A method for improving the peeling specifications of sea urchin seedlings

Abstract

The present invention discloses a method for improving the peeling specifications of sea urchin seedlings, comprising the following steps: (1) inoculating Oscillatoria onto the front of a bait plate, and inoculating Oscillatoria onto the back of the bait plate the next day, and allowing the Oscillatoria to stand and cultivate; (2) inoculating benthic diatoms onto the front of the bait plate that has been inoculated with Oscillatoria, and inoculating benthic diatoms onto the back of the bait plate that has been inoculated with Oscillatoria the next day. The present invention first inoculates Oscillatoria on the bait plate, and then inoculates benthic diatoms, so that Oscillatoria can grow together with benthic diatoms on the bait plate. After the benthic diatoms are eaten to a certain extent by the sea urchin seedlings, suitable water temperature, light and nutritional conditions are provided to allow the Oscillatoria to grow rapidly, thereby meeting the bait needs of the sea urchin seedlings when they lack benthic diatoms, achieving a larger peeling specification, and even reaching a shell diameter of 4-5 mm, thereby ensuring the survival rate of the sea urchin seedlings after peeling.

Description

Technical Field

[0001] The invention relates to the technical field of sea treasure seedlings, and in particular to a method for improving the peeling specifications of sea urchin seedlings. Background Art

[0002] In the production of sea urchin seedlings, when the sea urchin planktonic larvae develop to the late stage of eight bowls, the sea urchin larvae need to be splashed into a nursery pond equipped with open bait plates to continue cultivation. The open bait for sea urchin larvae is mostly benthic diatoms. The benthic diatoms collected in the sea area or the benthic diatoms kept by the company themselves are inoculated into polyethylene bait plates in baskets. They are generally cultivated for about 30-50 days and transferred to new nursery ponds as the open bait for sea urchin larvae. The sea urchin larvae in the late stage of eight bowls are splashed into the nursery pond, attached to the open bait plates, and open to feed in about 8 days (different sea urchin species, cultivated under different water temperature conditions, have different opening feeding times for sea urchin larvae). Before the benthic diatom bait on the open bait plate is eaten up by the sea urchin larvae, the sea urchin seedlings are stripped from the benthic diatom bait plate, transferred to a net cage, and fed with large algae for breeding. Generally, when stripped, the sea urchin specifications are 2-3mm in shell diameter. The larger the size of the sea urchin larvae when peeled, the higher their survival rate will be after they are peeled and transferred to the cage to feed on large bait.

[0003] To increase the size of sea urchin fry during peeling, some nursery technicians place a new open bait plate containing benthic diatoms on a bait plate that is nearly depleted of benthic diatoms. This is called a "leaning plate." The urchin fry then climb onto the new bait plate and continue feeding on the benthic diatoms. Once the benthic diatoms on the new bait plate are completely consumed, the fry are peeled off again. This procedure allows the fry to reach approximately 4 mm in size during peeling, significantly improving survival rates. However, this requires increasing the number of benthic diatom bait plates, requiring more labor and more incubation tanks, increasing nursery costs, and reducing the efficiency of nursery facilities. Some nursery producers also increase the incubation time of benthic diatom bait, thereby increasing the biomass of the benthic diatom bait, thereby increasing the time the urchin larvae spend feeding on the benthic diatom bait and improving peeling size. However, this method results in an excessively large and aged benthic diatom biomass when the larvae are poured into the pond. This makes it difficult for the newly poured larvae to attach, reducing the rate of attachment. Furthermore, the already attached larvae are more likely to turn pale and die due to a lack of access to the small-sized benthic diatom bait on the bottom. Therefore, an economical and effective method for increasing the size of larvae peeled from open bait plates is urgently needed in sea urchin seedling production. Summary of the Invention

[0004] In view of the above-mentioned prior art, the object of the present invention is to provide an economical and effective method for improving the peeling specifications of sea urchin seedlings.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for improving the peeling specifications of sea urchin seedlings, comprising the following steps:

[0007] (1) Inoculate the front of the bait plate with Oscillatoria algae and perform the first aeration. The next day, inoculate the back of the bait plate with Oscillatoria algae and perform the second aeration. Let it sit and cultivate.

