A factory-scale recirculating aquaculture system for giant spiny loach

Abstract

This invention discloses a factory-scale recirculating aquaculture system (RAS) for the large-spined loach. The method specifically includes the following aspects: selection and pretreatment of the rearing pond, arrangement of habitat units, setting up feeding facilities, operation of the recirculating aquaculture system, and stocking and management of fry. The habitat unit consists of large-diameter and small-diameter pipes; multiple small-diameter pipes are evenly placed and fixed within each large-diameter pipe, with the axis of the small-diameter pipes parallel to the axis of the large-diameter pipes. The feeding facilities consist of multiple liftable feeding platforms evenly placed along the wall of a 6m diameter land-based circular rearing pond. This factory-scale RAS method, which provides a suitable habitat for the large-spined loach, adapts to its feeding habits, optimizes recirculating aquaculture system operating parameters, quantifies rearing density, and manages feeding, has significant practical implications and promotional value for overcoming the technical bottlenecks in large-scale large-spined loach farming and promoting the sustainable development of the industry.

Description

Technical Field

[0001] This invention relates to a factory-scale recirculating aquaculture method for giant spiny loach, belonging to the field of aquaculture technology. Background Technology

[0002] The giant spiny loach (Mastacembelus armatus), also known as the knife loach, spicy loach, or pig spiny loach, is a freshwater fish with extremely high economic value. Its tender flesh, delicious taste, and rich nutrition have made it popular with consumers in southern regions, leading to a continuously rising market price and promising prospects for aquaculture. However, the giant spiny loach possesses unique biological characteristics: it is a typical bottom-dwelling, burrowing fish, wary, timid, and photophobic, exhibiting poor adaptability to artificial breeding environments. Traditional aquaculture methods face numerous technical bottlenecks, severely restricting its large-scale, intensive aquaculture development.

[0003] Existing methods for farming giant spiny loach have the following shortcomings:

[0004] (a) Lack of suitable habitat design leads to strong stress response in giant spiny loach.

[0005] The spiny loach prefers to inhabit environments with hiding places, often hiding in crevices, caves, or among aquatic plants under natural conditions. In traditional aquaculture, ponds are often empty or only have a few coverings, failing to meet the spiny loach's need for concealed habitats. This lack of suitable habitat leads to chronic stress in the spiny loach, manifesting as decreased feed intake, slow growth, weakened immunity, and even attacks and external injuries, severely impacting survival rates and economic benefits. While existing technologies, such as CN201420827848.7's "A Spiny Loach Habitat," utilize a multi-layered PVC pipe structure to provide habitat, its complex structure and multi-layered design hinder water circulation at the bottom of the pond, easily causing localized water quality deterioration. Furthermore, cleaning and maintenance of the habitat are difficult.

[0006] (ii) The feeding method is not in line with the feeding habits of the giant spiny loach, resulting in feed waste and water pollution.

[0007] The spiny loach is nocturnal and benthic, preferring to forage at the bottom of the water at night or in low light conditions. However, traditional aquaculture often involves feeding directly onto the water surface or using fixed feeding platforms. During settling, the feed is easily dispersed by the water flow, and some of it remains undetected and uneaten by the loaches, resulting in waste. Uneaten feed decomposes at the bottom of the pond, increasing aquaculture costs and leading to elevated ammonia and nitrite levels, water quality deterioration, and disease outbreaks. While existing recirculating aquaculture systems can purify water to some extent, improper feeding methods can still burden water treatment systems and increase operating costs.

[0008] (iii) The operating parameters of the circulating water system lack systematic optimization for the giant spiny loach.

[0009] Recirculating aquaculture is an important model for high-density, factory-style aquaculture, offering advantages such as water conservation, environmental friendliness, and high controllability. However, existing recirculating aquaculture technologies for giant spiny loach (such as the "Simple Recirculating Aquaculture System and Method for Giant Spinach" disclosed in CN201910419535.5) mainly focus on the construction of the system structure and the implementation of water circulation. They lack refined and systematic parameter optimization for specific operating parameters of the recirculating aquaculture system (such as hydraulic retention time, dissolved oxygen content, temperature, pH value, and control thresholds for ammonia nitrogen and nitrite) at different growth stages of giant spiny loach. Giant spiny loach have different water quality requirements at different growth stages; improper parameter settings can, at best, affect growth rate, and at worst, lead to mass mortality of fry.

