205 results about "Juvenile fish" patented technology

The invention relates to the technical field of water conservancy project fish protection, in particular to a safe and efficient fish descending device and a descending operation method.The safe and efficient fish descending device comprises a descending tower, a descending fishway is arranged on the descending tower, and the descending tower communicates with an upstream river channel and a downstream river channel through a fish luring pond and a buffering fishway; an upstream dispatching area controlled by a gate is arranged on the upstream and used for attracting juvenile fishes and sending the juvenile fishes into a downstream fishway; the spiral descending fishway is arranged, the occupied area needed by a fish descending channel is greatly reduced, and the spiral descending fishway is suitable for various intermountain high dam environments lacking of construction of the descending channel; meanwhile, by arranging the buffer pool and the buffer fishway, the impact on the fishes during descending can be greatly relieved, and the survival rate of the fishes is increased; after the juvenile fishes are attracted into the fish luring pond through the fish luring mechanism, the juvenile fishes can be quickly conveyed to the downstream river channel through the downstream fishway by using the upstream and downstream water head difference as power, the downstream efficiency is high while the maintenance cost is kept low, and the device is suitable for wide application and popularization.

The utility model discloses a demersal roe hatching device, which relates to the technical field of roe hatching and comprises a hatching container, a hatching sieve bed, a weeping pipe and an overflow pipe, the overflow pipe and the hatching sieve bed are arranged in the hatching container, the top of the hatching container is open, the weeping pipe is arranged above the hatching container and communicated with a water inlet pipe, and a sieve is laid in the hatching sieve bed. Meshes of the screen mesh are smaller than the diameter of the fertilized eggs, so that the fertilized eggs can be flatly laid on the screen mesh before incubation, and the incubation screen bed is at least 10cm lower than an overflow port of the overflow pipe. The fertilized eggs can be flatly laid on the screen in the hatching screen bed in the middle layer of the water body, it is guaranteed that each fertilized egg can obtain sufficient dissolved oxygen supply of the water body, the development requirement is met, hatched fries can fall into the bottom of the hatching container from the screen in time, and the hatching efficiency is improved. Dead eggs and egg shells can be effectively prevented from being infected with water mildew to harm development of other normal fertilized eggs, the work intensity of manually picking up the dead eggs in a traditional hatching mode is reduced, and the hatching rate of the fertilized eggs and the survival rate of juvenile fishes are increased.

The invention provides an AI-based trachinotus ovatus juvenile fish culture water parasite prediction and prevention method and system, and the method comprises the steps: collecting multi-source data from a culture water body through a sensor array, including a nucleic acid signal, a fish school behavior track and an environment parameter sequence, and obtaining an original data set; unifying the data format and the acquisition frequency according to the original data set by adopting a time sequence alignment method, and obtaining an aligned feature flow; aiming at the aligned feature flow, applying a convolutional neural network to extract a space-time pattern of a nucleic acid signal and an abnormal index of a fish school behavior, and determining an extracted feature set; if the abnormal index in the extracted feature set exceeds a preset threshold value, a causal association between environmental parameters and parasitic risks is classified through a support vector machine, and a preliminary risk level is judged; simulating a water body change scene according to the comprehensive causal model to obtain a predicted trajectory of parasite propagation; and determining a quantitative score of the parasite risk and generating a prevention and control instruction sequence by comparing the predicted trajectory with the real-time monitoring data.

The invention discloses a Pelteobagrus vachelli population dynamic monitoring system and method, particularly relates to the technical field of fishery resource monitoring, and aims to solve the problems of inaccurate juvenile fish survival rate evaluation and poor monitoring timeliness in a benthic hidden environment in the prior art. The method comprises the following steps: arranging a benthic penetration type sonar array to synchronously collect a water body reflection signal and a benthic environment sample, and extracting juvenile fish specific gene fragments by combining an environment DNA (Deoxyribose Nucleic Acid) enrichment technology to generate concentration distribution data; screening juvenile fish distribution data by using an acoustic reflection signal and body length correlation model, and positioning an active hot spot area through space-time overlapping analysis; deploying a directional sound wave excitation device to obtain escape trajectory data, and calculating a survival rate in combination with a density attenuation model; finally, multi-source data and topographic features are fused to generate a real-time population dynamic monitoring result, and high-precision and non-intrusive monitoring of the juvenile fish population in the hidden environment is realized.

