A method for feeding planarians in aquaculture

Abstract

This invention discloses a feeding method for planarian farming. A planarian population calculation formula is established based on planarian life history parameters. A farming formula model for the entire farming cycle is then created by computer programming using the planarian diet and population calculation formula. The planarian diet includes the types of feed provided, and the farming formula model includes a feed amount calculation formula. The farming formula model calculates the feed amount throughout the farming cycle based on the initial planarian population, the initial feed amount, and the number of farming days. By accurately determining the planarian population throughout the entire farming cycle, the feed amount can be calculated more precisely, effectively controlling the survival and reproduction rates of planarians, thus achieving large-scale, optimized planarian farming.

Description

Technical Field

[0001] This invention belongs to the field of protozoan breeding technology, and in particular relates to a feeding method for planarian breeding. Background Technology

[0002] Planarians, representative animals of the phylum Platyhelminthes, are widely distributed in the natural environment. Their regenerative capacity and role in the ecosystem are of significant scientific research value. However, due to environmental pollution, the number of planarians in nature is gradually decreasing, making them increasingly difficult to capture. Artificial planarian breeding is of great importance for the protection of planarian species and the restoration of their ecological value in the natural world. Meanwhile, domestic and international research has found that small planarians, as an important part of the ecosystem, have the ability to prey on some harmful organisms, such as mosquito larvae and isowhoppers, indicating their application value as biological control natural enemies.

[0003] Planarians are carnivorous animals that feed on worms, small crustaceans, and insect larvae under natural conditions. In the early 20th century, scientists began to explore artificial breeding methods for planarians. Currently, they can be fed fresh pig liver, beef liver, fish spleen, or cooked egg yolks. However, these methods have problems such as the feed easily rotting and smelling bad in the water, which seriously affects the water quality of the breeding water. At the same time, the amount of food is difficult to control, making it impossible to achieve large-scale breeding. As a result, it is impossible to release large numbers of planarians into the wild to realize their ecological and application value.

[0004] Intermittent farming is the optimal farming method for many animals. Compared with continuous farming, it has significant advantages in reducing feed waste, improving farming efficiency, and reducing farming costs. Currently, artificial farming methods for small freshwater planarians, such as those using pig liver or egg yolk, all suffer from problems such as overfeeding, which are essentially continuous farming methods. Feeding planarians crushed feed (such as pig liver or egg yolk) can easily cause water pollution, resulting in most of the feed being decomposed by bacteria and other microorganisms. This makes it difficult to assess the actual food source obtained by the planarians. However, the key to intermittent farming lies in how to control the amount of food source to achieve optimal biological farming. At the same time, because planarians are very small and densely packed during the farming process, it is impossible to determine the actual number of planarians using mechanical separation or visual intelligent recognition. Since the number cannot be determined, precise feeding is also impossible. Therefore, the calculation and control of the amount of feed is a critical issue.

[0005] Therefore, those skilled in the art are dedicated to developing a feeding method for planarian farming that can precisely control the amount of feed. Summary of the Invention

[0006] The purpose of this invention is to provide a high-density, large-scale method for raising planarians, in order to solve the problems of difficulty in controlling feed quantity, easy waste, and foul-smelling water in current planarian farming.

[0007] To address the aforementioned problems, this invention provides a feeding method for planarian farming. A planarian quantity calculation formula is established based on planarian life history parameters. A farming formula model for the entire farming cycle of planarians is then established by computer programming using the planarian diet and quantity calculation formula. The planarian diet includes the types of feed provided. The farming formula model includes a feed amount calculation formula. The farming formula model calculates the feed amount throughout the entire farming cycle based on the initial number of planarians, the initial amount of feed, and the number of farming days.

[0008] Furthermore, this includes the following steps:

[0009] S1. Data collection of planarian life history parameters: Ten planarians were placed in petri dishes for culture, and the life history of each planarian was observed under the proposed feed. The following parameters were recorded and averaged. The proposed feed is the feed required for large-scale breeding:

[0010] Planarian lifespan G: The time (in days) from the hatching of the larvae to their death;

[0011] Sexual maturity period D: The time from hatching of larvae to the start of egg-laying (in days);

[0012] Spawning cycle E: Time from the start of spawning to the end of spawning (in days);

[0013] Total number of eggs laid N: The total number of eggs laid during the spawning cycle;

[0014] Egg incubation period F: The time (in days) from when the egg is laid to when it hatches;