[0008] (2) Inoculate benthic diatoms onto the front of the bait board that has been inoculated with Oscillatoria, perform the first aeration, and the next day inoculate benthic diatoms onto the back of the bait board that has been inoculated with Oscillatoria, perform the second aeration, let it sit for cultivation, stand the basket, add foam, and perform normal cultivation;

[0009] (3) Eight bowls of late-stage sea urchin larvae are poured into the nursery pond equipped with bait plates inoculated with benthic diatoms and Oscillatoria, and cultured normally. When the benthic diatoms on the open bait plates are eaten by sea urchin larvae to an area of ​​1 / 3-1 / 2, the culture conditions are adjusted to allow the Oscillatoria to grow rapidly. When the sea urchin seedlings have eaten all the benthic diatoms and Oscillatoria, the sea urchin seedlings are peeled off and transferred to the cage for feeding.

[0010] Preferably, in step (1), the first and second inflation times are both 10-15 minutes, and the inoculation density of Oscillatoria on the front and back sides of the bait plate is 0.8-1.6 g / m 2 ; The static cultivation time is 2 days; the light intensity during the inoculation and static period of Oscillatoria is 800-1100lx, the daily light intensity is 8-14h, and the temperature is 18-25℃; nutrients are added before the positive inoculation of Oscillatoria, including 10ppm sodium nitrate, 2ppm potassium dihydrogen phosphate, and 1ppm ammonium ferric citrate.

[0011] Preferably, in step (1), the method for obtaining Oscillatoria is as follows: adding sand-filtered seawater to a culture bottle, heating it to a boil and then keeping it for 1-5 minutes, cooling it to room temperature, adding nutrient salts to the culture bottle, the nutrient salts including 10 ppm sodium nitrate, 2 ppm potassium dihydrogen phosphate, and 1 ppm ammonium ferric citrate; crushing the Oscillatoria algae with a 260-mesh sieve, rinsing the sieve with sand-filtered seawater to obtain an algae liquid, inoculating the Oscillatoria algae into the culture bottle at an inoculation rate of 2 g / bottle of the Oscillatoria algae before crushing, and culturing the Oscillatoria algae at a temperature of 18-25°C, a light intensity of 800-1100 lx, and a daily light intensity of 8-14 hours for 2-3 weeks, forming a layer of Oscillatoria algae film on the surface of the seawater in the culture bottle, collecting the algae film, crushing it with a 260-mesh sieve, diluting the obtained Oscillatoria algae liquid with sand-filtered seawater, and inoculating it onto a bait plate.

[0012] Preferably, in step (2), the first and second inflation times are both 10-15 minutes, and the inoculation density of benthic diatoms on the front and back sides of the bait plate is 8-16 g / m 2; The static incubation time is 2 days; the incubation conditions during inoculation and static period are 2000-3000lx of light, 8-14h of light per day, and a temperature of 18-25°C; nutrients are added before the positive inoculation of benthic diatoms, including 5ppm of sodium nitrate, 0.5ppm of potassium dihydrogen phosphate, 1ppm of sodium silicate pentahydrate, and 0.1ppm of ammonium ferric citrate.

[0013] Preferably, in step (2), the normal cultivation time is 30-45 days, the normal cultivation conditions are illumination 1500-3500 Lux, daily illumination time 8-14 h, natural water temperature, half amount of running water every day, and 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate are added after running water.

[0014] Preferably, in step (2), the method for obtaining benthic diatom species is as follows: the bait plate with benthic diatoms is removed from the breeding water body and drained, the benthic diatoms on the front and back of the bait plate are scrubbed into a basin of water to obtain a benthic diatom liquid, the benthic diatom liquid is filtered through a 260-mesh silk sieve, and then filtered through a 300-mesh silk sieve, and the obtained benthic diatom liquid is inoculated onto the bait plate obtained in step (1).

[0015] Preferably, in step (3), the normal cultivation conditions are a light intensity of 1000-5000 Lux, a daily light intensity of 8-14 hours, a water temperature of 16-20°C, a water flow of 1 times per day, and 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate are added after the water flow; when the area of ​​benthic diatoms eaten by sea urchin larvae reaches 1 / 3-1 / 2, the cultivation conditions are adjusted to a temperature of 18-20°C, a light intensity of 800-1100 lx, a daily light intensity of 8-14 hours, and nutrient salts are applied after the water flow every day: 2 ppm of sodium nitrate, 0.4 ppm of potassium dihydrogen phosphate, and 0.2 ppm of ammonium ferric citrate.