The invention relates to a method for improving body color and growth of young lutjanus erythropterus, which comprises the following steps of: breeding the young lutjanus erythropterus in an indoor breeding barrel, feeding the young lutjanus erythropterus with feed in the period, feeding the young lutjanus erythropterus once in the morning and afternoon every day, changing water and cleaning the bottom every day, and carrying out breeding under the following conditions: i) continuously aerating in the breeding barrel by using a nano air stone, the concentration of dissolved oxygen is 6.5-7.4 mg / L, ii) the pH value of water in the culture barrel is 7.5-8.4, iii) the water temperature and salinity in the culture barrel are kept relatively unchanged and are 27.3-33.2 DEG C and 25-31 per mill, and iv) the culture barrel is covered with black-out cloth, the illumination condition of culture is set as a blue light source, and the light intensity from the edge to the center of the culture barrel is 250-1500lux; and v) the breeding period is more than 45 days. According to the method, the proper light environment is created for the lutjanus erythropterus according to the preference of lutjanus erythropterus to the light environment, the growth and survival rate of the lutjanus erythropterus can be improved, the brightness and redness value of the lutjanus erythropterus body color can be improved, lutjanus erythropterus seedlings which grow fast, are good in condition and are high in survival are obtained, and the economic benefits of breeding enterprises are improved.

A juvenile fish cultivation apparatus and method, relating to the technical field of aquaculture. The juvenile fish cultivation apparatus comprises a cultivation tank (1), a visual identification apparatus (3), a translation mechanism, and a feeder capable of timed activation. A cultivation pond (2) is provided in the cultivation tank (1); the cultivation pond (2) is divided into three feeding areas by means of partition plates (9); isolation holes (11) and a fish pass gate (10) capable of opening and closing are provided on each partition plate (9); and fish guiding devices (5) are provided in the feeding areas located on both sides. The feeder is translated by means of the translation mechanism; the translation direction is perpendicular to the arrangement direction of the feeding areas; and the feeder can swing reciprocatingly for feeding. The visual identification apparatus (3) comprises a visual module and a control module; when the visual module detects that a juvenile fish in the middle feeding area has grown to a preset large-size, the fish pass gate (10) opens and the fish guiding devices (5) are started; and when there is no juvenile fish in the middle feeding area, the fish pass gate (10) closes and the fish guiding devices (5) are turned off. Regular and dosed feeding can be achieved, inconvenient feeding caused by aggregated bait is avoided, and a safe growth environment with sufficient feed is provided for small-sized juvenile fishes, thereby reducing the size disparity among juvenile fishes.

The invention provides a breeding method of hypoxia-resistant golden tiger hybrid spots, which comprises the following steps: carrying out artificial insemination on a female parent of epinephelus coioides and a male parent of epinephelus coioides to obtain fertilized eggs, carrying out 2.8-3.2 mg / L hypoxia screening on the female parent for more than three generations, and ensuring that the suffocation point is less than or equal to 0.9 mg / L. Performing staged low-oxygen incubation on the fertilized eggs, gradually reducing dissolved oxygen in an embryonic period, a protointestinal period and a membrane emergence period, performing specific sound wave stimulation in an opening period of larva fish, performing low-oxygen-resistant phenotype screening in a larva period, performing intermittent low-oxygen intensive training in a juvenile fish period, applying water flow stimulation before training, and performing low-oxygen-resistant phenotype screening in a membrane emergence period; during the period, a fortified feed containing gamma-aminobutyric acid, heme iron and other components is fed. According to the method, through multi-link collaborative innovation, the hypoxia resistance of the Jinhu hybrid spots is effectively improved, the survival rate of a target group under 2.5 mg / L dissolved oxygen reaches 93%, the suffocation point is reduced to 0.75 mg / L, meanwhile, gill filament development and growth are promoted, and an efficient technical scheme is provided for aquatic product breeding.

