79 results about "Rotifer" patented technology

The invention particularly relates to a method for cultivating biological bait in an outdoor pond. According to the method, after an outdoor pond is disinfected and cleaned, a biological fertilizer source and various beneficial bacteria combination are used in a combined mode, cryptococcus ovale, composite diatom and chlorella are inoculated, a stable pond bacterium-algae system is constructed, and various cultivated microalgae are used for strengthening zooplanktons of rotifers, cladocerans and copepods in the bait pond. The breeding period of the biological bait is shortened, the survival rate of the biological bait is increased, the yield of the biological bait is increased, meanwhile, the nutritional value of the biological bait is enhanced, and opening breeding of the fry is facilitated. The breeding method is low in cost and suitable for various weathers, and sufficient bait guarantee is provided for large-scale breeding of fish fries.

The invention provides an in-situ ecological treatment method for recycling prawn culture tail water and application of the in-situ ecological treatment method, and belongs to the technical field of aquaculture wastewater treatment. After the miscellaneous shrimps in the culture water body are cleaned, quick lime is splashed to be matched with an iron chain to drag the bottom, and then a composite treating agent is put; inoculating rotifer, and then supplementing mineral substances; performing water quality verification; the composite treatment agent comprises EM bacteria, a seawater chlorella stock solution and a carbon source. According to the method, in-situ ecological treatment of prawn culture tail water and a zero-drainage culture mode are achieved, the treatment period is short, the culture survival rate is high, new treatment facilities are not needed, and beneficial bacterial algal phases and nutrient elements can be reserved.

The invention provides a low-temperature-resistant trachinotus ovatus fry breeding method which comprises the following steps: (1) parent selection and breeding: taking trachinotus ovatus as a female parent, and carrying out intensive culture before insemination; then low-temperature stress culture is carried out under the condition of 18-20 DEG C, and the survival and normal ingestion parent fishes are used for the subsequent breeding step; (2) cross breeding: screening out sexually mature parents for induced spawning to complete artificial insemination; when the larvae are hatched out of membranes, the larvae are transferred into a breeding pond for fry breeding; (3) feeding rotifer and copepod larvae to the newly hatched larvae; when the larvae are transformed into juvenile fishes, feed containing drosera burmannii is fed, and when the juvenile fishes are transformed into juvenile fishes, feed containing eucommia ulmoides vines is fed for at least 15 days. According to the method, the low-temperature resistance of the trachinotus ovatus fries is effectively improved, and the method is easy to operate, low in cost and easy to apply and popularize.

The invention provides an artificial seedling method of a tiger-dragon hybrid spot, and relates to the field of aquaculture. An artificial seedling method of a tiger-dragon hybrid spot comprises the following steps: (1) selecting an outdoor high-level pond, selecting tiger-dragon hybrid spot fry over 7 days old, and putting the tiger-dragon hybrid spot fry into the high-level pond; (2) feeding rotifers from 7 days to 14 days old, and inoculating protein nucleus Chlorella liquid and halogenated Dunaliella liquid in the pond at the same time; feeding Artemia and Mongolian monilopsis from 15 days to 30 days old; feeding Mongolian monilopsis and yellow mealworm from 31 days to 50 days old; (3) when encountering a rainstorm, feeding a nutrient within 24 hours after the rain. The invention has a high survival rate of seedlings, a large size of the obtained fry, a good seedling effect, and a low mutation rate, and better guarantees the seedling quality of the tiger-dragon hybrid spot. The obtained tiger-dragon hybrid spot fry has stronger resistance, and the subsequent breeding can better cope with the adverse weather effects, which can effectively reduce the breeding risk of the tiger-dragon hybrid spot and significantly improve the breeding efficiency of the tiger-dragon hybrid spot.

