Intermediate breeding device and method for shellfish seedlings

Abstract

The invention belongs to the technical field of breeding, and particularly discloses a shellfish seedling intermediate breeding device and method.The breeding device is overall in a cube shape, the cube is formed by connecting steel structure frames, the steel structure frames comprise a plurality of transverse supports and a plurality of stand columns, and the interior of the cube is hollow and provided with a plurality of breeding layers; each seedling raising layer comprises a plurality of raising units, a plurality of fixing supports perpendicular to the stand columns are arranged between the adjacent stand columns in the length direction of the stand columns at equal intervals, the fixing supports on the four side faces of the cube correspondingly define the seedling raising layers, and a plurality of limiting supports which are arranged in a transversely-longitudinally staggered mode are arranged between the fixing supports of each seedling raising layer. And the breeding units are detachably limited and embedded between the limiting brackets. According to the shellfish larva intermediate breeding device and method, larva intermediate breeding is conducted on the sea through facilities, the blank of the intermediate breeding link of shellfishes such as solen grandis and panopea abrupta is filled, and the specification of bottom sowing of the shellfish larva and the survival rate of the shellfish larva are improved.

Description

Technical Field

[0001] The invention relates to the technical field of seedling cultivation, and in particular to a shellfish seedling intermediate cultivation device and method. Background Art

[0002] The large bamboo clam is a mollusk of the genus Bambusa in the family Bambusidae. It is enlarged, with particularly developed foot muscles and extremely delicious taste. It is an important economic shellfish in China. It has the effects of nourishing and promoting lactation as medicine, and its shell can also be used as medicine. The shell of the large bamboo clam is long, generally 4 to 5 times the shell height. The two shells embrace each other in a bamboo tube shape, with front and back openings, and exposed flesh on the outside of the shell. The top of the shell is located at the front end, the dorsal and ventral edges of the shell are parallel, the surface is smooth without radial ribs, the growth lines are obvious, and sometimes there are light red color bands. The large bamboo clam lives in the mud and sand from the middle and lower areas of the intertidal zone to the shallow sea, with a burial depth of 30 to 40 cm and an inclined cave. It is a filter-feeding animal, mainly feeding on benthic diatoms and organic debris near the shore, and is widely distributed along the coast of my country. There is currently no intermediate breeding method or facility for large bamboo clams. After the juveniles are released from the nursery, they are usually sown directly into the sea. Since the seedlings are usually only a few millimeters in size and have poor ability to resist enemies and the natural environment, most of them die after bottom sowing and the survival rate is extremely low.

[0003] Geoduck, also known as the sea god clam, is a high-end economic shellfish with a large market demand and a high price. The two shells are small and usually equal. There are serrated teeth on the front end of the shell, and there are secondary shells on the back, abdomen and rear end of the dorsal shell. The water pipe is extremely developed and the thick water pipe cannot be completely retracted into the shell. It is shaped like an elephant's trunk, hence the name. Geoduck lives in sea areas with water temperatures of 0℃-24℃, salinity of 26-34, water depth of 6 meters to 30 meters, and muddy bottoms. It feeds on single-cell algae in seawater and can also filter sediments and organic debris. Geoduck grows faster in the first four years. As it ages, the growth of the shell gradually slows down, but the soft body can continue to grow, and its lifespan can reach more than 100 years. In countries with mature seedling cultivation technology, geoducks have a relatively complete set of seedling intermediate cultivation technology and facilities. However, my country's scientific research institutions have only mastered artificial seedling cultivation technology in recent years, and large-scale production and promotion have not yet been carried out. At present, my country does not have methods and equipment for intermediate seedling cultivation. Judging from the results of the early bottom seeding tests, the survival rate of seedlings is extremely low due to the lack of intermediate cultivation process. Summary of the invention

[0004] The purpose of the present invention is to provide a shellfish seedling intermediate cultivation device and method, which fills the gap in the intermediate cultivation link of shellfish such as large bamboo clams and geoducks by carrying out intermediate cultivation of seedlings at sea with facilities, and improves the specifications and survival rate of shellfish seedlings bottom sowing.