[0016] When inoculated on a sea urchin larval feed plate, Oscillatoria can rapidly grow under conditions of 800-1100 lx, a water temperature of 18-25°C, and suitable nutrient levels. Oscillatoria is not a primary feed for sea urchin larvae, and compared to benthic diatoms, it is also not a palatable food for them. However, when sea urchin larvae grow to a shell diameter of 1 mm or larger and no palatable benthic diatoms are available, they will consume Oscillatoria. If both Oscillatoria and benthic diatoms are co-inoculated on a sea urchin feed plate, the Oscillatoria can meet the larval urchin's feeding requirements when the benthic diatoms on the plate are insufficient, thereby improving the size of the urchin seedlings.

[0017] Beneficial effects of the present invention:

[0018] The present invention first inoculates Oscillatoria on the bait plate, and then inoculates benthic diatoms. Oscillatoria can grow together with benthic diatoms on the bait plate. Oscillatoria is inoculated before benthic diatoms, and given suitable growth conditions, Oscillatoria first attaches and grows on the bait plate. However, under the conditions of conventional culture of benthic diatoms, the Oscillatoria does not have a competitive advantage, but it does not die either. After inoculation of benthic diatoms, it will be covered by benthic diatoms. When the benthic diatoms are eaten to a certain extent by the sea urchin seedlings, the Oscillatoria is given suitable water temperature, light and nutritional conditions, and grows rapidly to meet the bait needs of the sea urchin seedlings when there are no benthic diatoms, reaching a larger peeling specification, and even reaching a shell diameter of 4-5mm, to ensure the survival rate of the sea urchin seedlings after peeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 : After inoculating oscillatoria and benthic diatoms in the embodiment, the bait plate was cultivated for 5 days;

[0020] Figure 2 : After inoculating oscillatoria and benthic diatoms in the embodiment, the bait plate was cultivated for 15 days;

[0021] Figure 3 : After inoculating oscillatoria and benthic diatoms in the embodiment, the bait plate was cultivated for 25 days;

[0022] Figure 4 : After inoculating oscillatoria and benthic diatoms in the embodiment, the bait plate was cultivated for 35 days;

[0023] Figure 5 : In comparative example 1, after inoculation with benthic diatoms, the bait plate was cultivated for 35 days;

[0024] Figure 6 : The bait board after 62 days of normal cultivation of benthic diatoms in comparative example 1

[0025] Figure 7 : Eight bowls of late-stage sea urchin larvae splashed in the Examples and Comparative Examples;

[0026] Figure 8 : In Comparative Example 1, accumulation of whitish dead sea urchin larvae occurred in the furrows of the bait plate. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0028] As described in the background technology, in order to increase the peeling specifications of sea urchin larvae on the benthic diatom bait board, in the existing technology, a new bait board "leaning board" is used, which will consume more manpower and benthic diatom bait boards, and increase the cost of seedling cultivation; if the benthic diatom culture time is increased and the benthic diatom biomass is increased, the benthic diatoms will age, which will make it difficult for the eight bowls of late-stage sea urchin larvae that have just been sprinkled to attach, and the seedling attachment rate will be reduced. At the same time, the sea urchin larvae that have already attached are also prone to turn white and die because they cannot eat the small benthic diatom bait on the bottom layer.

[0029] Based on this, the present invention provides a method for improving the peeling specifications of sea urchin seedlings on an open bait plate, comprising the following steps:

[0030] (1) Inoculate the Oscillatoria algae on the front of the bait plate and aerate for 10-15 minutes. The next day, inoculate the Oscillatoria algae on the back of the bait plate and aerate for 10-15 minutes. The inoculation density of the Oscillatoria algae on both the front and back of the bait plate is 0.8-1.6 g / m 2 , and cultured statically for 2 days; the light intensity during the inoculation and static period of Oscillatoria is 800-1100lx, the daily light duration is 8-14h, and the temperature is 18-25℃; nutrients are added before the positive inoculation of Oscillatoria, including 10ppm sodium nitrate, 2ppm potassium dihydrogen phosphate, and 1ppm ammonium ferric citrate.