The invention discloses a method for culturing seawater rotifers by using prawn shell leavening, which comprises the following steps: S1, cleaning prawn shells to obtain a fermentation substrate; s2, dynamically optimizing fermentation conditions by adopting a multi-agent collaborative reinforcement learning algorithm; s3, predicting the optimal completion time of fermentation by adopting a mixed graph convolutional neural network and an adaptive genetic algorithm, and providing dilution suggestions through a spectral analysis technology; s4, dynamically calculating the dilution ratio, and mixing the fermentation liquor with seawater; s5, pouring the diluent into a rotifer culture pond, predicting the health state of the rotifer by adopting a Vision Transform model, and automatically adjusting a nutrition formula or environmental conditions; s6, monitoring the density of the rotifers in real time through a YOLOv5 target detection model and a camera, and keeping the rotifers within a preset density range; and S7, performing intelligent management on waste treatment based on a multi-objective evolutionary algorithm of non-dominated sorting. According to the method, a multi-agent collaborative algorithm and a deep learning technology are adopted, and intelligent culture of seawater rotifers and optimized treatment of wastes are realized.

The invention provides an aquatic bait biological feed as well as a preparation method and application thereof. Wherein the aquatic bait biological feed comprises a yeast raw material, amino acid raw powder and feed-grade fish oil; wherein the yeast raw material is selected from at least one of yeast metabolite, yeast powder, yeast hydrolysate or yeast cell wall dry powder. The components in the aquatic bait biological feed are appropriate in particle size, can be directly ingested and absorbed by zooplanktons such as rotifers and cladocerans, are easily digested and absorbed by the zooplanktons, and are beneficial to growth and reproduction of bait organisms. In addition, the feed raw materials do not have the problems of pathogenic bacteria and drug residues, and do not have toxicity to bait organisms.

The invention relates to the technical field of aquaculture, in particular to a preparation method and application of seawater larval fish biological bait. The preparation method comprises the following steps: mixing schizochytrium limacinum powder, bile acid and sunflower phospholipid according to a mass ratio of 50: (10-20): (10-20) to obtain the nutrition enhancer; diluting the nutrition enhancer until the concentration is 40g / t-50g / t, so as to obtain a diluent; adding 130-150 common rotifers into each milliliter of diluent, culturing for 12-18 hours, and collecting strengthened rotifers; 30-50 common artemia is added into each milliliter of the diluent, culturing is carried out for 12-18 hours, and reinforced artemia is collected; the combination of the strengthened rotifer and the strengthened artemia is the larval fish biological bait. The larval fish biological bait prepared by the invention is uniform in fry specification and high in survival rate in a bait transfer period, and has remarkable economic and ecological benefits.

The invention discloses an indoor detoxification seedling raising method for plectropomus leopardus, and relates to the technical field of biology. The seedling raising method comprises the steps that after an indoor seedling raising pond is sterilized and killed, newly hatched seedlings of plectropomus leopardus are put into the indoor seedling raising pond, and after the newly hatched seedlings open to eat food, different sterilized and killed baits are adopted for feeding the seedlings in a stepped mode for seedling raising culture. According to the method, multiple baits such as nannochloropsis oculata, oyster larvae, SS rotifers, S rotifers, L rotifers, fairy shrimp nauplius larvae, copepod nauplius larvae, copepod middle worms, fairy shrimp adults and copepod adults are fed in a stepped mode, rapid growth of the plectropomus leopardus juvenile fish is promoted, the disease resistance of the juvenile fish is effectively improved, the environment adaptability is enhanced, and the survival rate of the plectropomus leopardus is increased. And the survival rate is well improved.

The invention provides an artificial breeding method for echinacea chlamydoides. The artificial breeding method comprises the following steps: S1, selecting parent fish; s2, performing nutrient enrichment culture on the parent fish; s3, artificial spawning and fertilization; s4, artificial incubation; s5, seedling cultivation. The feed is reasonably matched to promote parent fish development and improve egg laying and sperm production quality, spawning hormone is manually injected, injection dosage is strictly controlled, eggs and sperm which are well developed are obtained, hatching conditions of the fertilized eggs are controlled, the hatching rate of the fertilized eggs reaches 90% or above, and the hatching rate of the fertilized eggs reaches 90% or above. According to the method, oyster fertilized eggs, rotifers, artemia or cladocerans / copepods nauplii, cladocerans / copepods and floating type larva fry breeding seawater fish compound feed are sequentially fed in the fry breeding period, palatable bait series of different fry breeding stages are established, and a mature fry breeding technical route is formed.