[0010] (iv) The lack of quantitative standards for stocking density and feeding management results in poor technical reproducibility.

[0011] In the artificial breeding of giant spiny loach, stocking density is one of the key factors affecting breeding efficiency. Currently, the stocking density of giant spiny loach is mostly determined by experience, lacking scientific quantitative standards for different sizes of fry. Too high a density can easily lead to water quality deterioration and frequent disease outbreaks, while too low a density results in low utilization of breeding facilities and insufficient output per unit area. At the same time, feeding management also lacks standardized operating procedures to match facilities such as height-adjustable feeding platforms and habitat units, making it difficult to reliably reproduce the technical solutions in industrial promotion. Summary of the Invention

[0012] The purpose of this invention is to provide a factory-scale recirculating aquaculture system for giant spiny loach. This factory-scale recirculating aquaculture system, which provides a suitable habitat for giant spiny loach, adapts to its feeding habits, optimizes recirculating aquaculture parameters, and quantifies stocking density and feeding management, has significant practical implications and promotional value for overcoming the technical bottlenecks in large-scale giant spiny loach farming and promoting the sustainable development of the industry.

[0013] The technical solution of the present invention is a factory-scale recirculating aquaculture method for giant spiny loach, the method specifically including the following aspects: selection and pretreatment of culture ponds, arrangement of habitat units, setting up of feeding facilities, operation of recirculating aquaculture system, and seedling release and culture management.

[0014] In the aforementioned method for the industrialized recirculating aquaculture of giant spiny loach, the selection and pretreatment of the culture pond specifically involves: selecting a land-based circular culture pond with a diameter of 6m, the culture pond being compatible with a conventional industrialized recirculating aquaculture system, thoroughly cleaning and disinfecting the culture pond before culture, rinsing it clean with clean water after disinfection, and injecting clean water pretreated by the recirculating aquaculture system, with the water level controlled at 1.2 to 1.5m.

[0015] In the aforementioned method for the factory-scale recirculating aquaculture of giant spiny loach, the habitat unit is specifically arranged as follows: habitat units are evenly placed around the bottom of the land-based circular aquaculture pond, and the habitat unit consists of large-diameter pipes and small-diameter pipes; multiple small-diameter pipes are evenly placed and fixed in each large-diameter pipe, and the axis of the small-diameter pipes is parallel to the axis of the large-diameter pipes.

[0016] In the aforementioned method for the factory-scale recirculating aquaculture of giant spiny loach, the feeding facilities are specifically set up as follows: multiple liftable feeding platforms are evenly set up along the pond wall of the land-based circular aquaculture pond. When feeding, the feeding platforms are adjusted to 50cm below the water surface. After feeding for 1.5 hours, the feeding platforms are raised above the water surface to observe the feeding situation, thereby adjusting the feeding amount accordingly and cleaning up the uneaten feed on the feeding platforms.

[0017] In the aforementioned method for intensive recirculating aquaculture of giant spiny loach, the operation of the recirculating aquaculture system is specifically as follows: the operating parameters of the recirculating aquaculture system are adjusted according to the growth stage of the giant spiny loach. During the juvenile stage, the water circulation rate is controlled to circulate once every 2 to 3 hours, and during the adult stage, it is controlled to circulate once every 1 to 2 hours. The dissolved oxygen content in the water is maintained at ≥6 mg / L, the water temperature is controlled at 20 to 29℃, the pH value is controlled at 7.0 to 8.5, the ammonia nitrogen content is lower than 0.2 mg / L, and the nitrite content is lower than 0.1 mg / L.