The invention provides an automatic bait casting system for training and breeding juvenile plectropomus leopardus, which comprises a basic data module connected with an automatic bait training device and used for acquiring original data of a breeding pond and extracting feeding basic data; the dynamic association module is used for carrying out multi-level cross association modeling, causal inference association, sub-mode mining and classification adaptation to obtain an ingestion-turbidity dynamic association model and outputting an ingestion-turbidity relationship; the hunger index module is used for constructing a hunger index model and outputting the hunger index of each culture pond; the feeding strategy module is used for calculating the next feeding interval, the strip-shaped bait-live bait proportion, the actual time point of next feeding and the bait amount per hour and judging whether extra meal or increase of the next feeding interval is needed or not to obtain a self-adaptive feeding strategy; and the feeding driving module is used for controlling the running action of the automatic bait training device. Scientific feeding can be achieved, the feeding survival rate, the growth rate and the bait training effect are remarkably improved, feed waste is reduced, and intelligent and automatic management of the whole process is achieved.

The invention relates to a method for evaluating toxicity of spiroxamine by using zebra fish and application of the method, and belongs to the technical field of toxicity detection. According to the method, spiroxamine culture solutions with different concentrations are prepared for culturing zebrafish embryos, embryonic development detection and juvenile fish behavior testing are carried out, embryonic development detection includes hatching rate, heart rate and body length, and juvenile fish behavior testing includes spontaneous movement testing, vortex escape testing, swimming behavior testing, reflex behavior testing and color stimulation testing. According to the method provided by the invention, the toxic effect of spiroxamine on zebra fish embryos and juvenile fishes is systematically and comprehensively evaluated, the intuition and accuracy of spiroxamine toxicity detection are improved, and the method can be applied to evaluating the toxicity of environmental samples containing spiroxamine.

The invention discloses a red fluorescent silicon nanodot as well as a preparation method and application thereof. The method comprises the following steps: S1, weighing sulforhodamine 101, adding ultrapure water for dissolving, then adding N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, uniformly stirring, transferring the obtained mixture into a reaction kettle, and heating for reaction; and S2, after the reaction is finished, cooling to room temperature, purifying the obtained product by using a silica gel chromatographic column, eluting by using an eluent, collecting the eluent, and finally, freeze-drying to obtain the red fluorescent silicon nanodots. Compared with common blue-green fluorescence, red fluorescence emission has deeper tissue penetrability and background fluorescence interference resistance; the silicon nanodot provided by the invention not only has excellent light stability and high quantum yield, but also has characteristics similar to lipophilic cations, and can specifically target mitochondria in living cells; in addition, the silicon nanodots also show excellent imaging ability in zebrafish embryos and juvenile fish bodies.

The invention relates to an application of extracellular beta-glucan derived from aureobasidium melanogenum in preparation of a training immunity inducer. By establishing a mouse bone marrow derived macrophages (BMDMs) and zebra fish juvenile fish training immune activation evaluation model, the immunocompetence of extracellular beta-glucan (eBG) derived from aureobasidium melanogenum is evaluated, and it is found that the extracellular beta-glucan has a more remarkable training immune activation effect compared with beta-glucan (cBG) derived from cell walls, and the immunocompetence of the extracellular beta-glucan (eBG) derived from aureobasidium melanogenum is improved. It is proved that the extracellular beta-glucan (eBG) from the melanin-producing aureobasidium is an excellent training immunity inducer and has a good application prospect in the fields of feed addition of bred animals and disease immune prevention and control.

The invention provides an artificial propagation method of Sinilabeo wuyi, and belongs to the technical field of aquatic animal breeding. The artificial propagation method of the Sinilabeo wuyi comprises the steps of parent fish classification, parent fish rearing, artificial spawning induction, natural insemination, artificial insemination, fertilized egg incubation, fry rearing, juvenile fish rearing and the like. The oxytocic is reasonable in compatibility, the injection time of the oxytocic is accurate, the oxytocic rate, the fertilization rate and the hatching rate are increased, and damage to parent fishes is small. According to the method, feeding methods in different stages of fry breeding are also defined, the survival rate of the sinilabeo wuyi fry breeding stage is increased, and a technical support is laid for artificial breeding of the endangered species sinilabeo wuyi.