The invention discloses bacillus velezensis Bve1910, which is preserved in the China Center for Type Culture Collection (CCTCC) and has the preservation number of CCTCC NO. M 20221965. The strain and metabolites thereof have strong antagonistic effects on more than ten types of marine culture animal pathogenic bacteria such as vibrio harveyi, vibrio erwiniae, vibrio canbayi, vibrio parahaemolyticus, vibrio alginolyticus, vibrio anguillarum, vibrio cholerae, vibrio shewanii, vibrio rotifer, pseudoalteromonas and photobacterium damarae, are strong in antibacterial activity and wide in antibacterial spectrum, and can be used for preparing marine culture animal pathogenic bacteria. According to the preparation method, the traditional Chinese medicine composition is simple in preparation method and rich and stable in metabolite, an ammonium sulfate precipitation extract, a hydrochloric acid precipitation methanol extraction extract, an ethyl acetate extraction extract and a chloroform extraction extract all have a broad-spectrum bacteriostatic effect, functional substances playing the broad-spectrum antagonistic bacteriostatic effect are compounded and diversified, and the directional selection effect on bacteria in the environment and ecology is not generated; and pathogenic bacteria are not easy to generate tolerance, so that the method has good application safety and ecological safety properties.

The invention provides a biological bait culture method for pond culture water. The biological bait culture method comprises the following steps: S1, building a three-dimensional culture system; s2, preparing an ecological base and a biocenosis; according to the method, by building a three-dimensional cultivation system of the bottom layer modular net cage, the water surface floating type three-dimensional cultivation frame and the intelligent regulation and control system and combining scientific configuration of ecological bases and biocenosis, the problem that bait supply is unstable in traditional cultivation is effectively solved; the light organism cultivation unit, the plant planting unit and the biological membrane carrier unit of the water surface floating type three-dimensional cultivation frame work in a layered mode, bait organisms such as chlorella, copepods and rotifers in different water layers are cultivated in a directional mode, a complete closed-loop food chain is constructed in addition to food filtering and nutrition supplementing of snails and freshwater mussels, and the bait yield per unit water body is greatly increased.

The invention provides a method for culturing Pseudosciaena crocea fries of the Halitium family through multi-stage dynamic bait density regulation and control, and belongs to the technical field of aquaculture. The culture method comprises the following steps: feeding 5-10 rotifers per mL at the age of 0-6 days; feeding 3-5 copepoda nauplii / mL and 0.5-1 artemia newly hatched larvae / mL at the age of 7-15 days; feeding 2-4 artemia nauplii / mL and 10-40% of compound feed at the age of 16-25 days, and gradually increasing the input proportion of the compound feed along with the age of days; 10%-80% of artemia and 20%-90% of compound feed are fed at the age of 26-35 days, and the input proportion of the compound feed is gradually increased along with the age of days; feeding mixed feed for 36-45 days old; photosynthetic bacteria and bacillus subtilis are put into the water body in the whole culture process. Through precise feeding and dynamic regulation and control, the survival rate, growth uniformity and feeding efficiency of the fries of the Pseudosciaena crocea of the sal family are effectively improved, and the quality of the fries is remarkably optimized.

