eutrophication and fish liver and gallbladder diseases are reduced, the output of unit aquatic products is raised, and the economic benefits of farmers are significantly improved.

The invention relates to an ecological trepang culture method in silt sandy ponds in coastlands, which belongs to the aquaculture field. The method comprises the steps of setting a pond, setting trepang reefs, disinfect the pond, controlling feed water, cultivating feedstuff, stocking young trepang and managing culture. The feedstuff culture which is performed in April to May comprises the following steps: firstly, transplanting benthic diatom in a height of 0.8 to 1 m feed water depth in the pond in the prior period, with 5 to 10 L of benthic diatom liquid per Chinese acre; secondly, transplanting ruppia maritime and amphilhoe japonice, especially, integrally transplanting ruppia maritime through pulling up by the roots according to the quantity of 5 to 15m per square meter, and transplanting amphilhoe japonica according to the quantity of 1.5 to 3 kg per Chinese acre after the transplanting of ruppia maritime; thirdly, poly-culturing mussel organism; fourthly, feeding water to the pond to the depth of 3 to 4 m, and stocking prawns according to the quantity of 500 to 1500 per Chinese acre. In the method of the invention, ecological feedstuff is adopted for transplanting and polyculture, therefore, not only the cost of artificial feedstuff is saved, but also the natural ecological environment is created for trepang culture.

The invention discloses a polyculture method of river crabs, crayfish and mandarin fish. The polyculture method of the river crabs, the crayfish and the mandarin fish comprises the following steps of building a pool, cleaning and disinfecting the pool, planting aquatic plants, putting snails into the pool, disinfecting seeds, putting the seeds into the pool, feeding fodder, regulating and controlling the water quality of the pool, and catching products. According to the polyculture method of the river crabs, the crayfish and the mandarin fish, which is provided by the invention, the effective control on the kinds, the total quantity and the specification of cultivation can be realized, the cultivation cost is reduced, and the economical benefit of the cultivation is increased.

The invention discloses a penaeus vannamei farming method combining bioflocculation technology and a multi-trophic-level integrated farming mode. The penaeus vannamei farming method combining the bioflocculation technology and the multi-trophic-level integrated farming mode includes the steps such as early-stage preparations of farming conditions, putting of penaeus vannamei and small-size fish, swamp cabbage planting, starch addition and feeding feedstuff management. According to the method, the multi-trophic-level integrated farming mode and the bioflocculation technology are innovatively applied to penaeus vannamei farming in a combining mode, namely, a multi-trophic-level integrated farming system composed of polyculture of the penaeus vannamei, the small-size fish and swamp cabbages. Starch is added in the farming system to serve as carbon source cultivation biological floccules. The levels of ammoniacal nitrogen and nitrous nitrogen in a water body are controlled through a bioflocculation action. Simultaneously, residual bait and excrement are utilized to form bacterium floccules which prawns and the small-size fish can ingest and utilize, and therefore the survival rate of the penaeus vannamei and the efficiency of feed utilization are improved. Relative to an ordinary single-farming mode, aspects of ecological benefits, economic benefits and farming effects in the farming system all achieve obvious effects.

The invention relates to a method for efficient polyculture of environmental-friendly fresh water fishes, shrimps and crabs. The method is characterized in that according to the existing water environment characteristics of an aquaculture water area, an organic ecological aquaculture mode based on a food chain is established, suitable aquatic plants, aquatic animals and bottom fauna are selected, and a self-circulation environmental-friendly ecological system without outside feeding is constructed. The method can achieve the high unification of economic, environmental and social benefits.