[0005] To achieve the above-mentioned purpose, the present invention provides an intermediate incubation device for shellfish seedlings. The incubation device is in the shape of a cube as a whole. The cube is connected by a steel structure frame. The steel structure frame includes multiple transverse supports and multiple columns. The interior of the cube is hollow and multiple seedling layers are arranged. Each seedling layer includes multiple incubation units. Between adjacent columns, multiple fixed supports perpendicular to the columns are evenly spaced along the length direction of the columns. The fixed supports on the four sides of the cube correspondingly form seedling layers. A number of limit supports arranged in a staggered manner in a horizontal and vertical direction are arranged between the fixed supports of each seedling layer. The incubation units are detachably limited and embedded between the limit supports.

[0006] Preferably, the plurality of transverse supports and the plurality of uprights cooperate with each other to form a cubic frame through connection components and bolt connections.

[0007] Preferably, a cross bracket is provided above the raising unit of the seedling raising layer of the top layer, and the ends of the cross bracket are respectively connected with the transverse bracket bolts.

[0008] Preferably, the ends of the fixed bracket are respectively connected to the corresponding column bolts, and the transverse bracket, the limiting bracket and the fixed bracket are all angle steels.

[0009] Preferably, the growing units are arranged in a rectangular array on the seedling raising layer, and gaps are provided between adjacent growing units and adjacent seedling raising layers.

[0010] Preferably, a bottom support is provided at the bottom of the column.

[0011] Preferably, hooks are provided at the four corners of the top of the steel structure frame for the placement and harvesting of the shellfish seedling intermediate cultivation device.

[0012] Preferably, the breeding unit is a hard cage, in which a substrate conducive to shellfish burrowing in the sand is placed, and the top of the cage is covered with nylon netting to prevent predators from invading.

[0013] The present invention also provides a method for intermediate cultivation of shellfish seedlings, which is realized by a cultivation device and comprises the following steps: Step (1) Sea area selection: select a sea area with a water depth of 5-15 meters, a seawater flow rate of 0.2-0.75 meters per second, a seawater salinity of more than 25, rich plankton, a seabed bearing capacity of more than 2 tons per square meter, and a seabed mud thickness of less than 20 centimeters; Step (2) assembling the intermediate rearing device, transporting the steel structure frame and rearing units of the shellfish fry intermediate rearing device to the shore of the deployment area, or assembling them on the deployment ship, and opening several rearing units to prepare for the transfer of juvenile spat; Step (3) selecting spat, selecting spat with a shell length of 2-10 mm, placing the spat in a culture unit with a pre-laid substrate conducive to shellfish burrowing, and scattering the spat on the surface of the substrate conducive to shellfish burrowing at a density of 1 spat / cm2. After the spat burrows into the substrate, the culture unit is immediately installed in the steel structure frame of the shellfish seedling intermediate culture device and fixed, ready for release; Step (4) placing and managing the intermediate rearing devices: placing the intermediate rearing devices containing juvenile shellfish in the selected sea area, with the interval between adjacent intermediate rearing devices being no less than 20 meters. During the rearing period, sampling should be taken at fixed points every week to observe the growth and survival of the shellfish seedlings; Step (5) After the spawning, the device is collected. When the juvenile spat grows to a shell length greater than 15 mm, the shellfish fry are harvested for later cultivation. The substrate that is conducive to the shellfish burrowing is washed down together with the shellfish fry, and the substrate that is conducive to the shellfish burrowing is filtered out for recycling. The shellfish fry are carefully collected and counted for bottom seeding.

[0014] Preferably, in step (3), the young shellfish is one of the group consisting of giant bamboo clam and geoduck.