The invention discloses a zebra fish spermatogonial stem cell separation and transplantation method, and belongs to the technical field of fish germline stem cell separation. The method comprises the following steps: washing complete sexual glands of zebra fish testis by adopting penicillin / streptomycin double-antibody-containing PBS (Phosphate Buffer Solution), physically shearing, digesting and dissociating, and filtering by a screen, so as to obtain zebra fish testis cell suspension; performing density gradient centrifugation to obtain zebra fish spermatogonial stem cells; dyeing, marking, centrifuging, washing, re-suspending, and carrying out micro-injection transplantation to enter the back of the abdominal cavity of the acceptor zebrafish juvenile fish. According to different physical properties of different cells, spermatogonial stem cells are separated, purified and transplanted from zebra fish testis cell suspension by adopting a density gradient centrifugation method, and migration and proliferation processes of donor germ cells can be observed in receptor fish after fluorescence labeling. And a new technical path is provided for fish germplasm resource preservation, endangered fish protection, economic cultured fish yield increase and new variety cultivation.

The invention discloses a method for efficiently trapping young tilapia mossambica. The method is mainly composed of specially-made baits and an improved ground cage. The bait is prepared from the following components: 20% of silkworm chrysalis meal, 20% of acete chinensis meal, 20% of earthworm powder, 12% of wheat germ powder, 11% of lamellar algae powder, 10% of snowflake powder, 5% of vital gluten and 2% of vanillin. The content of animal-derived protein in the bait is increased, so that strong fishy smell can be quickly diffused after the bait enters water; and the flaky algae powder, the snowflake powder and the wheat germ powder can form a suspended atomization belt around the bait, so that the bait is continuously peeled off, and the fish luring and retaining effects are better. The vanillin is added, so that the bait emits sweet milk fragrance, and surrounding tilapia mossambica can be effectively attracted. The following improvements are made on the ground cage: an anti-escape design is added; a bait bag is hung near the fish inlet; the space of a fish collecting area is expanded, so that the capturing efficiency is improved.

The invention discloses a method for separating and transplanting spermatogonial stem cells of Chinese sturgeons, and belongs to the technical field of separation of germline stem cells of fishes. The separation method comprises the following steps: washing Chinese sturgeon testis tissues with an L-15 culture medium containing penicillin / streptomycin double antibodies, and carrying out physical shearing, digestive enzyme enzymolysis and screen filtration to obtain a Chinese sturgeon testis cell suspension; performing percoll density gradient centrifugation to obtain high-purity spermatogonial stem cells of the Chinese sturgeons; and dyeing, washing, resuspending and carrying out micro-injection transplantation to enter the gonad primordium reproductive ridge part of the juvenile acceptor fish. According to the physical characteristics of the spermatogonial stem cells of the Chinese sturgeons, the spermatogonial stem cells with high purity are obtained by adopting percoll density gradient centrifugation, and the purpose of abdomen borrowing reproduction is achieved by adopting a microinjection mode, so that the preservation of germ cells of endangered fishes and the reconstruction of artificial populations are realized; and a new technical approach is provided for protecting genetic resources of the Chinese sturgeons and breaking through artificial propagation bottlenecks.

The utility model discloses an incubation fish tank with a filtering function, which comprises a tank body, a fish culture area and an incubation area are arranged in the tank body, a separating partition plate is arranged in the incubation area to divide the incubation area into a female fish area and a roe area which are distributed up and down, and a plurality of through holes for roes to pass through are arranged on the separating partition plate. The female fish area and the roe area are communicated with the fish culture area, isolation plates for blocking the female fish area, the fish culture area, the roe area and the fish culture area are detachably arranged in the tank body, after female fishes in the female fish area lay eggs, roes enter the roe area through the through holes to be hatched into juvenile fishes, the isolation plates are taken out after the juvenile fishes reach the length, and the female fishes and the juvenile fishes enter the fish culture area through the channels. Compared with the prior art, the fish hatching device has the advantages that after fish eggs are hatched into small fishes, the small fishes and adult fishes do not need to be separated specially, female fishes and juvenile fishes in the hatching area can enter the fish culture area only by pulling out the isolation plate after the small fishes grow up, and operation is easy and convenient.