[0015] Hatching period f: The time (in days) from the start of incubation of the first egg mass to the end of incubation of the egg mass;

[0016] Number of larvae hatched per egg (n): the average number of larvae hatched from each egg;

[0017] S2. Calculate the following parameters from the above parameters:

[0018] Average daily egg production e: i.e., the average daily egg production during the spawning cycle e = X / E (eggs / day);

[0019] Average daily hatching rate p: that is, the average daily hatching rate of egg masses during the hatching period, p = P / f (%);

[0020] Hatching rate P: The ratio of the total number of hatched eggs to the total number of eggs laid after the hatching cycle ends, i.e., total number of hatched eggs / total number of eggs laid × 100 (%);

[0021] S3. Establish a formula for calculating the number of planarians:

[0022] Let M be the number of planarians in the culture pond on day x. x The number of hatching is mx The number of eggs laid was L x If the initial number of planarians is a constant m0, then x and m x Relationship satisfies:

[0023] When 0 ≤ x ≤ D, the number of eggs laid is L. x The initial number is 0, meaning the planarians hatched in the same batch are inoculated on the first day, i.e., the number of hatched planarians is m1 = m0, while the subsequent number of hatched planarians is m1 = m0. x The number of planarians, M, is 0, assuming no abnormal deaths. x =m0;

[0024] When D < x < (D + F), the number of eggs laid is L. x =e(M x-D =em0, since the egg masses laid by planarians need to go through the incubation period F before they can hatch, the number of hatched eggs is m. x =0, while the number of planarians M x There are two cases: if x > G, then M x =0, otherwise x≤G, then M x =m0;

[0025] When x≥(D+F), the number of eggs laid If the period from the oviposition period of a planarian to the end of its lifespan, i.e., D + E = G, then Take the constant 0, and if x ≤ (D+E) ≤ G, Number of hatches If xF-f+1≤0, then the lower limit of the summation is taken as 1 (when time x is a positive integer, the lower limit is at least 1), and M x =M x-1 +m x -m x-G If xG≤0, then take m. x-G =0 (time x is a positive integer, that is, the minimum lower limit is 1, so when xG≤0, m is defined) x-G =0); The calculation method is shown in the table below:

[0026]

[0027] S4. Assume the type of feed is live nematodes, that is, feed the animal using live nematodes:

[0028] When live nematodes are used for feeding, the feeding amount is determined by the following formula: Feeding amount (mL) = Planarian number M x × Predation coefficient L / Nematode solution concentration K (nematodes / mL), where

[0029] Nematode solution concentration K: The nematode mixture is prepared by filtration and washing of laboratory-cultured nematodes. The nematode solution concentration is calculated as follows: Take 50 μL of the fully concentrated and mixed nematode mixture, observe the number of nematodes under a stereo microscope, repeat 3 times, and then the nematode solution concentration K (nematodes / mL) = total number of nematodes observed in 3 times / 50 μL / 3 × 1000;

[0030] Predation coefficient L: The number of nematodes preyed on by a single planarian every 2 days, which is the average number of nematodes preyed on per day × 2, i.e., nematodes / 2 days.

[0031] Planarian number M x : The number of planarians in the culture pond on day x of culture.

[0032] Furthermore, the live nematodes in step S4 are replaced with strips of pig liver, which are 1 cm long and 0.5 cm in diameter.

[0033] The amount of feed is determined by the following formula: Feed amount (g) = Planarian number M x × Predation coefficient L / weight of strip-shaped pig liver K (strip / g), where

[0034] Calculation of the number of strips of pork liver K: Weigh 1g of the cut strips of pork liver, place them in a petri dish, add water to disperse the pork liver strips, and then count them under a microscope. Repeat 3 times. That is, the number of strips of pork liver K = the sum of the 3 counts / 1g / 3.

[0035] Predation coefficient L: The number of strips of pig liver consumed by a single planarian every 2 days on average, that is, the number of strips of pig liver consumed per day on average × 2, i.e., strips / 2 days;

[0036] Planarian number M x : The number of planarians in the culture pond on day x of culture.