The invention discloses a multiple hybrid polyculture method of omnivorous and carnivorous fishes in an intensive prawn culture pond. The method includes pretreating pond water in a pond with a surrounding net at the center, putting prawn seeds in the pond for culture, putting omnivorous fish seeds in the surrounding net for culture, putting carnivorous fish seeds outside the surrounding net for culture, using an aerator to aerate the pond during culture, throwing feed in the area outside the surrounding net at times, and adding microbiological preparation to control water quality in mid-to-late period of culture. By the method, utilization rate of prawn feed can be increased evidently, excess accumulation of organic pollutants in the intensive prawn culture pond is relieved effectively, the problem of low utilization rate of center space of the intensive prawn culture pond can be solved, infectious prawn diseases can be controlled to a certain degree, various advantages of fish and shrimp polyculture are given to play, and success rate of prawn culture is increased greatly.

A method for producing a biogas is provided. The method includes the steps of providing a polyculture of aquatic plants to a growth system; continuously providing water, carbon dioxide, air and nutrients to the polyculture contained within the growth system; growing the polyculture for a time sufficient to produce an aquatic plant-based biomass; withdrawing a portion of the aquatic plant-based biomass contained within the growth system; and treating the withdrawn aquatic plant-based biomass to produce a biogas.

A composite forage for green shrimp and river crab is prepared from 18 raw materials including wheat flour, fish powder, soybean cake, fish oil, choline chloride, etc.

An indoor-outdoor multi-crops polyculture method for shrimp, soft-shelled turtle and fish includes building an upper greenhouse culture pond and a lower outdoor intensive culture pond, and using a transfer pipe to communicate the upper greenhouse culture pond and the lower outdoor intensive culture pond; throwing desalted giant tiger prawn in the upper greenhouse culture pond in mid-March, and keeping water temperature at 25 DEG C; pouring water into the lower outdoor intensive culture pond prior to throwing in silver carp, bighead carp and Chinese soft-shelled turtle for breeding in early May; after seedlings grow to about 5cm 50-60 days after culture of the giant tiger prawn in the upper greenhouse culture pond, transferring young shrimps in the upper greenhouse culture pond into the lower outdoor intensive culture pond for breeding through the transfer pipe, harvesting first crop from late June to early July; and harvesting the silver carp, the bighead carp and the Chinese soft-shelled turtle in November to December after continuous three-crop culture of the giant tiger prawn. The indoor-outdoor multi-crops polyculture method for shrimp, soft-shelled turtle and fish breaks through the bottleneck of existing culture production and benefit.

The invention discloses an ecological breeding method of efficient polyculture of pseudorasbora parva, crab larva and loach. The method comprises the steps of: pond conditions, disinfection, breeding water preparation, grass planting, fry breeding, water level adjustment, water quality adjustment and control, feeding management, disease control, daily management and the like. The breeding method provided by the invention focus on the breeding of crab larvae; the pseudorasbora parva is mainly used as cleaners for residual feeds, so that the pollution to water quality can be greatly reduced, the water quality can be improved, the growth of crab larvae and loaches is promoted, and meanwhile, blue-green algae outbreak in the crab larva pond can be biologically controlled by the polyculture of the pseudorasbora parva; the loaches play a role in loosening the soil, and eliminates hazardous substances in the soil in time, so as to avoid the water quality becoming bad due to the high temperature in summer, in addition, loaches do not need additional feeding and management, are beneficial supplement to the breeding of the crab larvae, and thus the pond benefit is greatly increased.

The invention discloses an ecological remediation type marine ranch and a construction method for the same, and belongs to the technical field of marine ecological environments. The marine ranch comprises more than one multifunctional unit culture platform, wherein each multifunctional unit culture platform comprises a lifting and submersible ecological unit culture platform frame consisting of a U-shaped main floating pipe and more than one HDPE (High-Density Polyethylene) junction pipe; the two ends of each U-shaped main floating pipe are closed, and each U-shaped main floating pipe is formed by bending a large-diameter HDPE pipe; the two ends of each HDPE junction pipe are closed; alga bed areas, open box type precious marine product polyculture areas, settlement devices and anchorage devices are arranged on the platform frames. According to the marine ranch and the construction method, the multifunctional unit culture platforms have a lifting function, and can float to the water surface and stay in different underwater layers, so that the photosynthesis of algae is facilitated, and high growth speed is ensured; by the open box type ecological polyculture of precious marine products such as algae, abalones, cucumbers, oysters and mytilidae, a marine resource remediation function is realized, and good ecological benefits and economic benefits are created.