The invention provides a full-indoor artificial breeding method for plectropomus leopardus, and belongs to the technical field of artificial breeding of marine fishes. The full-indoor artificial breeding method for the plectropomus leopardus comprises the steps of earlier-stage incubation of fertilized eggs, incubation in an indoor breeding pond, breeding in an indoor flowing water pond, breeding in an indoor circulating water pond and the like. By regulating and controlling illumination, the irritability of the fries is greatly reduced, the ecological conditions of the fries are effectively optimized, and the health condition and adaptability of the fries are improved. Meanwhile, different types and different total amounts of biological bait combinations are fed in the larva stage, the juvenile stage and the fish stage of the plectropomus leopardus, transition is made in each bait transfer period, enteritis caused by excessive intake of larvae and juveniles and too little intake caused by inadaptation of bait transfer are effectively reduced, and the problem that the survival rate is low in the bait transfer period can be effectively solved.

The invention belongs to the technical field of aquatic genetic breeding, and particularly relates to a grass carp disease-resistant character genome breeding method and related application thereof. According to the method, filial generation juvenile fish families produced by non-family grass carp parents from different geographical sources are used for constructing an anti-hemorrhagic disease reference group, the disease-resistant SNP site provided by the invention is used for calculating a genome estimation breeding value of a candidate group, and individuals with high breeding value are relatively high in disease resistance and can be used for breeding disease-resistant improved varieties of grass carp.

The invention discloses a large-size seawater fry factory-like grading cultivation system, and relates to the technical field of aquaculture. The system comprises a first-stage culture pond, a second-stage culture pond and a third-stage culture pond. The first-stage culture pond is connected with the second-stage culture pond through a conveying pipeline, and the second-stage culture pond is arranged in the third-stage pond. The first-stage tank is provided with an independent first circulating water filtering device and a monitoring unit, and the second-stage tank and the third-stage tank share a second circulating water filtering and monitoring unit. Each monitoring unit integrates growth detection, environment regulation and control and disease early warning functions. The first-stage pond is used for cultivating newly hatched larvae, and the larvae are automatically transferred to the second-stage pond through a conveying pipeline when developing to a juvenile fish stage; the second-stage pond and the third-stage pond jointly form a polyculture environment, and when the juvenile fish reaches the target specification, a cage door is opened, and the juvenile fish is transferred into the third-stage pond. According to the system, through grading environment control and an automatic transfer mechanism, efficient breeding of fish fries from larva fish to large-scale fish fries is achieved, and the problems of uneven growth, low sorting efficiency and the like in traditional fish fry breeding are solved.

This invention discloses a multi-unit composite stress tiered breeding device and method for juvenile large yellow croaker, belonging to the field of aquaculture breeding technology. The device uses a central control unit as its sole core, forming a fully integrated unidirectional closed-loop drive system. Four independent breeding units are connected through a transparent channel with a centrally located aeration head, forming a physical flow-limiting isolation structure. Each unit independently regulates water temperature, salinity, and dissolved oxygen, creating a multi-factor composite stress gradient. The breeding method employs a three-factor linear equal-gradient synergistic progressive setting, utilizing the juvenile fish's autonomous adaptation and avoidance instincts to achieve cross-unit migration and natural selection. Combined with contour recognition and dynamic tracking algorithms, it monitors the fish population status and mortality rate in real time, and identifies superior offspring with comprehensive stress resistance through secondary verification under extreme stress. This invention offers high screening accuracy and automation, increasing the survival rate of superior individuals by over 40%, reducing labor costs by over 60%, and allowing for flexible adjustment of device parameters. It can be extended to the stress resistance breeding of other marine economic fish species.

The present invention discloses a net cage device for aquaculture of sand snakeheads, comprising a net cage, a cone, a sinker, and a rope. The net cage is formed by sewing a bottom mesh sheet and a peripheral mesh sheet, the mesh sheet being provided with a plurality of circular holes, the edges of the circular holes being sewn to the fan-shaped mesh sheet to form an embedded cone with a closed top, the sinker being sewn to the periphery of the bottom of the net cage so that the net cage extends into the water body; the rope being passed through the periphery of the top of the net cage, and the tail of the rope being used to secure the net cage. The net cage device of the present invention has a strong and simple structure, a long service life, is suitable for a variety of specifications, has a wide range of uses, is convenient for daily management during aquaculture, is convenient for anytime and quantitative fishing, reduces fishing intensity and fish fishing stress, and improves fishing efficiency; at the same time, it meets the needs of sand snakehead juveniles and adult fish for a hidden habitat, reduces spatial competition of sand snakeheads, increases the level of sand snakeheads' feeding on bait organisms, reduces energy consumption, and promotes growth.