The utility model relates to the technical field of rotifer harvesting device, specifically is a kind of rotifer screening device, it includes air pump and filter basket, the filter basket be equipped with screen, the outside of filter basket is fixed with the float pipe for suspending support filter basket in water body, the top surface of filter basket is fixedly connected with water outlet elbow, the upper end of water outlet elbow extends to filter basket, the lower end of water outlet elbow extends to the lower end of filter basket outside, and air pipe connector is arranged on water outlet elbow, and the lower end of water outlet elbow is connected with the suction pipe that extends into water body, and air stone is hung in suction pipe by inflation pipe, the top end of inflation pipe is connected with air pipe connector, the bottom end of inflation pipe is connected with air stone, and air pipe connector is connected with air pump by gas transmission pipe.The rotifer screening device can automatically screen the required size of rotifer, is easy to operate, and reduces labor intensity.

This invention relates to a method for the targeted cultivation of live feed to enhance the stress resistance of grouper fry, specifically a method for the targeted cultivation of grouper fry and its live feed. The live feed includes artichoke culture and rotifer culture. The targeted cultivation of the artichoke culture includes the following steps: placing artichokes in seawater, adding *Cryptospira spp.* powder, *Spirulina* powder, arginine, and *Cinnamomum camphora* oil for cultivation to obtain the artichoke culture; the targeted cultivation of the rotifer culture includes the following steps: placing rotifers in seawater, adding *Nyctaginus* pink bacteria. Natrialba pink Rotifer cultures were obtained by cultivating bacterial powder, spirulina powder, methionine, and sunflower oil. This method, through targeted cultivation of live feed, enriches the live feed with corresponding functional components. After feeding it to newly hatched juvenile scorpion, it can significantly improve the stress resistance of the juveniles and increase their survival rate, thus solving the industry pain points of slow development, low survival rate, and poor stress resistance of newly hatched scorpion scorpion.

The present application relates to the field of microbial technology and discloses a yeast strain Pichia kudriavzevii and its application as well as a method for cultivating rotifers. The yeast strain Pichia kudriavzevii described in the present application is deposited with GDMCC No: 66038 and its Latin name is Pichia Kudryavzevii . The present application screened out a strain of Pichia kudriavzi from a seawater environment, which naturally has the ability to adapt to the high salinity of seawater, avoiding the problem that Bacillus subtilis and other conventional yeasts in the current freshwater environment cannot be used efficiently in rotifer culture and cause water pollution; at the same time, it has extremely significant culture efficiency when used as bait for rotifers, and can significantly increase the yield of rotifers in a shorter time than conventional Bacillus subtilis and other yeasts, so that rotifer culture can be carried out in a low-cost, high-efficiency, and green and environmentally friendly manner.

The invention provides a culture device and method for carnivorous cyst rotifer, and belongs to the technical field of rotifer culture equipment.The culture device and method for the carnivorous cyst rotifer comprise a culture bin, an isolation mechanism is arranged on one side of the culture bin, and a cleaning mechanism is arranged on the other side of the culture bin; a culture mechanism is arranged at the top of the culture bin; compared with the prior art, the device has the following beneficial effects that by arranging the main partition plate, when food residues and rotifer excrement in the culture bin need to be cleaned, the food residues in the culture bin can be naturally precipitated to the bottom of the culture bin by opening the main partition plate; the rotifers at the top of the culture bin are separated from excrement precipitated at the bottom of the culture bin through the isolation mechanism, the rotifers can be cleaned without being fished out, and the influence of the external environment on the rotifers is reduced.

The application discloses a kind of active sludge water quality state identification method based on rotifer population breeding, it is related to sewage treatment technical field, the method includes: collecting active sludge sample is placed in the culture device that can simulate aeration tank environment;In monitoring period, microscopic imaging is carried out to sample regularly, and time sequence image sequence is obtained;Time sequence image sequence is input into pre-training ViT model, and the type state, position and identity feature vector of rotifer individual are accurately identified and extracted;Based on feature vector, identity matching and continuous tracking of rotifer individual across time point are realized, and trajectory database containing whole life cycle trajectory is constructed;Based on the trajectory database, multiple characteristic parameters related to population breeding are calculated;These parameters are input into pre-trained water quality state classification model, and corresponding water quality state grade is automatically output.The method improves the accuracy and early warning timeliness of water quality state identification result significantly by fine-grained identification, individual tracking and multi-dimensional feature analysis.