[0037] The beneficial effects of this invention are as follows: The planarian breeding and feeding method of this invention establishes a planarian quantity calculation formula based on planarian life history parameters. A breeding formula model for the entire breeding cycle of planarians is established by computer programming based on the planarian diet and quantity calculation formula. The planarian diet includes the types of feed, and the breeding formula model includes a feed amount calculation formula. The breeding formula model calculates the feed amount throughout the breeding cycle based on the initial number of planarians, the initial amount of feed, and the number of breeding days. Because it achieves accurate judgment of the planarian quantity throughout the entire breeding cycle, the feed amount can be calculated more accurately, effectively controlling the survival and reproduction rates of planarians, and achieving large-scale optimized planarian breeding. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the planarian culture system in this invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any way except for mutually exclusive features and / or steps, and may be replaced by other equivalent or similar alternative features unless specifically stated otherwise, i.e., each feature is merely one embodiment of a series of equivalent or similar features unless specifically stated otherwise.

[0041] In the following embodiments, the planarian culture system for culturing planarians is as follows: Figure 1 As shown, several breeding ponds 1 are provided. All breeding ponds 1 are connected to a nematode breeding tank 2 and a first air pump 3. The nematode breeding tank 2 is connected to a second air pump 4 and a nematode feeder 5. A control valve 6 is provided in the middle of the nematode feeder 5. The second air pump 4 is connected to the nematode breeding tank 2 through a timed control valve 7. Planarians are bred in the breeding pond 1, and nematodes are bred in the nematode breeding tank 2. The first air pump 3 and the second air pump 4 pump oxygen into the breeding pond 1 and the nematode breeding tank 2, respectively. The timed control valve 7 regularly controls the intensity and time of oxygen output by the second air pump 4. The control valve 6 is used to control the amount of feed.

[0042] Example 1

[0043] Taking the culture of mud-dwelling mesoostemma (Dochmiotrema limicola) as an example, the feeding method using small rod-shaped nematodes includes the following steps:

[0044] S1. Data collection of planarian life cycle parameters: Ten planarians were placed in a petri dish for culture. The life cycle of each planarian was observed, and the following parameters were recorded and averaged: lifespan G = 32 days, sexual maturity period D = 9 days, oviposition period E = 22 days, number of eggs laid N = 25.5, egg hatching period F = 7 days, hatching period f = 6 days, number of eggs hatched per egg n = 1, predation coefficient L = 4.5 (planarians / 2 days). Here, the predation coefficient L is the average number of nematodes preyed on by a single planarian every 2 days, that is, the average number of nematodes preyed on per day × 2. Feeding was carried out once every 3 days to ensure that the planarians were in a state of hunger on the 3rd day of the intermittent feeding every 3 days.

[0045] S2. Calculate the following parameters from the above parameters:

[0046] The average number of eggs laid per day during the spawning cycle is e = N / E = 1.2 (e / day);

[0047] The hatching rate P = 72.4%, which means the average daily hatching rate of egg masses during the incubation period is p = P / f = 12.1 (%).

[0048] S3. Establish a formula for calculating the number of planarians:

[0049] Let M be the number of planarians in the culture pond on day x. x The number of hatching is m x The number of eggs laid was L x If the initial number of planarians is a constant m0, then x and m x Relationship satisfies:

[0050] When 0 ≤ x ≤ D, the number of eggs laid is L. x The initial number is 0, meaning the planarians hatched in the same batch are inoculated on the first day, i.e., the number of hatched planarians is m1 = m0, while the subsequent number of hatched planarians is m1 = m0. x The number of planarians, M, is 0, assuming no abnormal deaths. x =m0;

[0051] When D < x < (D + F), the number of eggs laid is L. x =e(M x -D)=em0, since the egg masses laid by planarians need to go through the egg hatching period F before they can hatch, the number of hatched eggs is m. x =0, while the number of planarians M x There are two possibilities: if x > G (planarian lifespan), then M... x =0, otherwise x≤G, then M x =m0;

[0052] When x≥(D+F), the number of eggs laid If the period from the oviposition period of a planarian to the end of its lifespan, i.e., D + E = G, then Take the constant 0, and if x ≤ (D+E) ≤ G, Number of hatches If xF-f+1≤0, then the lower limit of the summation is taken as 1 (when time x is a positive integer, the lower limit is at least 1), and M x =M x-1 +m x -m x-G If xG≤0, then take m. x-G =0 (time x is a positive integer, that is, the minimum lower limit is 1, so when xG≤0, m is defined) x-G =0). The calculation method is shown in the table below:

[0053]

[0054] The specific feeding amount can be derived from the above formula as follows:

[0055] Feeding amount calculation: Before each feeding, record the nematode solution concentration as K (nematodes / mL), that is, feeding amount (mL) = number of planarians M. x ×4.5 / nematode solution concentration K (nematodes / mL), specific values ​​are shown in the table below:

[0056]

[0057]

[0058]

[0059] In step S2, the nematode solution concentration K (nematodes / mL) is determined as follows: a nematode mixture is prepared by concentrating laboratory-cultured nematodes through a filtration and washing method, wherein the filtration and washing method includes the following steps:

[0060] Materials needed: 1 square plastic basin (with lid), 53cm long, 32cm wide, and 10cm high; 1 cylindrical glass container (transparent, without lid), 40cm high, 5cm bottom diameter; 1 rectangular 350-mesh sieve (40cm long, 30cm wide); 1 circular 500-mesh sieve (50cm diameter); 1 plastic basket (30cm long, 20cm wide, 3cm high); 1 plastic tube (50cm long, 2cm diameter).

[0061] Steps: (1) Lay a 350-mesh sieve flat on a plastic basket, and then place the culture medium containing the nematodes that has been cultured in the laboratory on the 350-mesh sieve; (2) Place the plastic basket, nematode culture medium and 350-mesh sieve from step (1) into a square plastic box, add tap water, keep the water level at 3cm, and let it stand for 24 hours; (3) Use a plastic tube to draw the tap water containing the nematodes from the square plastic box into a cylindrical glass container (use a siphon method to draw it all out). After standing for 1 hour at a water level of 30cm, cover the mouth of the cylindrical glass container with a 500-mesh sieve and use a 5mL pipette to insert the middle of the 500-mesh sieve directly into the nematode mixture, and extract the liquid that has been reverse osmoticed from the surface of the 500-mesh sieve; (4) add water of the same volume as the extracted liquid; (5) repeat steps (3) and (4) 3 times to thoroughly clean out the impurities in the nematode mixture; (6) repeat step (3) to concentrate into a high-density nematode mixture.

[0062] Taking the calculation of the daily nematode concentration of 5500 nematodes / mL in the table above as an example, the calculation method is as follows: take 50 μL of the fully concentrated and mixed high-density nematode mixture, observe the number of nematodes under a stereomicroscope, repeat 3 times, and the number of nematodes after the 3 operations are 819, 825 and 831 respectively. Then the nematode solution concentration K (nematodes / mL) = total number of nematodes observed in 3 times / 50 μL / 3 × 1000 = 5500.

[0063] S3. Preparation and Implementation of Relevant Feeding Conditions

[0064] (1) Feed preparation: Take the laboratory-cultured whole-toothed resurrected nematodes, wash them with pure water into a container, remove the water from the nematode solution in the container using a 1000-mesh sieve, and store them in a refrigerator at 4℃ for later use. The storage period should not exceed 20 days.

[0065] (2) Breeding pot: Select a PVC plastic pot (with lid) with a length of 53cm × width of 32.5cm × height of 10cm. Drill a 0.4cm hole in the lid, clean it with detergent, and dry it in an oven at 50℃ for later use.

[0066] (3) Selection of aquaculture water: Use a 5L plastic bucket to collect tap water, place it in a sterilizer at 121℃ for 45 minutes, and then cool it for later use.

[0067] (4) Breeding room: Select a sealable space, install an exhaust fan, turn on the exhaust fan for 8 hours every 3 days to promote air convection between the breeding room and the outside. Control the heater (oil heater, small heater, etc.) through a temperature controller to control the temperature at 26±1℃. Install an industrial thermometer at the entrance of the breeding room to monitor the temperature inside the breeding room.

[0068] (5) Preparation of planarian breeding equipment: In the breeding room, add the breeding water from step (3) to the breeding basin from step (2), and keep the water level in the breeding basin 6cm. Take a 0.4cm hose and connect one end through the 0.4cm hole in the cover of the breeding basin from step (2) to the air stone. Put the air stone below the water level in the breeding basin from step (2), and connect the other end to the air pump. Turn on the air pump to supply oxygen and let it sit for more than 6 hours. Use a water dissolved oxygen meter to measure the dissolved oxygen content in the water. Adjust the air pump to keep the dissolved oxygen content in the water at 10 to 11mg / L. Use an industrial thermometer to measure the water temperature and keep the water temperature at 22±1℃. If the water temperature exceeds the range, the ambient temperature should be adjusted.