The application belongs to the field of fish development, and particularly relates to a molecular marker for identifying Nibea albiflora sperm-induced Pseudosciaena heteroclita gynogenesis offspring and hybrid offspring, a primer set thereof, a kit and application. The primer set for identifying the molecular marker of the Nibea albiflora sperm-induced Pseudosciaena heteroclita gynogenesis offspring and hybrid offspring comprises primers F and R, the nucleotide sequence of the primer F is shown as SEQ ID NO. 1, and the nucleotide sequence of the primer R is shown as SEQ ID NO. 2. Based on genomic data analysis, the application develops the molecular marker F / R which can effectively identify the Pseudosciaena heteroclita gynogenesis offspring and hybrid offspring in the juvenile stage. The method comprises extracting genomic DNA of parents and offspring, PCR amplification and agarose gel electrophoresis detection, and finally distinguishing the gynogenesis individuals and hybrid individuals by whether the Nibea albiflora parent marker is contained in the electrophoresis band.

The application relates to the technical field of biological medicine, and particularly discloses a fish rhabdovirus recombinant adenovirus vector vaccine and a preparation method and application thereof. The recombinant adenovirus vaccine carrying the M gene of the SCRV virus is prepared by using a replication-defective recombinant adenovirus vector, and the preparation method comprises the following steps: mandarin fish rhabdovirus M gene cloning, construction of a Pshuttle-CMV-ECMV vector with a target gene SCRV-M, obtaining of a SCRV-M recombinant adenovirus plasmid, screening of the SCRV-M recombinant adenovirus, and preparation of the SCRV-M recombinant adenovirus vaccine. The SCRV-M recombinant adenovirus vaccine prepared by the application can be used for immunoprophylaxis of SCRV virus infection in the juvenile fish stage through a soaking mode, the SCRV-M recombinant adenovirus vaccine has passed an animal safety test, and has a wide application prospect in the prevention and control of fish rhabdovirus.

The utility model discloses a novel young fish fry seed gathers and captures device, including the casing, its characterized in that: the casing upper end is equipped with the feeding opening, and the bait filter drum is arranged in the casing, and the buffer board is arranged in the casing, and the inside rotation is connected with the deflector in the casing, and the left and right ends of deflector all are equipped with the connecting shaft, and one end of connecting shaft is equipped with the gear, and the upper end rotation is connected with the threaded rod in the casing, and the outside screw thread connection of threaded rod has the U type rod, and the left and right ends of U type rod all are equipped with the connecting rod, and the lower end of connecting rod is equipped with the rack, and the upper end of casing is equipped with the first limit slip mouth, and the inside sliding connection of first limit slip mouth has the filter baffle. The utility model can gather and catch the young fish fry of the elastic coating fish, not only can save manpower, can improve the gathering and catching effect, and can also reduce the harm to the young fish fry when gathering and catching.

The invention discloses a method and a system for predicting the concentration of an artificial sweetener acesulfame potassium in offshore culture seawater based on behavior characteristics of juvenile black sea bream. The method comprises the following steps: collecting motion video data of the juvenile black sea bream in different acesulfame potassium concentration environments and preprocessing the motion video data; training based on an improved YOLOv8 network model to obtain a juvenile fish behavior recognition model and a behavior track data set corresponding to the black sea bream juvenile fish movement video data set; and constructing an initial space-time association network model based on GNN and GRU networks, training the initial space-time association network model by using the behavior trajectory data set, and predicting the acesulfame concentration by analyzing the behavior trajectory of the black sea bream juvenile fish to obtain a completely trained space-time association network model. According to the method, the concentration of the acesulfame potassium serving as an artificial sweetener in the environment where the juvenile black sea bream is located can be predicted according to the behavior characteristics of the juvenile black sea bream, and powerful support can be provided for monitoring and early warning of the offshore culture seawater environment.