The invention provides a sea bass breeding method which comprises the following steps: parent fish selection and intensive cultivation: selecting 3-5-year-old healthy parent fish, domesticating in a circulating water system with illumination, water temperature and salinity, and feeding intensive feed to promote gonad development; step-by-step spawning induction: injecting the female fish twice, and injecting the male fish once to improve spawning induction synchronism; the semen and the eggs are mixed and activated through ultraviolet irradiation, and the fertilization efficiency is improved; pulse-type water flow hatching: inhibiting water mildew by combining with sound wave oscillation, wherein the hatching rate reaches 85% or above; staged fry breeding: phage-probiotic enhanced rotifers are fed in the fry stage, and microcapsule feed coated with sodium alginate-chitosan is used in the juvenile stage, so that the survival rate and the growth speed of the fry are remarkably increased. The method solves the problems of low fertilization rate, weak seedling disease resistance and the like in traditional breeding through methods of environment simulation, nutrient enrichment, biological prevention and control and the like, and is suitable for large-scale seedling breeding and deep-sea breeding.

The application discloses a disease prevention and multi-nutrition strengthening method for biological bait of blue crab breeding, which is applied to biological bait of the blue crab during the period from the nauplius to the zoea, and technical scheme points include disease prevention and multi-nutrition strengthening of rotifer and disease prevention and multi-nutrition strengthening of brine shrimp nauplius. Through multiple disinfection and multi-nutrition strengthening of the living biological bait, especially the rotifer and the brine shrimp nauplius, diseases of the crab seedlings caused by the biological bait with disease bacteria are prevented, and meanwhile, nutrition substances in the biological bait are specialized according to the growth and development needs of the crab seedlings, so that good growth and development of the crab seedlings are ensured.

The utility model relates to the technical field of freshwater fish breeding, and discloses a reservoir ecological freshwater fish rotifer preying device which comprises a material tank, a lower floating block for providing buoyancy is arranged at the bottom of the material tank, a motor is fixedly installed in the middle of the top side of the material tank, and six sets of discharging openings are formed in the bottom wall of the material tank in an array mode. A feeding assembly used for assisting in feeding rotifers is arranged in the material tank, a triggering assembly used for triggering and starting the feeding assembly is arranged in the middle of the supporting plate, and a photovoltaic panel used for providing power for all the components is arranged on the outer side of the material tank. Fish schools can be attracted to gather through the bionic bait, when the fish schools bite the bait, the guide rod can be driven to move downwards, so that the contacts make contact with one another, then the motor can be started, the gear disc rotates to drive the rotating rod to rotate, and then the spiral discharging rod is driven to rotate in the discharging opening to assist in rotifer throwing; therefore, fish schools can prey conveniently, and waste is avoided.

The invention discloses a rotifer nutrient enrichment culture device, and particularly relates to the technical field of rotifer culture, the rotifer nutrient enrichment culture device comprises a culture pond used for culturing rotifers and algae, a culture assembly is installed on the culture pond, the culture assembly comprises a top plate located above the culture pond, and the top plate is connected with the culture pond through a rotating assembly; a fluorescent lamp and an adjusting mechanism are detachably connected to the bottom end of the top plate, the adjusting mechanism is located on one side of the fluorescent lamp, and a nutrition strengthening assembly is detachably connected to the side, away from the adjusting mechanism, of the bottom end of the top plate. According to the method, rotifers and algae are bred and grown in the culture pond together, the algae can provide high-quality protein nutrition for the rotifers, so that nutrition of the rotifers can be enhanced, meanwhile, a fluorescent lamp is utilized for continuous illumination, algae growth is promoted, sufficient food sources can be provided for the rotifers, and the yield of the rotifers is increased. The yeast is intermittently added, so that the growth of the rotifer can be further promoted, the nutrition of the rotifer can be improved, and the rotifer can provide sufficient nutrition for the pomfret fry.