[0015] The advantages and beneficial effects of the present invention using the above-mentioned shellfish seedling intermediate cultivation device and method are: 1. The present invention proposes a new model for intermediate breeding of shellfish seedlings in submarine facilities, which fills the gap in the intermediate breeding of buried shellfish in China. At the same time, it is naturally bred in the sea area, which meets the requirements of green ecological aquaculture production, and solves the problems of weak ability to resist enemies and poor ability to adapt to the external environment of buried shellfish such as large bamboo clams and geoducks in the seedling stage.

[0016] 2. The device of the present invention adopts a multi-layer cubic frame to open, disassemble and install the breeding unit structure. The multi-layer cubic frame is an assembled steel structure. Angle steel is used to facilitate the positioning and limit the installation of the breeding unit cage. It is low in cost and easy to operate, with a high degree of intensiveness. The net covering the top of the cage protects the shellfish seedlings from enemy invasion, greatly improving the survival rate and providing healthy seedlings for bottom sowing and proliferation.

[0017] 3. The device of the present invention forms its own aquaculture space, and the size of the device can be flexibly set according to the aquaculture scale, sea conditions, etc. The device can be mechanically hoisted, put into use, and harvested, which saves manpower and material resources and is highly efficient, meeting the needs of modern fishery development.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a shellfish seedling intermediate cultivation device of the present invention; Figure 2 It is a side schematic diagram of a shellfish seedling intermediate cultivation device of the present invention; Figure 3 It is another side schematic diagram of a shellfish seedling intermediate cultivation device of the present invention; Figure 4 The present invention is a top view of a shellfish seedling intermediate cultivation device.

[0020] Reference numerals 1. Horizontal bracket; 2. Hook; 3. Cultivation unit; 4. Fixed bracket; 5. Limit bracket; 6. Column; 7. Bottom support; 8. Connection component; 9. Cross bracket. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0022] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] Example 1 A shellfish seedling intermediate incubation device, the incubation device is in the shape of a cube as a whole, the cube is connected by a steel structure frame, the steel structure frame includes a plurality of transverse brackets 1 and a plurality of columns 6, and the transverse brackets 1 are angle steels. The plurality of transverse brackets 1 and the plurality of columns 6 cooperate with each other to form a cube frame through a connection assembly 8 and bolt connection. The connection assembly 8 includes an angle connector and a plate connector for locking connection. The connection assembly 8 belongs to the prior art.

[0024] The cube is hollow inside and is provided with multiple seedling raising layers, each seedling raising layer includes multiple raising units 3, and multiple fixed brackets 4 perpendicular to the columns 6 are evenly spaced between adjacent columns 6 along the length direction of the columns 6. The fixed brackets 4 on the four sides of the cube form corresponding seedling raising layers, and a number of limit brackets 5 arranged in a horizontal and vertical staggered manner are provided between the fixed brackets 4 of each seedling raising layer, and the raising units 3 can be removably limited and embedded between the limit brackets 5.

[0025] Multiple fixed brackets 4 are evenly spaced between the columns 6 on both sides of each side of the cube, and the ends of the fixed brackets 4 are bolted to the corresponding columns 6. Four fixed brackets 4 located in the same plane enclose a seedling layer, and multiple limit brackets 5 arranged in a horizontal and vertical staggered manner are arranged between the four fixed brackets 4. The limit brackets 5 and the fixed brackets 4 are angle steels, and the limit brackets 5 and the fixed brackets 4 form a frame for placing the cultivation unit 3. The cultivation unit 3 can be detachably embedded in the frame composed of the limit brackets 5 and the fixed brackets 4.

[0026] A cross bracket 9 is arranged above the cultivation unit 3 of the top seedling raising layer, and the ends of the cross bracket 9 are respectively bolted to the transverse bracket 4. The cross bracket 9 can improve the stability of the cubic frame structure.