[0018] In the aforementioned intensive recirculating aquaculture method for giant spiny loach, the seedling stocking and aquaculture management specifically involve: selecting uniformly sized, robust, disease-free, and injury-free giant spiny loach seedlings; adjusting the stocking density according to seedling size, with a stocking density of 80-100 seedlings / m² for seedlings 3-5cm in length, 50-80 seedlings / m² for seedlings 5-10cm in length, and 30-50 seedlings / m² for seedlings over 10cm in length; after stocking, feeding is done at regular intervals and in fixed quantities using a liftable feeding platform, with the feeding amount adjusted according to the giant spiny loach's feeding behavior, feeding 3-4 times daily during the juvenile stage and 2-3 times daily during the adult stage, with each feeding amount sufficient for the giant spiny loach to consume within 1-2 hours; regularly checking the integrity of the habitat units and the flexibility of the feeding platform, promptly cleaning uneaten feed and feces, and regularly cleaning and disinfecting the aquaculture pond and recirculating aquaculture system to prevent disease outbreaks.

[0019] In the aforementioned method for industrialized recirculating aquaculture of giant spiny loach, the large-diameter pipe and the small-diameter pipe are PVC pipes.

[0020] The beneficial effects of the present invention are as follows: Compared with the prior art, the present invention, by adopting the above-described technical solution, achieves the following effects:

[0021] 1. Significantly reduces stress response in giant spiny loach and improves survival rate.

[0022] This invention simulates the concealed space required by the giant spiny loach in its natural habitat by setting up habitat units composed of large and small pipes within its living space. This effectively eliminates the anxiety and stress response of the giant spiny loach in empty ponds. The habitat unit adopts a "pipe-within-a-pipe" structure, with multiple small-diameter pipes inside a large-diameter pipe. This satisfies the giant spiny loach's burrowing habit and makes full use of the three-dimensional space at the bottom of the breeding pond. At the same time, the gaps between the small-diameter pipes ensure water circulation at the bottom of the pond, avoiding the problem of localized water quality deterioration that is easily caused by traditional multi-layered habitat platforms. Practice shows that after adopting the habitat unit of this invention, the survival rate of giant spiny loach is increased by more than 15% compared with traditional breeding methods.

[0023] 2. Improve feed intake rate and reduce feed waste and water pollution.

[0024] This invention addresses the benthic feeding habits of the giant spiny loach by incorporating a height-adjustable feeding platform. During feeding, the platform is adjusted to 50cm below the water surface, releasing feed into the lower water layer to match the loach's feeding depth, significantly improving feed discovery and consumption rates. The height-adjustable design also facilitates the removal of uneaten feed after feeding, preventing feed from scattering and decaying at the bottom of the pond, thus protecting the water quality. Removing uneaten feed 1.5 hours after feeding, combined with the filtration function of the circulating water system, effectively maintains the cleanliness of the aquaculture water and reduces the water treatment load.

[0025] 3. Achieve refined and phased management of the circulating water system.

[0026] This invention addresses the different water quality and circulation rate requirements of juvenile and adult spiny loaches at different growth stages. It sets control parameters for water circulation rate, dissolved oxygen, temperature, pH, ammonia nitrogen, and nitrite, enabling quantitative management and phased regulation of circulating water parameters. During the juvenile stage, the fish have a high metabolic rate and are sensitive to water quality; a slower circulation rate (circulating once every 2-3 hours) avoids excessively rapid water flow that could shock them. During the adult stage, the fish have a high metabolic load; a faster circulation rate (circulating once every 1-2 hours) can promptly remove metabolic waste and maintain stable water quality.

[0027] 4. Provide scientifically quantified stocking density and feeding management plans.

[0028] This invention provides recommended stocking densities of 80-100 fish / m², 50-80 fish / m², and 30-50 fish / m² for different sizes of large spiny loach (3-5cm, 5-10cm, and over 10cm), ensuring efficient utilization of aquaculture facilities while avoiding stress and disease caused by overcrowding. Quantitative management of feeding frequency and amount (3-4 times / day for juveniles, 2-3 times / day for adults, with each feeding amount based on 1-2 hours of consumption) standardizes and replicates aquaculture operations, facilitating industry-wide promotion.

[0029] 5. Significant overall benefits

[0030] Compared with existing traditional farming methods, the method of this invention for raising giant spiny loach can achieve the following: a 15% to 25% increase in survival rate, a 10% to 15% decrease in feed conversion ratio, a 20% to 30% increase in yield per unit area, and a water recycling rate of over 90%. This significantly reduces farming costs and environmental impact, resulting in significant economic and ecological benefits. Attached Figure Description

[0031] Figure 1 A pond structure equipped with a liftable feeding platform and a habitat unit;

[0032] Figure 2 This is a schematic diagram of the habitat unit.