[0031] Method for obtaining Oscillatoria: add sand-filtered seawater into a culture bottle, boil it and keep it for 1-5 minutes, cool it to room temperature, add nutrients into the culture bottle, the nutrients include 10ppm sodium nitrate, 2ppm potassium dihydrogen phosphate, and 1ppm ammonium ferric citrate; crush the Oscillatoria species with a 260-mesh sieve, rinse the sieve with sand-filtered seawater to obtain algae liquid, inoculate it into the culture bottle according to the inoculation amount of 2g / bottle of Oscillatoria species before crushing, and culture it at a temperature of 18-25℃, 800-1100lx of light, and 8-14h of light per day for 2-3 weeks. A layer of Oscillatoria film will form on the surface of the seawater in the culture bottle. Collect the algae film, crush it with a 260-mesh sieve, dilute the obtained Oscillatoria liquid with sand-filtered seawater, and inoculate it onto the bait plate.

[0032] (2) Inoculate benthic diatoms onto the front of the bait board that has been inoculated with Oscillatoria, and perform the first aeration for 10-15 minutes. The next day, inoculate benthic diatoms onto the back of the bait board that has been inoculated with Oscillatoria, and perform the second aeration for 10-15 minutes. The inoculation density of benthic diatoms on both the front and back of the bait board is 8-16 g / m 2The culture is incubated for 2 days. During the inoculation and incubation period, the incubation conditions are 2000-3000 lux of light, 8-14 hours of light per day, and a temperature of 18-25°C. Nutrients are added before inoculation of benthic diatoms, including 5 ppm sodium nitrate, 0.5 ppm potassium dihydrogen phosphate, 1 ppm sodium silicate pentahydrate, and 0.1 ppm ammonium ferric citrate. The baskets are upright and foamed. The normal incubation period is 30-45 days. Normal incubation conditions are 1500-3500 lux of light, 8-14 hours of light per day, and natural water temperature. Half the water is run daily. After the run, 1 ppm sodium nitrate, 0.1 ppm potassium dihydrogen phosphate, 0.02 ppm sodium silicate pentahydrate, and 0.05 ppm ammonium ferric citrate are added.

[0033] Method for obtaining benthic diatoms: remove the benthic diatom bait board from the breeding water body and drain it, scrub the benthic diatoms on the front and back of the bait board into a basin of water to obtain a benthic diatom liquid, filter the benthic diatom liquid through a 260-mesh silk sieve, and then filter it through a 300-mesh silk sieve, and inoculate the obtained benthic diatom liquid onto the bait board obtained in step (1);

[0034] (3) Eight bowls of late-stage sea urchin larvae were poured into a nursery pond inoculated with benthic diatoms and oscillators and cultured normally. The normal culture conditions were: 1000-5000 Lux, 8-14 hours of light per day, water temperature: 16-20°C, 1-fold water flow per day, and 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate added after the water flow. When the benthic diatoms on the open bait plate were consumed by the sea urchin larvae to the extent of 1 / 3-1 / 2, the culture conditions were adjusted to 18-20°C, 800-1100 Lux, 8-14 hours of light per day, and 2 ppm of sodium nitrate, 0.4 ppm of potassium dihydrogen phosphate, and 0.2 ppm of ammonium ferric citrate added before the water flow. When the sea urchin larvae had consumed all the benthic diatoms and oscillators, the sea urchin larvae were peeled and transferred to a cage for feeding.

[0035] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to specific embodiments.

[0036] The test materials used in the examples of the present invention are all conventional test materials in the art and can be purchased through commercial channels.

[0037] Example

[0038] (1) Add 4 L of sand-filtered seawater to each of 12 5 L conical flasks. Cover the flasks with filter paper and seal them with a rubber band, leaving a corner of the filter paper at the flask mouth for air to escape. Boil the seawater on an electric ceramic stove for 3 minutes and then cool to room temperature. Add nutrient salts to the conical flasks: 10 ppm sodium nitrate, 2 ppm potassium dihydrogen phosphate, and 1 ppm ammonium ferric citrate. Weigh 24 g of Oscillatoria algae membrane, crush it with a 260-mesh sieve, divide it into 12 equal portions, and inoculate them into 12 conical flasks. Incubate at 20°C, 1000 lx light, and 12 h of light per day for 2 weeks. Oscillatoria algae will form a layer of algae membrane on the surface of the liquid in the conical flasks.

[0039] (2) Add 4 tons of sand-filtered seawater at 23°C to a 5-ton aeration tank. Place 840 polyethylene bait boards (40 cm x 33 cm) horizontally in the tank. Add the following nutrients: 10 ppm sodium nitrate, 2 ppm potassium dihydrogen phosphate, and 1 ppm ammonium ferric citrate.