[0027] The growing units 3 are arranged in a rectangular array on the seedling raising layer, and gaps are provided between adjacent growing units 3 and adjacent seedling raising layers to maintain water permeability. In order to enhance the stability of each seedling raising layer, reinforcing ribs (not shown in the figure) can be provided above the growing units 3 of the seedling raising layer below the top layer, and both ends of the reinforcing ribs are bolted to the fixing bracket 4.

[0028] A bottom support 7 is provided at the bottom of the column 6 to prevent the accumulation of seabed mud under the device.

[0029] The four corners of the top of the steel structure frame are provided with hooks 2 for the placement and harvesting of the shellfish seedling intermediate cultivation device.

[0030] The rearing unit 3 is a hard cage, in which a substrate conducive to shellfish burrowing is placed, and the top of the cage is covered with nylon netting to prevent predators from invading.

[0031] A method for intermediate cultivation of shellfish seedlings comprises the following steps: Step (1) Sea area selection: select a sea area with a water depth of 5-15 meters, a seawater flow rate of 0.2-0.75 meters per second, a seawater salinity of more than 25, rich plankton, a seabed bearing capacity of more than 2 tons per square meter, and a seabed mud thickness of less than 20 centimeters; Step (2) assembling the intermediate incubation device, transporting the steel structure frame and the incubation units 3 of the shellfish fry intermediate incubation device to the shore of the deployment sea area, or assembling them on the deployment ship, and opening several incubation units 3 to prepare for the transfer of juvenile shellfish; Step (3) selecting spat, selecting spat of large bamboo clams or geoduck, selecting spat with a shell length of 2-10 mm, placing the spat in a cultivation unit 3 which has been pre-arranged with a substrate conducive to shellfish burrowing, and scattering the spat on the surface of the substrate conducive to shellfish burrowing at a density of 1 spat / cm2, and after the spat burrows into the substrate, immediately installing the cultivation unit 3 in a steel structure frame of the intermediate cultivation device for shellfish spats, and preparing for release; Step (4) placing and managing the intermediate rearing devices: placing the intermediate rearing devices containing juvenile shellfish in the selected sea area, with the interval between adjacent intermediate rearing devices being no less than 20 meters. During the rearing period, sampling should be taken at fixed points every week to observe the growth and survival of the shellfish seedlings; Step (5) After the spawning, the device is collected. When the juvenile spat grows to a shell length greater than 15 mm, the shellfish fry are harvested for later cultivation. The substrate that is conducive to the shellfish burrowing is washed down together with the shellfish fry, and the substrate that is conducive to the shellfish burrowing is filtered out for recycling. The shellfish fry are carefully collected and counted for bottom seeding.

[0032] The above-mentioned breeding method was used to breed intermediate shellfish seedlings using large bamboo clam and geoduck seedlings as experimental objects: Test sea area: Shicheng Island sea area, Zhuanghe, Dalian, Liaoning Province; Experimental period: mid-March to early August; Sea environment: water depth 15 meters, seawater flow rate less than 0.5 meters per second, seawater salinity of about 30, water temperature 5.2-19.8℃. The seeding density in each unit cell of the experimental device is 200,000 seeds. The initial specifications of geoduck seedlings are shell length 3.2±0.6mm, and the initial specifications of large bamboo clam seedlings are shell length 2.5±0.4mm. At the end of the experiment, the shell length of large bamboo clams increased to 16.4±1.4mm, and the shell length of geoduck increased to 17.6±2.6mm. During the experiment, the survival rate of large bamboo clam seedlings was 71.5%, and the survival rate of geoduck seedlings was 67.2%.

[0033] Device advantages: high survival rate of seedlings (survival rate of large bamboo clams and geoducks in bottom seeding proliferation mode is 1%-5%), and easy to centrally harvest and cultivate.