The invention provides an imitated natural habitat river type domesticating method for wild rhinogobio ventralis. The method comprises the steps of 1) building an imitated natural habitat river; 2) preparing for staged water quality control; 3) performing polyculture and matching for fishes; 4) feeding wild rhinogobio ventralis to be domesticated to an imitated river domesticating pool; 5) regulating and controlling the water quality in the early stage of domesticating; 6) feeding bait in the early stage of domesticating, namely, feeding living food to the imitated river domesticating pool at the early stage of domesticating of wild rhinogobio ventralis; 7) regulating and controlling the water quality in the middle and later stage of domesticating; 8) feeding bait in the middle and later stage of domesticating, so as to finish the domesticating of wild rhinogobio ventralis in the imitated natural habitat river. With the adoption of the imitated natural habitat river type domesticating method for wild rhinogobio ventralis and a cruise pool, the problem that the fishes like wild rhinogobio ventralis living in running water habitat are difficult to domesticate artificially can be effectively solved, a domesticating mode meeting the growth and development demand of wild rhinogobio ventralis is created, and the technological foundation is provided for artificial breeding of population.

The invention relates to a crawfish organic ecology culture method comprising the following steps: building two or three of the following modules: a pond culture module, a rice field culture module and a lotus rhizome field culture module; digging gutters in rice field culture units and lotus rhizome field culture units; using separation dams and trenches to build a circulating water system; planting waterweeds in the pond; using a sectioned catching and stocking rotation mode to culture crawfish in the pond; carrying out crawfish-rice organic polyculture in the rice field culture units, and transferring crawfishes to the gutters or other modules for re-culture in a rice field sorting process; carrying out crawfish-lotus rhizome organic polyculture in each lotus rhizome field culture unit, and transferring the crawfishes to other modules for re-culture in a lotus rhizome leaf initial grow period. The crawfish organic ecology culture method can realize nutrients cycle complementation utilization, can ensure water body oxygen dissolving, can prevent medicament application, and can realize crawfish nature transition transfer between rice field culture and lotus rhizome field culture, thus finally realizing high yield, high quality and environment friendly organic ecology culture.

The invention discloses a shrimp, crab and mandarin fish polyculture method, which includes pond construction, clearing and disinfection and shrimp seed stocking; pond construction means that an old pond is altered or a new pond is dug, so that the culture pond can come up to various indexes of standardized fish pond construction; clearing and disinfection mean that after old pond silt clearing, pond embankment leakage prevention and reinforcement, new / old fish pond escape-proof facility arrangement, pond insolation and other works, the whole pond is thoroughly disinfected; the quantity of stocked shrimp seeds is 10 kilograms of freshwater shrimps per mu, and the specification is 1000 to 1400 post-winter shrimp seeds per kilogram; the quantity of stocked silver carp seeds and bighead carp seeds is 30 to 50 per mu; the area of planted waterweeds is about 50 percent of the area of the pond; the quantity of migrated snails is 230 to 260 kilograms per mu; preferably, the quantity of stocked juvenile river crabs is 500 to 800 per mu; preferably, the quantity of stocked loaches is 350 to 450 per mu; and preferably, the quantity of stocked yellow catfishes is 250 to 350 per mu. The method covers the shrimp, crab and mandarin fish polyculture technique and the high-efficiency polyculture technique for a variety of fishes, and forms a unique feasible technical operation route, the polyculture mode is novel, the economic benefit is high, and the ecological environment is good.