[0033] Figure 3 for Figure 2 Side view.

[0034] Attached diagram labels: 1-Large diameter pipe, 2-Small diameter pipe. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0036] An embodiment of the present invention: a factory-scale recirculating aquaculture method for giant spiny loach, the method specifically includes the following aspects: selection and pretreatment of culture ponds, arrangement of habitat units, setting up of feeding facilities, operation of recirculating aquaculture system, and seedling release and culture management.

[0037] 1. Selection and pretreatment of aquaculture ponds: Select a land-based circular aquaculture pond with a diameter of 6m. This aquaculture pond is compatible with conventional factory-style circulating water systems, which can realize water circulation filtration, oxygenation and temperature control. Before aquaculture, thoroughly clean and disinfect the aquaculture pond. After disinfection, rinse it with clean water and fill it with clean water that has been pretreated by the circulating water system. The water level is controlled at 1.2-1.5m.

[0038] 2. Habitat Arrangement: Habitat units are evenly placed around the bottom of the land-based aquaculture pond. Each habitat unit consists of a large-diameter pipe 1 and a small-diameter pipe 2. The large-diameter pipe 2 has a length of 50cm and a diameter of 25cm, while the small-diameter pipe 2 has a length of 45cm and a diameter of 3cm. Six small-diameter pipes 2 are evenly arranged and fixed within each large-diameter pipe 1. The axis of the small-diameter pipe 2 is parallel to the axis of the large-diameter pipe 1, and the spacing between adjacent small-diameter pipes 2 is uniform. The number of habitat units is adjusted according to the size of the aquaculture pond to ensure that the giant spiny loach has sufficient habitat space without affecting the water circulation at the bottom of the pond.

[0039] Both large-diameter and small-diameter pipes are made of PVC. PVC pipes are non-toxic, corrosion-resistant, and will not pollute water bodies. They are also easy to clean and maintain.

[0040] 3. Feeding facility setup: Four adjustable feeding platforms are evenly placed along the wall of a 6m diameter land-based circular aquaculture pond. The platforms are made of corrosion-resistant, non-toxic hard material. The height of the platforms can be adjusted according to changes in the water level of the aquaculture pond and the growth stage of the spiny loach. The spiny loach is nocturnal and prefers to feed on the bottom. When feeding, the platforms are adjusted to 50cm below the water surface to suit its feeding habits, making it easier for the spiny loach to dive down and feed, while avoiding feed scattering to the bottom of the pond, which would cause waste and water pollution. The platforms are used to feed eel food, which is suitable for the feeding habits of the spiny loach.

[0041] 4. Operation of the recirculating water system: Start the conventional factory-style recirculating water system, including filtration, aeration, temperature control, and disinfection devices, to ensure smooth water circulation in the breeding ponds. The operating parameters of the recirculating water system are adjusted according to the growth stages of the giant spiny loach. During the juvenile stage, the water circulation rate is controlled at once every 2 to 3 hours, and during the adult stage, it is controlled at once every 1 to 2 hours. Maintain the dissolved oxygen content in the water at no less than 6 mg / L, the water temperature at 20 to 29℃, the pH value at 7.0 to 8.5, the ammonia nitrogen content at less than 0.2 mg / L, and the nitrite content at less than 0.1 mg / L.

[0042] 5. Seedling Stocking and Rearing Management: Select uniformly sized, robust, and disease-free spiny loach seedlings. Adjust the stocking density according to seedling size: 80-100 seedlings / m² for 3-5cm seedlings, 50-80 seedlings / m² for 5-10cm seedlings, and 30-50 seedlings / m² for seedlings over 10cm. After stocking, provide eel feed at regular intervals and in measured quantities using a height-adjustable feeding platform. Adjust the feeding amount based on the spiny loach's feeding behavior. During the juvenile stage, feed 3 times daily. Feed the fish 2-3 times a day during the adult stage, with each feeding amount being enough for the spiny loach to finish eating within 1-2 hours. When feeding, adjust the feeding platform to 50cm below the water surface to facilitate feeding. 1.5 hours after feeding, raise the feeding platform above the water surface to facilitate observation of feeding and adjust the feeding amount accordingly. Clean up any uneaten food on the feeding platform. Regularly check the integrity of the habitat and the flexibility of raising and lowering the feeding platform, and promptly clean up uneaten food and feces. Regularly clean and disinfect the breeding pond and circulating water system to prevent disease outbreaks.