The utility model relates to the technical field of rotifer harvesting devices, in particular to a rotifer feed harvesting device which comprises a base, the inner wall of the base is fixedly connected with the outer wall of a connecting piece, the outer wall of the bottom end of the connecting piece is fixedly connected with the inner wall of a collecting piece in an inserted mode, and the top of the base movably abuts against the bottom of a draining piece. When the rotifers are collected, the lamp ring is turned on, the lamp ring emits light to attract the rotifers in water to the periphery of the collecting water pump, the collecting valve is turned on, the collecting water pump is started, the collecting water pump sucks water and the rotifers in the water, the sucked water and the rotifers enter the connecting pipe through the output end, and the water and the rotifers enter the connecting pipe. The water and the rotifers in the connecting pipe pass through the collecting bent pipe and are sprayed out through the collecting valve, the sprayed water and the rotifers enter the draining bag through the connecting net, the draining bag separates the water and the rotifers, the rotifers are collected in the draining bag, and convenience is brought to use of people.

The invention discloses a circulating type seedling culture water quality regulation and control method based on weak electric field coupling multi-trophic-level organisms, and belongs to the technical field of seedling culture water quality regulation and control. The method comprises the following steps: putting chlorella with a certain density into a culture water body, culturing for a period of time, inoculating rotifers, and then culturing shellfishes in the culture water body to construct a rotifer-algae-shellfish multi-nutritional-level system; titanium electrode plates are placed at the two ends of the aquaculture water body and matched with a direct-current converter, air stones are laid at the bottom of the aquaculture water body, and a power source is switched on to form a weak electric field in the aquaculture water body; after fish and shellfish are bred and collected, the number of rotifers and chlorella in the breeding water body is adjusted to a certain extent according to the putting value, the rotifer-algae-shellfish multi-nutrition-level system is constructed, the aquaculture seedling breeding water body can achieve self-purification, the sewage treatment cost and the influence on the environment are reduced, and the breeding water body is more environmentally friendly. And the metabolic rate of each nutrition level in the multiple nutrition levels is increased through the weak electric field.

The present application belongs to the field of bioengineering, and particularly relates to a method for controlling pests in an open culture system of microalgae based on light-induced coupling electric inhibition. The main steps are as follows: a light irradiation device and a high-voltage discharge device are arranged on one side of a raceway pond; first, light-induced treatment is performed, and the raceway pond is irradiated at the same time, the irradiated light at the left curve and the right curve is blue light with an intensity of 1500-2000 Lux; the irradiated light at the upper raceway and the lower raceway is red light with an intensity of 1000-2000 Lux; so as to attract rotifers to the left curve and the right curve to form rotifer aggregation areas; then, the rotifer aggregation areas at the left curve and the right curve are subjected to electric shock treatment; the present application can kill rotifers while protecting the survival of algae as much as possible, and can effectively remove most of the pest pollution through the combined regulation of light induction and high-voltage discharge, so as to ensure that the growth of microalgae biomass and the accumulation of bioactive substances are less affected, and the application prospect is wide.

The seawater rotifer cultivation method comprises the steps that at least one supporting layer and at least one sacrificial layer arranged on the supporting layer are constructed, and the sacrificial layer is configured to be modified through changes of external conditions; cultivating a thin film on the sacrificial layer and growing the thin film; changing external conditions to modify the sacrificial layer and obtain an independent film; and cleaning and drying the obtained single film, and grinding and sieving to obtain the copper nitride powder. According to the method, the independent thin film is obtained, grinding and sieving are carried out on the basis of the thin film, so that the copper nitride powder is obtained, and compared with an existing method, the method has the advantages that the heating temperature is small, pressurization is not needed, energy consumption is small, environment friendliness is better achieved, operation is easy and convenient, practicability is high, and the yield is high, and has very high application prospects.