The invention provides a mixotrophic-cultivation system in a freshwater pearl mussel pond, which comprises a pond, a separation device, a pearl mussel mixotrophic-cultivation region and an intensive fish cultivation region. The invention also provides a method for cultivating the pearl mussel by the mixotrophic-cultivation system. The mixotrophic-cultivation system and the method make full use of the nutrition relation among the mixotrophic-cultivation species, which reduces nutrition collecting volume; by regulating water quality and water transparency as well as regulating composition of species of phytoplankton and biomass, nutrient salt, phytoplankton and level of dissolved oxygen of the water can be effectively and conveniently controlled, which can effectively keep a good ecological environment of the water. The mixotrophic-cultivation system and method of the invention can obviously accelerate growth of the pearl mussel and increment speed of the pearl.

The invention provides a reed-fish-shrimp-crab ecological polyculture method for inland soda saline-alkaline reed swamps, which includes crab acclimation, stocking densities of fries, juvenile shrimps and juvenile crabs, culture management and catch and reed culture. After the method is adopted, the survival rate of acclimated crabs is 81.3 percent; the average stocking densities of river crabs, fishes and shrimps are 2138 river crabs / hm<2>, 510 fishes / hm<2> and 11750 shrimps / hm<2>, the average catch weights of the river crabs, fishes and shrimps are 87.15kg / hm<2>, 233.30kg / hm<2> and 52.88kg / hm<2>, the average catch specifications of the river crabs, fishes and shrimps are 145.2g per crab, 670.6g per fish and 5.3g per shrimp, the average recapture rates of the river crabs, fishes and shrimps are 26.83 percent, 69.45 percent and 83.63 percent, the average density of reed is increased by 9.69 percent, the average yield is increased by 12.47 percent, and the input-output ratio of the experimental area is 1:3.174.

The invention discloses a wild rhinogobio ventralis continental rise pond net cage domestication method. The method includes four key technical links of the link 1, domestication pond water quality cultivation and regulation and control, specifically, applying liquid state organic fertilizer, composite probiotics and bottom material improvers at regular intervals to carry out water quality cultivation and the regulation and control, the link 2, net case establishment, and specifically a net case is mainly composed of knotless netting and a stainless steel framework and meanwhile is provided with an aeration flow generating device, the link 3, polyculture of wild rhinogobio ventralis and megalobrama pellegrini, specifically, adopting the method that artificial culture breeds are cultured in a matched mode outside the net cage to carry out domestication of wild fishes, and the link 4, ingestion domestication, specifically, adopting the method of food calling first and domestication feeding second, namely, feeding biological baits first then gradually feeding artificial mixed feed. According to the method, domestication of the wild fishes is carried out in a manner that the flow generating type net case is erected in a continental rise pond, meanwhile, the technologies of the water quality regulation and control, polyculture and live bait food calling are utilized comprehensively, and therefore the adaptability of the wild fishes to the culture environment can be promoted, the survival rate of domestication can be improved, and the method has wide application prospect.

The invention discloses a plant alga, zooplankton and fish automatic culture integrated device. Zooplankton, plant algae and fishes are separated through micro-filtration membranes for integrated culture, the food chain unbalance problem existing in polyculture is avoided, and convenience is brought to use; oxygen and carbon dioxide are mutually communicated to meet survival conditions required by internal animals and plants. Water resources are saved by means of a water circulation filtering mode, and a sterilizer in a water circulation module can be used for disinfection and sterilization to guarantee water quality. A magnetizer can convert large molecules into small molecules, water molecules can permeate the micro-filtration membranes more quickly, and the high content of dissolved oxygen in magnetized water makes the survival rate and quality of the animals and the plants improved. Excrement of the zooplankton and the fishes is collected and fermented and then serves as fertilizer of the plant algae for circulation, and the excrement is independently fermented to prevent water from being polluted and meanwhile can be absorbed and used by the plant algae more easily.