[0069] (6) Planarian inoculation: Take 2000 planarian larvae that can prey on nematodes from the same batch of hatched larvae and add them to the culture basin using a 5mL pipette.

[0070] (7) Feeding method: Calculate the number of planarians and the amount of feed given on the day according to step S2. Add the amount of feed given every 2 days (i.e., feed once every 3 days) through the feeding port into the collection box of the feeding device. Pump the nematode solution into the planarian breeding pond through the feeding device. Estimate the amount of feed given according to the number of planarians in the breeding pond. Use a timer to control the feeding device to feed quantitatively, or use a pipette or pipette to achieve this.

[0071] Note: In this example, after 46 days of feeding, the planarian population in the rearing tank was visibly dense. Calculations showed that the number of planarians in the tank exceeded 110,000. The bottom area of ​​the rearing tank was 53cm × [missing information].

[0072] 32.5cm = 1722.5cm 2 The average density is approximately 65 lines / cm². 2 The worms are approximately 2000 μm in length, and their visibly high rearing density was observed. A logistic equation was used to analyze the reproductive model of these planarians in the rearing pond. Under limited conditions, the planarians have limited living space and food sources, while their population approaches the upper limit M. max When the planarian population increases to near zero, i.e., the growth rate k approaches zero, the planarian stocking density is too high, approaching the upper limit of the planarian population in the stocking pond. Therefore, in this example, the planarians were transferred to new stocking ponds after 46 days. In practical applications, the transfer should be done when the planarian population in the stocking pond reaches the upper limit M. max When the number of planarians in the culture pot reaches 80%, the planarians in the culture pot are transferred to a new culture pot to ensure rapid reproduction and avoid food waste.

[0073] Example 2

[0074] Taking the culture of terrestrial planarians collected from Guizhou soil in the laboratory as an example, the nematodes (Rhabditis axei) were used for feeding, including the following steps:

[0075] S1. Data collection of planarian life cycle parameters: Ten planarians were placed in a petri dish for culture. The life cycle of each planarian was observed, and the following parameters were recorded and averaged: lifespan of the planarian G = 25 days, sexual maturity period D = 7 days, oviposition period E = 18 days (the planarian disintegrates and dies directly after laying the last egg), number of eggs laid N = 41.8, egg hatching period F = 4 days, hatching period f = 8 days, number of eggs hatched per day n = 1, predation coefficient L = 5.3 (planarians / 2 days). Here, the predation coefficient L is the average number of nematodes preyed on by a single planarian every 2 days, that is, the average number of nematodes preyed on per day × 2. Feeding was carried out once every 5 days to ensure that the planarians were in a state of starvation on the 5th day of the intermittent feeding every 5 days.

[0076] S2. Calculate the following parameters from the above parameters:

[0077] The average number of eggs laid per day during the spawning cycle is e = N / E = 2.3 (eggs / day);

[0078] The hatching rate P = 60.8%, which means the average daily hatching rate of egg masses during the incubation period is p = P / f = 7.6 (%).

[0079] S3. Establish a formula for calculating the number of planarians: The calculation here is the same as the steps in Example 1, and will not be repeated here.

[0080] S4. Establish a formula for calculating the amount of feed: Record the concentration of the nematode solution as K (nematodes / mL), that is, the amount of feed (mL) = the number of planarians M. x ×5.3 / nematode solution concentration K (nematodes / mL), specific values ​​are shown in Table 3 below:

[0081]

[0082]

[0083] Preparation and implementation of relevant feeding conditions:

[0084] (1) Feed preparation: Take small rod-shaped nematodes cultured in the laboratory, wash them with pure water into a container, remove the water from the nematode solution in the container using a 1000-mesh sieve, and store them in a refrigerator at 4℃ for later use. The storage period should not exceed 20 days.

[0085] (2) Breeding pot: Select a PVC plastic pot (with lid) with a length of 53cm × width of 32.5cm × height of 10cm. Drill a 0.4cm hole in the lid, clean it with detergent, and dry it in an oven at 50℃ for later use.

[0086] (3) Selection of aquaculture water: Use a 5L plastic bucket to collect tap water, place it in a sterilizer at 121℃ for 45 minutes, and then cool it for later use.