The invention provides a method for preventing and controlling pear ring rot by using tyrosol. The pear ring rot is prevented and controlled by externally spraying a tyrosol aqueous solution. The concentration of the tyrosol in the tyrosol aqueous solution is 1-5 mg / ml. According to the invention, Dangshan pears are taken as experimental materials, and in-vitro bacteriostasis experiments and botryosphaeria dothidea inoculation experiments prove that tyrosol has a remarkable inhibiting effect on pear botryosphaeria dothidea, and can effectively inhibit the development speed of botryosphaeria dothidea scab and reduce the occurrence and spreading of diseases, so that the damage of botryosphaeria dothidea to plants is reduced. Tyrosol is a natural compound in plants, has low toxicity, and can enhance the defense mechanism of pear when applied to prevention and treatment of pear ring rot, improve the natural resistance of pear to ring rot, reduce or replace the use of chemical pesticides, and reduce the potential risk to the environment and human health.

The utility model discloses a high density rotifer counting device relates to petri dish technical field, including the dish body and is used for improving the bearing subassembly of its whole placement stability, the dish body is provided with a plurality of round groove, the bearing subassembly includes the bearing seat, the bearing seat is provided with the bearing groove, the bearing groove is provided with the round groove, and the bearing seat is provided with the round groove. The dish body is placed in the bearing groove, and a suction cup is arranged on the bottom face of the bearing base. The rotifer counting device solves the problems that when an existing rotifer counting device is used for counting the number of rotifers, the existing rotifer counting device is difficult to keep a stable placement state, the rotifer counting device is deviated due to external collision in the working process, and then counting errors are easily caused.

The utility model discloses a circulating type outdoor earth pond rotifer culture device, which relates to the technical field of rotifer culture, and comprises a culture pond, a barrier component is arranged in the culture pond, the barrier component comprises a servo motor, and the servo motor is arranged in the culture pond. The rotifer has phototaxis, the rotifer is attracted to the upper water level, the rotifer is separated from underwater impurities by a certain distance, the gear linearly moves on the rack, the gear drives the connecting rod to rotate, the number net on the connecting rod is unwound and stretched, and the side, away from the connecting rod, of the number net is installed on the inner wall of the culture pond. Therefore, the number net can be well arranged in the middle of water after being stretched, and rotifers can be well separated from impurities at the water bottom. Upper water and rotifers are prevented from being sucked into the drainage pipe and discharged together with the drainage pipe due to too fast drainage operation. And water can be drained more accurately through the blocking assembly.

The invention discloses a factory breeding and facility cultivation method for largemouth bass, and relates to the technical field of largemouth bass cultivation. The specific breeding method comprises the steps of parent fish breeding, fry hatching, fry breeding and adult fish breeding, in the fry breeding step, newly hatched larval bass water spots are bred under the dark condition, pretreated fairy shrimps are adopted as initial feed during breeding, then pretreated fairy shrimp larvae and rotifers are fed, and the young larval bass are bred. The ratio of the rotifers is gradually increased every day until all the rotifers are fed, food conversion domestication is started, 90% of the rotifers and 10% of the fermented artificial compound feed are mixed and fed on the first day after domestication, the proportion of the rotifers is gradually reduced every day, and the proportion of the feed is gradually increased every day until the fries completely adapt to the feed. By means of the fry breeding method, healthy fry which grow neatly and are uniform in size and high in stress resistance can be obtained, and the survival rate and the growth speed of adult fish breeding are increased.

This application relates to the field of rotifer culture technology and discloses a method for regulating rotifer body size. This application successfully controls the body size of marine rotifers by regulating factors such as dissolved oxygen, temperature, salinity, and feed. Specifically, the conditions for large-scale rotifer culture include relatively low dissolved oxygen, temperature, and a larger feed, while the conditions for small-scale rotifer culture include relatively high dissolved oxygen, temperature, and a smaller feed. Certain cyanobacteria can also be used as supplementary feed. This application stably controls the environmental conditions for marine rotifer body size and selectively modifies the feed for the rotifers, achieving the goal of selectively regulating the body size of marine rotifers.