The invention discloses a novel high-efficiency environment-friendly fish and shrimp polyculture feed, and aims to provide a fish and shrimp polyculture feed which is easy to prepare and is balanced in nutrition. According to the technical scheme, the novel high-efficiency environment-friendly fish and shrimp polyculture feed comprises the following components: 7-24 percent of bean pulp, 3-8 percent of peanut pulp, 9-15 percent of cotton seed mill, 5-20 percent of rapeseed meal, 1-3.5 percent of cuttlefish paste, 12-17 percent of dried white vinasse, 6-8 percent of rice bran, 15-25 percent of flour, 0.5-1.5 percent of lecithin powder, 2-3 percent of monocalcium phosphate, 1.5-3 percent of bentonite, 0.03 percent of a mildew preventive, 0.03-0.05 percent of allicin, 0.2-0.3 percent of composite vitamin, 0.1 percent of choline chloride, 0.08 percent of potassium chloride, 0.02-0.05 percent of vitamin C, 0.1-0.3 percent of crystal lysine, 1-2 percent of beer yeast, 0.05-0.1 percent of shell element and 1-2 percent of composite mineral. The novel high-efficiency environment-friendly fish and shrimp polyculture feed belongs to the technical field of fish feeds.

The invention discloses a method for freshwater fish polyculture through Chinese herbal medicine. The method includes the steps of cleaning a pool, breeding fries outside freely, throwing bait for feeding fishes periodically, conducting water quality management and the like. Through the method, the method for fish polyculture is green and environmentally friendly. Due to the fact that Chinese herbal medicine composition contained in feed is mutually synergetic and complementary, the method has the effects of being resistant to microorganism, virus, parasite, and fungus, and improving immunity, and can effectively accelerate growth and development of fishes. Meanwhile, the toxic and side effects of the Chinese herbal medicine are little, pollution to the environment is little, taste of fish flesh is not affected, and the method is suitable for feeding of chub, grass carp and crucian carp.

The invention discloses a grass carp and crucian carp polyculture expanded feed and a preparation method thereof. The feed comprises the following components in percentage by weight: 5 to 15 percent of fermented soybean meal, 20 to 30 percent of rapeseed meal, 3 to 10 percent of coconut meal, 5 to 10 percent of palm kemel cake, 4 to 9 percent of distillers dried grains with soluble (DDGS), 3 to 9 percent of kelp residues, 15 to 40 percent of wheat middling, 0.5 to 1 percent of calcium hydrophosphate, 1 to 2 percent of premix for omnivorous fish, 1 to 3 percent of fish oil, 0.2 to 0.5 percent of crystal methionine, and 0.5 to 1.0 percent of crystal lysine. The polyculture expanded feed can float on the water surface, so that enough ingestion time is provided for cultured fish, the waste of the feed is reduced, meanwhile, the feed expanded at high temperature has high stability in water and difficultly pollutes culture water.

The invention discloses a water quality detection and sampling device for shrimp and crab polyculture in a park paddy field. The water quality detection and sampling device comprises a water quality sampling barrel, wherein a plurality of separation plates are arranged in the water quality sampling barrel; side edges of the separation plates are fixedly connected with an inner side wall of the water quality sampling barrel in a sealing manner; the separation plates are used for dividing the inner part of the water quality sampling barrel into a plurality of water quality sampling rooms; waterdischarging end openings are formed in side walls of the bottoms of the water quality sampling rooms; side edge of water blocking plates are connected with inner side walls of water inlet channels ina manner of sliding leftward and rightward; stopping rings are arranged at the right sides of the blocking plates; the left end faces of the blocking plates are fixedly connected with pushing and pressing rods which penetrate through the water inlet channels; baffle plates are arranged at penetrating-out ends of the pushing and pressing rods; the baffle plates are connected with the side walls ofthe water inlet channels through pressure springs; the elastic coefficients of the pressure springs in the water quality sampling rooms are gradually increased from top to bottom. The device is simple in structure and water quality with different depths can be automatically sampled, without the need of operation; the device is convenient to operate, can be used for sampling the water quality andslurry at the same time so as to improve the detection comprehensiveness and has relatively strong practicability.