[0087] (4) Breeding room: Select a sealed space, install an exhaust fan, turn on the exhaust fan for 8 hours every 3 days to promote air convection between the breeding room and the outside. Control the heater (oil heater, small heater, etc.) through the temperature controller to control the ambient temperature at 26±1℃. Install an industrial thermometer at the door of the breeding room to monitor the temperature inside the breeding room.

[0088] (5) Preparation of planarian breeding equipment: In the breeding room, add the breeding water from step (3) to the breeding basin from step (2), and keep the water level in the breeding basin 6cm. Take a 0.4cm hose and connect one end through the 0.4cm hole in the cover of the breeding basin from step (2) to the air stone. Put the air stone below the water level in the breeding basin from step (2), and connect the other end to the air pump. Turn on the air pump to supply oxygen and let it sit for more than 6 hours. Use a water dissolved oxygen meter to measure the dissolved oxygen content in the water. Adjust the air pump to keep the dissolved oxygen content in the water at 7 to 8 mg / L. Use an industrial thermometer to measure the water temperature and keep the water temperature at 22±1℃. If the water temperature exceeds the range, the ambient temperature should be adjusted.

[0089] (6) Planarian inoculation: Take 2000 planarian larvae that can prey on nematodes from the same batch of hatched larvae and add them to the culture basin using a 5mL pipette.

[0090] (7) Feeding method: Calculate the number of planarians and the amount of feed given on the day according to step S3. Add the amount of feed to the collection box of the feeding device through the feeding port every 4 days (i.e., feed once every 5 days). Pump the nematode solution into the planarian breeding pond through the feeding device. Estimate the amount of feed according to the number of planarians in the breeding pond. Use a timer to control the feeding device to feed quantitatively, or use a pipette or pipette.

[0091] Note: In this example, after 36 days of feeding, the planarian population in the rearing pond was visibly dense. Calculations showed that the number of planarians in the pond exceeded 180,000. The bottom area of ​​the rearing pond was 53cm × 32.5cm = 1722.5cm. 2 The average density is approximately 110 strands / cm². 2 The Logisstic equation was used to analyze the reproductive model of the planarian in the culture pond. Under limited conditions, the planarian's living space and food sources are limited, while the planarian population is close to the upper limit M. max When the planarian population increases to near zero, i.e., the growth rate k approaches zero, it indicates that the planarian stocking density is too high, approaching the upper limit of the planarian population in the stocking pond. Therefore, in this example, the planarians were transferred to new stocking tanks. In practical applications, the planarian population in the stocking pond should be transferred only when it reaches the upper limit M. max When the number of planarians in the culture pot reaches 80%, the planarians in the culture pot are transferred to a new culture pot to ensure rapid reproduction and avoid food waste.

[0092] Example 3

[0093] Taking terrestrial planarians collected from Guizhou soil in the laboratory as an example, they were fed with strips of pig liver, including the following steps:

[0094] S1. Data collection of planarian life cycle parameters: Ten planarians were placed in petri dishes for culture. The life cycle of planarians was observed under the feeding condition of strips of pig liver (1 mm long and 0.5 mm in diameter). The following parameters were recorded and averaged: lifespan of the planarian G = 20 days, sexual maturity period D = 7 days, oviposition period E = 13 days (the planarian disintegrated and died directly after laying the last egg), number of eggs laid N = 25.8, egg hatching period F = 4 days, hatching period f = 8 days, number of eggs hatched per n = 1, predation coefficient L = 1.2 (planarians / 2 days). Here, the predation coefficient L is the average number of strips of pig liver preyed by a single planarian every 2 days. Feeding was carried out once every 5 days to ensure that the planarians were in a state of starvation on the 5th day of the intermittent feeding every 5 days.

[0095] S2. Calculate the following parameters from the above parameters:

[0096] The average number of eggs laid per day during the spawning cycle is e = N / E = 2.0 (eggs / day);

[0097] The hatching rate P = 60.8%, which means the average daily hatching rate of egg masses during the incubation period is p = P / f = 7.6 (%).

[0098] S3. Establish a formula for calculating the number of planarians: The calculation here is the same as the steps in Example 1, and will not be repeated here.

[0099] S4. Establish a formula for calculating feed amount: Record the number of strip-shaped pig livers K (strips / g), i.e., feed amount (g) = number of planarians M. x ×1.2 / number of strips of pork liver K (strips / g), specific values ​​are shown in Table 3 below:

[0100]

[0101]

[0102] Preparation and implementation of relevant feeding conditions:

[0103] (1) Feed preparation: Take fresh pig liver, place it in a high-speed slicing machine, and set the slicing parameters to 1mm length and 0.5mm thickness.