[0034] Therefore, the present invention adopts the above-mentioned shellfish seedling intermediate cultivation device and method, and fills the gap in the intermediate cultivation link of shellfish such as large bamboo clams and geoducks by carrying out intermediate cultivation of seedlings at sea with facilities, thereby improving the specifications and survival rate of bottom sowing of shellfish seedlings.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A shellfish seedling intermediate cultivation device, characterized in that: The cultivation device is in the shape of a cube as a whole, and the cube is connected by a steel structure frame. The steel structure frame includes multiple horizontal brackets and multiple columns. The interior of the cube is hollow and multiple seedling layers are arranged. Each seedling layer includes multiple cultivation units. Between adjacent columns, multiple fixed brackets perpendicular to the columns are evenly spaced along the length direction of the columns. The fixed brackets on the four sides of the cube form seedling layers accordingly. Several limit brackets arranged in a staggered manner in both horizontal and vertical directions are arranged between the fixed brackets of each seedling layer. The cultivation unit can be removably limited and embedded between the limit brackets.

2. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: The plurality of transverse supports and the plurality of uprights cooperate with each other and are connected through connecting components and bolts to form a cubic frame.

3. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: A cross bracket is arranged above the raising unit of the seedling raising layer on the top layer, and the ends of the cross bracket are respectively connected with the transverse bracket bolts.

4. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: The ends of the fixed bracket are respectively connected with corresponding column bolts, and the transverse bracket, the limiting bracket and the fixed bracket are all angle steels.

5. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: The growing units are arranged in a rectangular array on the seedling raising layer, and gaps are provided between adjacent growing units and adjacent seedling raising layers.

6. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: A bottom support is provided at the bottom of the column.

7. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: The four corners of the top of the steel structure frame are provided with hooks for the placement and harvesting of the shellfish seedling intermediate cultivation device.

8. The shellfish seedling intermediate cultivation device according to claim 1, characterized in that: The breeding unit is a hard cage, in which a substrate conducive to shellfish burrowing in the sand is placed, and the top of the cage is covered with nylon netting to prevent enemy invasion.

9. A method for intermediate cultivation of shellfish seedlings, characterized in that: The method is realized by the incubation device according to any one of claims 1 to 8, comprising the following steps: Step (1) Sea area selection: select a sea area with a water depth of 5-15 meters, a seawater flow rate of 0.2-0.75 meters per second, a seawater salinity of more than 25, rich plankton, a seabed bearing capacity of more than 2 tons per square meter, and a seabed mud thickness of less than 20 centimeters; Step (2) assembling the intermediate rearing device, transporting the steel structure frame and rearing units of the shellfish fry intermediate rearing device to the shore of the deployment area, or assembling them on the deployment ship, and opening several rearing units to prepare for the transfer of juvenile spat; Step (3) selecting spat, selecting spat with a shell length of 2-10 mm, placing the spat in a culture unit with a pre-laid substrate conducive to shellfish burrowing, and scattering the spat on the surface of the substrate conducive to shellfish burrowing at a density of 1 spat / cm2. After the spat burrows into the substrate, the culture unit is immediately installed in the steel structure frame of the shellfish seedling intermediate culture device and fixed, ready for release; Step (4) placing and managing the intermediate rearing devices: placing the intermediate rearing devices containing juvenile shellfish in the selected sea area, with the interval between adjacent intermediate rearing devices being no less than 20 meters. During the rearing period, sampling should be taken at fixed points every week to observe the growth and survival of the shellfish seedlings; Step (5) After the spawning, the device is collected. When the juvenile spat grows to a shell length greater than 15 mm, the shellfish fry are harvested for later cultivation. The substrate that is conducive to the shellfish burrowing is washed down together with the shellfish fry, and the substrate that is conducive to the shellfish burrowing is filtered out for recycling. The shellfish fry are carefully collected and counted for bottom seeding.

10. The method for intermediate cultivation of shellfish seedlings according to claim 9, characterized in that: In step (3), the juvenile shellfish is a kind of razor clam or geoduck.

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