The invention discloses a polyculture enrichment screening method for ocean heterotrophic denitrifying bacteria. With the method, the ocean heterotrophic denitrifying bacteria can be enriched in an early-stage autotrophic mode and a later-stage heterotrophic mode, and the bacteria with heterotrophic nitrification capability and heterotrophic nitrification and aerobic denitrification capability can be guaranteed to propagate. The polyculture enrichment screening method comprises the following steps: firstly, separating a selective culture medium; then, detecting and separating the ammonia monooxygenase gene and the nitrite oxidoreductase gene of a bacterial strain; finally, in a heterotrophic culture medium, determining whether a bacterial strain with a target gene is expressed or not by a nitrogen balance test. The autotrophic mode and the heterotrophic mode are alternately used for domestication and, enrichment as well as separation to finally obtain the screened bacterial strain which is determined as the heterotrophic nitrification bacterial strain or the heterotrophic nitrification and aerobic denitrification bacterial strain. The polyculture enrichment of heterotrophic nitrification and aerobic denitrification bacteria is not only the breakthrough of the bacteria enrichment theory, the bacterial strain is immobilized with a biofortification method to have a great practical application meaning for the biological denitrification of ocean cycling breeding wastewater, and the method is suitable for treating wastewater in the nitrification unit for the factory high-density breeding.

The invention discloses a pond fish culturing technology. A method includes the following steps that a pond is cleaned, water is discharged, after the pond is cleaned, the pond is exposed to the sun till the bottom of the pond cracks, quicklime is used for disinfecting the bottom of the pond, the water discharging depth is 1.3 m, high-quality fry are selected for well completing the inspection and quarantine work in the fry throwing process, according to the throwing density and proportion of the fry, 400 grass carps are thrown per mu, each grass carp weighs 50-150 g, 10 silver carps are thrown per mu, each silver carp weighs 50-250 g, 300 golden carps are thrown per mu, each golden carp weighs 50-100 g, 100 common carps are thrown per mu, and each common carp weighs 50-100 g, water quality and water level control is conducted in daily management, fodder is used for feeding, taking the grass carps and the silver carps as an example, ryegrass is taken as the main fodder for the grass carps and the silver carps, disease prevention is conducted, powder chlorine dioxide is used for disinfecting and sterilizing, three times of insect killing is appropriate all the year round, trichlorfon and copper sulfate are generally used for insect killing, and catching and stocking are conducted in rotation. According to the method, the yield and the quality of polyculture fishes can be effectively improved, the diseases are reduced, and the culture benefits are improved.

The present invention provides compound feed for the polyculture of Litopenaeus vannamei and Trachinotus ovatus and a preparation method thereof. The compound feed is characterized by comprising the following ingredients in parts by weight: 15-25 parts of fish meal, 5-10 parts of meat and bone meal, 1-5 parts of maggot powder, 15-25 parts of soybean meal, 5-10 parts of peanut bran, 1-5 parts of soybean protein concentrate, 1-5 parts of cottonseed meal, 1-5 parts of corn gluten meal, 1-3 parts of molasses yeast, 1-3 parts of corn DDGS, 1-3 parts of squid paste, 1-3 parts of shrimp shell powder, 20-25 parts of high-gluten flour, 1-2 parts of sea fish oil, 1-2 parts of soybean oil, 1-2 parts of soy lecithin, 0.5-1 parts of calcium dihydrogen phosphate, 0.1-0.3 parts of choline chloride, 0.1-0.3 parts of cholesterol, 0.05-0.1 parts of L-ascorbate-2-monophosphate, 0.1-0.3 parts of coated lysine, 0.1-0.3 parts of coated methionine, 0.1-0.3 parts of Bacillus subtilis, 0.1-0.3 parts of mannan, 0.1-0.5 parts of complex vitamins, 0.1-0.5 parts of complex mineral salts. Experiments show that the compound feed for the polyculture of Litopenaeus vannamei and Trachinotus ovatus of the present invention can effectively meet the comprehensive nutrient needs of both Litopenaeus vannamei and Trachinotus ovatus, significantly improves the effective utilization of the feed, and has a relatively low food coefficient.