The invention discloses a lake ecology appropriate water level determination method based on juvenile fish migration and adult fish fattening, and relates to the field of water ecology and water conservancy projects. The method comprises the following steps: acquiring lake basic data; establishing a two-dimensional hydrodynamic model, and simulating a hydrodynamic field in key periods of migration of juvenile fishes and fattening of adult fishes of the target fishes; constructing a habitat model, and calculating a habitat suitability index HSI and a weighted available area WUA; constructing a water level-WUA response curve and performing segmentation fitting; identifying a WUA stable high-value platform through a first-order derivative threshold value, and determining a suitable water level interval; and establishing scheduling mapping between the appropriate water level and the upstream discharged flow. According to the method, water level-habitat quantitative association is realized according to the staging habitat requirements of four major Chinese carps in the Yangtze River, an operable scheduling threshold value is output, the problems that a traditional method is not staging, the index is single and the method is disjointed with engineering are solved, and the method is suitable for ecological scheduling and management of riverway-communicated lakes.

Provided are a larval-fish feed with which it is possible to promote growth by improving the survival rate of larval fish, and a method for rearing fish. A larval-fish feed (40) comprises a body portion (10) configured from a fish-derived-component-containing formulation, and a gel-like coating portion (20) covering the body portion (10). This method for rearing fish includes a first step for feeding a biological bait to a larval fish, and a second step for feeding a larval-fish feed (40) to the larval fish, the second step being started after the start of the first step.

The invention discloses a method for improving the survival rate of yellow catfish transportation, comprising the steps of: (1) selecting healthy yellow catfish fry to be put into aquaculture water tank, water filling in the water tank, then adding composite polysaccharide nanoparticles and composite probiotics, and the yellow catfish fry is temporarily kept in the tank for 1 3 days without food; (2) the yellow catfish fry temporarily kept without food by water and step (1) are packed in aquatic product special oxygen bag, immediately oxygenating and sealing and ensuring that oxygen content is 6 7mg / L, and the bag is put into the carton of inner foam for transportation; the composite polysaccharide nanoparticles include chitosan, astragalus polysaccharide, oligoxylose, roxburghii polysaccharide and wolfberry polysaccharide and are made. The composite polysaccharide nanoparticles of the present invention are conducive to the absorption of polysaccharide and act on tissue, increase water solubility, dispersibility, and the absorption of fish body thereto, effectively avoid the side effect of polysaccharide accumulation and pollute water body, reduce the time and economic cost added to the feed, thus realize the relief of the fish stress under transportation stress.

This invention relates to the field of aquatic compound feed technology, specifically to a special feed for mullet, silver carp, and golden carp cultured in saline-alkali land in Northwest China. The feed is characterized by being composed of the following raw materials by weight percentage: 10%–14% alfalfa meal, 16%–22% soybean meal, 16%–22% corn meal, 5%–7% molasses, 1%–3% yeast powder, 2%–5% lactic acid bacteria preparation, 2%–5% premixed feed for aquatic life in saline-alkali land in Northwest China, 1%–4% fish oil, and 1%–5% vegetable oil. This invention solves the problems of low survival rate, high feed conversion ratio, easy antagonistic inactivation of probiotics, fish oil oxidation, poor water resistance of pellets, and insufficient regional adaptability of traditional feeds. Compared with commercially available ordinary marine fish feeds, the survival rate of juvenile fish is increased by 15% to 30%, the feed conversion ratio is reduced by 10% to 20%, the Vibrio inhibition rate is ≥80%, the power consumption per ton of feed is reduced by 25% to 35%, and the raw material cost is reduced by 30% to 45%. It is suitable for large-scale aquaculture in saline-alkali land in Northwest China and has important value for improving the quality and efficiency of fisheries, ecological restoration, and rural revitalization.

The application discloses a method for rapidly culturing trichodinid, and belongs to the field of aquatic biological technology. Trichodinid widely parasitizes on the body surface of many marine and freshwater economic fishes, is one of main parasitic pathogenic agents of the cultured fishes, is easily transmitted by indirect contact between hosts, causes large-scale death of fry, and brings huge economic losses to fish culture industry. However, trichodinid cannot be cultured in vitro, and its natural infection has seasonal regularity, so that the acquisition of experimental materials of trichodinid has great limitations, the research on trichodinid has been less, and the development of trichodinid disease prevention and treatment drugs and vaccines is hindered. The application achieves the effect that the trichodinid parasitizing on the body surface of the young fish with a certain initial trichodinid infection amount is massively reproduced in a short time by injecting an immunosuppressive agent into the young fish. The method is simple in operation, can significantly shorten the experimental period of trichodinid related research, and is beneficial to the development of drugs and vaccines for preventing and treating trichodinid disease.