[0104] (2) Breeding pot: Select a PVC plastic pot (with lid) with a length of 53cm × width of 32.5cm × height of 10cm. Drill a 0.4cm hole in the lid, clean it with detergent, and dry it in an oven at 50℃ for later use.

[0105] (3) Selection of aquaculture water: Use a 5L plastic bucket to collect tap water, place it in a sterilizer at 121℃ for 45 minutes, and then cool it for later use.

[0106] (4) Breeding room: Select a sealed space, install an exhaust fan, turn on the exhaust fan for 8 hours every 3 days to promote air convection between the breeding room and the outside. Control the heater (oil heater, small heater, etc.) through the temperature controller to control the ambient temperature at 26±1℃. Install an industrial thermometer at the door of the breeding room to monitor the temperature inside the breeding room.

[0107] (5) Preparation of planarian breeding equipment: In the breeding room, add the breeding water from step (3) to the breeding basin from step (2), and keep the water level in the breeding basin 6cm. Take a 0.4cm hose and connect one end through the 0.4cm hole in the cover of the breeding basin from step (2) to the air stone. Put the air stone below the water level in the breeding basin from step (2), and connect the other end to the air pump. Turn on the air pump to supply oxygen and let it sit for more than 6 hours. Use a water dissolved oxygen meter to measure the dissolved oxygen content in the water. Adjust the air pump to keep the dissolved oxygen content in the water at 7 to 8 mg / L. Use an industrial thermometer to measure the water temperature and keep the water temperature at 22±1℃. If the water temperature exceeds the range, the ambient temperature should be adjusted.

[0108] (6) Planarian inoculation: Take 2000 planarian larvae that can prey on nematodes from the same batch of hatched larvae and add them to the culture basin using a 5mL pipette.

[0109] (7) Feeding method: Calculate the number of planarians and the amount of feed given on the day according to step S3. Add the amount of feed to the collection box of the feeding device through the feeding port every 4 days (i.e., feed once every 5 days). Pump the nematode solution into the planarian breeding pond through the feeding device. Estimate the amount of feed according to the number of planarians in the breeding pond. Use a timer to control the feeding device to feed quantitatively, or use a pipette or pipette.

[0110] (8) Calculation of the number of strip-shaped pig livers K: Taking the first day of feeding 2100 strips / g as an example, weigh 1g of the strip-shaped pig livers cut in step (1), place them in a petri dish, add water to disperse the pig liver strips, and then count them under a microscope. Repeat 3 times. The results of the 3 counts are 2087, 2211, and 2056 strips, respectively. That is, the number of strip-shaped pig livers K = the sum of the 3 counts / 1g / 3 = (2087 + 2211 + 2056) / 1g / 3 = 2118 (strips / g).

[0111] Note: When using pig liver as feed and adopting this feeding method, first calculate the growth data for 61 days based on the model (i.e., feeding once every 5 days, for a total of 13 feedings). This can achieve rapid growth of planarians. However, in this experiment, by the 31st day (i.e., the 7th feeding), the water had become turbid and the planarians had died. This is related to the impact of pig liver feed on water quality, which led to a rapid increase in bacteria in the water. It is impossible to achieve the high-density, large-scale breeding as with nematode feeding. Therefore, when using this method and feeding with pig liver or egg yolk, it is necessary to increase the frequency of water changes or add a water purification device to the water.