The invention relates to an ecological healthy culture method of Palaemon carinicauda. The ecological healthy culture method of Palaemon carinicauda includes firstly, selecting a pond; secondly, pretreating the pond; thirdly, feeding water; fourthly, medially inspecting and putting in parent shrimps; fifthly, controlling water quality; sixthly, performing polyculture of fishes; seventhly, putting in feed; and eighthly, performing culture management. The ecological healthy culture method of Palaemon carinicauda is simple in process and low cost. Water pollution caused by excess feed residue or excrement in the culture process of Palaemon carinicauda is reduced. Medicine residue in aquatics and waters due to massively using fishery medicines to prevent and control fish diseases is reduced. The ecological healthy culture method of Palaemon carinicauda is widely applicable.

The invention discloses a finless eel pond-net cage ecological culture method, and belongs to the technical field of aquaculture. The method includes the steps of (1) finless eel pond-net cage ecological system construction including A, pond preparation, B, net cage arrangement, C in-cage ecological treatment and D, pond ecological treatment; (2) finless eel breeding; (3) food habit domestication and bait feeding; (4) daily management; (5) finless eel catching. Compared with the prior art, the method has the advantages that a pond-net cage ecological system is successfully constructed by utilizing biological characteristics and feeding habits of several kinds of cultured fishes, net cages need not to be scrubbed frequently, and manual labor force is saved; frequent water transfer is not required, culture expenditure is saved; the finless eel are low in morbidity, less in drug use, high in survival rate, high in quality and good in taste; meanwhile, considerable profit is obtained from polyculture fishes.

The invention relates to the technical field of crop planting and aquaculture, in particular to a breeding method of crawfish polyculture in a lotus root field. The method comprises the four steps of farmland work of lotus root field construction, selection of cultivation and breeding time, cultivation management of lotus roots and breeding management of crawfish. According to the breeding method, water body space of a lotus root field piece is sufficiently used for culturing crawfish, firstly, aquatic plants and biological baits in the lotus root field can be used as natural feed of the crawfish, the biological weeding effect of the lotus root field is achieved, and the use ratio of the lotus root field is improved; secondly, excrement of the crawfish can further provide organic fertilizer for the lotus root field, virtuous cycle is achieved, and therefore the method has wide application prospects in the technical field of crop planting and aquaculture and is suitable for industrialization large-scale development and usage.

The invention discloses a selenium-rich compound hard pellet feed for polyculture fishes. The raw materials of the feed comprises a selenium-rich fermented raw material, red fish meal, spray-dried animal blood cells, cottonseed protein powder, flour, wheat, rapeseed meal, rice bran, a mineral premixture, monocalcium phosphate, fish oil, calcium propionate and oligosaccharide which are prepared into a feed base material by weight parts, and the feed base material is conditioned and cured by using a double-shaft differential conditioner under the conditions of certain steam pressure, humidity and temperature. The feed has the advantages of high utilization ratio, high resistance to trophic factor damages, high stability in water and small feed coefficient. When the feed is used for breeding polyculture fishes, water pollution can be reduced, the survival rate of the polyculture fishes can be improved, and the breeding cost can be reduced; and moreover, bred fishes have the advantages of good body shapes, delicious meat and abundant organic selenium content, and free radicals in the human bodies can be cleared away by eating the bred fishes, so that the selenium-rich compound hard pellet feed has a health-care effect on the health of the human bodies.