Claims

1. A method for intensive recirculating aquaculture of giant spiny loach, characterized in that: The method specifically includes the following aspects: selection and pretreatment of breeding ponds, arrangement of habitat units, setting up of feeding facilities, operation of recirculating water system, and seedling release and breeding management.

2. The method for industrialized recirculating aquaculture of giant spiny loach according to claim 1, characterized in that: The selection and pretreatment of the aquaculture pond are as follows: a land-based circular aquaculture pond with a diameter of 6m is selected. The aquaculture pond is compatible with a conventional factory-style circulating water system. Before aquaculture, the aquaculture pond is thoroughly cleaned and disinfected. After disinfection, it is rinsed with clean water and filled with clean water that has been pretreated by the circulating water system. The water level is controlled at 1.2 to 1.5m.

3. The method for industrialized recirculating aquaculture of giant spiny loach according to claim 1, characterized in that: The habitat unit is arranged as follows: habitat units are evenly placed around the bottom of the land-based aquaculture circular pond. The habitat unit consists of a large-diameter pipe (1) and a small-diameter pipe (2). Multiple small-diameter pipes (2) are evenly placed and fixed in each large-diameter pipe (1), and the axis of the small-diameter pipe (2) is parallel to the axis of the large-diameter pipe (1).

4. The method for industrialized recirculating aquaculture of giant spiny loach according to claim 1, characterized in that: The feeding facility is specifically set up as follows: multiple liftable feeding platforms are evenly set up along the pond wall of the land-based aquaculture circular pond. When feeding, the feeding platform is adjusted to 50cm below the water surface. After feeding for 1.5 hours, the feeding platform is raised above the water surface to observe the feeding situation, thereby adjusting the feeding amount accordingly and cleaning up the uneaten feed on the feeding platform.

5. The method for industrialized recirculating aquaculture of giant spiny loach according to claim 1, characterized in that: The specific operation of the circulating water system is as follows: the operating parameters of the circulating water system are adjusted according to the growth stage of the giant spiny loach. During the juvenile stage, the water circulation rate is controlled to circulate once every 2 to 3 hours, and during the adult stage, it is controlled to circulate once every 1 to 2 hours. The dissolved oxygen content in the water is maintained at ≥6 mg / L, the water temperature is controlled at 20 to 29℃, the pH value is controlled at 7.0 to 8.5, the ammonia nitrogen content is lower than 0.2 mg / L, and the nitrite content is lower than 0.1 mg / L.

6. The method for intensive recirculating aquaculture of giant spiny loach according to claim 1, characterized in that: The specific procedures for stocking and raising the fry are as follows: Select uniformly sized, robust, and disease-free spiny loach fry. Adjust the stocking density according to the fry size: 80-100 fry / m² for fry with a body length of 3-5cm, 50-80 fry / m² for fry with a body length of 5-10cm, and 30-50 fry / m² for fry with a body length of over 10cm. After stocking, feed the fry with eel feed at regular intervals and in measured amounts using a liftable feeding platform. Adjust the feeding amount according to the fry's feeding behavior. Feed the fry 3-4 times a day, and the adult fry 2-3 times a day. Each feeding should be sufficient for the fry to finish eating within 1-2 hours. Regularly check the integrity of the habitat and the flexibility of the feeding platform, promptly remove uneaten feed and feces, and regularly clean and disinfect the breeding pond and circulating water system to prevent disease outbreaks.

7. The method for industrialized recirculating aquaculture of giant spiny loach according to claim 3, characterized in that: The large-diameter pipe (1) and the small-diameter pipe (2) are PVC pipes.

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