[0112] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for feeding planarians, characterized in that: A formula for calculating the number of planarians is established based on the life history parameters of planarians. A breeding formula model for the entire breeding cycle of planarians is established by computer programming based on the planarian diet and the formula for calculating the number of planarians. The planarian diet includes the types of feed. The breeding formula model includes a formula for calculating the amount of feed. The breeding formula model calculates the amount of feed in the entire breeding cycle based on the initial number of planarians, the initial amount of feed, and the number of breeding days. The method specifically includes the following steps: S1. Collect planarian life cycle parameters: Take 10 planarians and place them in a petri dish for culture. Observe the life cycle of each planarian and record the following parameters, then take the average value: Planarian lifespan G is the time from the hatching of the larva to its death. Sexual maturity period D, which is the time from the hatching of larvae to the start of egg laying; The spawning cycle E is the time from the start of spawning to the end of spawning; Total number of eggs laid, N, is the total number of eggs laid during the spawning cycle; Egg incubation period F, which is the time from when the egg is laid to when it hatches; The incubation period f is the time from the start of incubation of the first egg mass to the end of incubation of the egg mass. The hatching number per egg, n, is the average number of larvae that hatch from each egg. Wherein, the units for the planarian lifespan G, sexual maturity period D, oviposition period E, egg hatching period F, and hatching period f are days, and the units for the total number of eggs laid N and the number of eggs hatched per egg n are individuals; S2. Calculate the following parameters from the above parameters: The average number of eggs laid per day, e, is the average number of eggs laid per day during the spawning cycle, e = N / E; The average daily hatching rate, p, is the average daily hatching rate of egg masses during the hatching period, p = P / f × 100%; Hatching rate P is the ratio of the total number of hatched eggs to the total number of eggs laid after the hatching cycle ends, which is calculated as total number of hatched eggs / total number of eggs laid × 100%. S3. Establish a formula for calculating the number of planarians: Let the number of planaria in the breeding pond on the xth day of breeding be M x , the number of hatched planaria be m x , the number of laid eggs be L x , and the initial number of planaria be a constant m0, then the relationship between x and m x satisfies: When 0 ≤ x ≤ D, the number of eggs laid is L. x The initial number is 0, meaning the same batch of planarians hatched on the first day are inoculated, i.e., the number of hatched planarians is m1 = m0, while the subsequent number of hatched planarians is m1 = m0. x The number of planarians, M, is 0, assuming no abnormal deaths. x =m0; When D < x < (D + F), the number of eggs laid is L. x =e(M x-D =em0, since the egg masses laid by planarians need to go through an egg hatching period F before they can hatch, the number of hatched eggs is m. x =0; while the number of planarians M x There are two cases: when x > G, then M x =0; conversely, when x≤G, then M x =m0; When x ≥ (D + F), the number of eggs laid is L. x =e[M (x-D) -∑(M x )], where ∑(M x The summation term is defined as x - G + 1 to xDE; when the planarian reaches the end of its lifespan (D + E = G), this summation term takes the constant value of 0, and it is also 0 when x ≤ (D + E) ≤ G; the number of hatched animals is m. x =np∑(L x ), where ∑(L x ) represents the summation term, with the summation range from xF-f+1 to xF; when xF-f+1≤0, the lower limit of the summation is taken as 1; Planarian number M x =M x-1 +m x -m x-G When xG≤0, then take m. x-G =0; S4. Assume the feed is live nematodes, that is, live nematodes are used for feeding: When live nematodes are used for feeding, the feeding amount is determined by the following formula: Feeding amount = Planarian number M x × Predation coefficient L / Nematode solution concentration K; where the nematode solution concentration K is in units of nematodes / mL, and the feeding amount is in units of mL, wherein: The method for calculating the nematode solution concentration K is as follows: nematode cultured in the laboratory is concentrated by filtration and washing to prepare a nematode mixture. Take 50 μL of the fully concentrated and mixed nematode mixture and observe the number of nematodes under a stereomicroscope. Repeat this process 3 times. The nematode solution concentration K = (total number of nematodes observed in 3 times) / 50 μL / 3 × 1000. The predation coefficient L is the average number of nematodes preyed on by a single planarian every 2 days, which is the average number of nematodes preyed on per day × 2. Planarian number M x The number of planarians in the culture pond on day x of culture.

2. The feeding method for planarian farming as described in claim 1, characterized in that: Replace the live nematodes in step S4 with strips of pig liver, each strip being 1 cm long and 0.5 cm in diameter. At this point: The amount of feed is determined by the following formula: Feed amount = Planarian number M x × Predation coefficient L / weight of strip-shaped pig liver K; the unit of feed amount is g, and the unit of weight of strip-shaped pig liver K is strip / g, wherein: The method for calculating the number of strips of pig liver K is as follows: Weigh 1g of the cut strips of pig liver, place them in a petri dish, add water to disperse the liver strips, and then count them under a microscope. Repeat this process 3 times. That is, the number of strips of pig liver K = the sum of the 3 counts / 1g / 3. The predation coefficient L is the average number of strips of pig liver consumed by a single planarian every 2 days, which is the average number of strips of pig liver consumed per day × 2. Planarian number M x The number of planarians in the culture pond on day x of culture.

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