[0040] (3) Collect 110 g of Oscillatoria membranes from 6 conical flasks, crush them with a 260-mesh silk sieve, dilute to 10 L with sand-filtered seawater, and sprinkle them into the nursery pond to inoculate on the front of the bait plate. Aerate for 15 minutes. The next day, turn the bait plate over in the nursery pond, collect 115 g of Oscillatoria membranes from another 6 conical flasks, crush them with a 260-mesh silk sieve, and inoculate on the back of the bait plate. Aerate for 15 minutes and let it sit for 2 days. During the inoculation and rest period, the light intensity was 1000 lx, and the light duration was 12 h per day.

[0041] (4) Take a large plastic basin, place a sponge in it, and fill it with sand-filtered seawater. Weigh 3000 g. Use the sponge to wipe the old benthic diatoms from the opposite sides of 50 bait boards into the large plastic basin. Allow the bait boards to drain for 3 minutes before wiping. After the benthic diatoms are wiped in, the basin weighs 3510 g. Collect 510 g of benthic diatoms. Filter the algae solution using 260-mesh and 300-mesh sieves, respectively, to remove large benthic diatoms and debris.

[0042] Add nutrient salts to the cultivation pond: 5ppm sodium nitrate, 0.5ppm potassium dihydrogen phosphate, 1ppm sodium silicate pentahydrate, 0.1ppm ammonium ferric citrate, and the water temperature is 22.5°C. Sprinkle the benthic diatoms evenly into the seedling pond after inoculating the oscillatoria in step (3) and letting it stand for 2 days, and aerate for 15 minutes. The next day, turn the bait board over, and inoculate 495g of benthic diatoms from another 50 bait boards on the other side of the bait board, aerate for 15 minutes, and let it stand for 2 days. During the inoculation and standing period of the benthic diatoms, the light intensity is 2500lx, and the light intensity is 12h per day.

[0043] (5) After 2 days of static cultivation, the baskets were erected, foamed, and cultivated normally for 35 days. The cultivation conditions were 1500-3500 Lux, 10-14 hours of light per day, natural water temperature, and half-flow water per day. After the flow, 1 ppm sodium nitrate, 0.1 ppm potassium dihydrogen phosphate, 0.02 ppm sodium silicate pentahydrate, and 0.05 ppm ammonium ferric citrate were added. In the early stage of inoculation of benthic diatoms, many Oscillatoria were visible on the corrugated board. After 35 days of cultivation, very few Oscillatoria were visible on the surface of the corrugated board, and it was almost completely covered by benthic diatoms.

[0044] Figure 1 In order to inoculate Oscillatoria and benthic diatoms, the corrugated plate was cultivated normally for 5 days. It can be seen that there are still many Oscillatoria on the corrugated plate. Figure 2 The corrugated plate was inoculated with Oscillatoria and benthic diatoms after 15 days of normal cultivation. It can be seen that the proportion of Oscillatoria on the corrugated plate is significantly reduced. The arrow points to Oscillatoria. Figure 3 To inoculate Oscillatoria and benthic diatoms, a small amount of Oscillatoria can be seen on the corrugated plate after 25 days of normal cultivation. Figure 4 In order to inoculate Oscillatoria and benthic diatoms, the corrugated plate was cultivated normally for 35 days. It can be seen that there are very few Oscillatoria on the corrugated plate.

[0045] (6) The bait basket in the nursery pond was transferred to a new nursery pond, and eight bowls of 2.8 million late-stage sea urchin larvae were sprinkled therein. The larvae were cultured and managed normally under the following conditions: an illumination of 1000-4500 Lux, a daily illumination time of 10-14 h, a water temperature of 17-18°C, and a water flow rate of 1 times per day. 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate were added to the water after the water flow;

[0046] After seven days of larval sea urchins being added to the pond, some began to feed. By 24 days, some had reached a shell diameter of nearly 2mm. Two-fifths of the benthic diatoms on the corrugated plate had been consumed by the urchins, and oscillators were visible where the benthic diatoms had been consumed. The water temperature was adjusted to 18-20°C, and nutrients were applied daily after the water was drained: 2ppm sodium nitrate, 0.4ppm potassium dihydrogen phosphate, and 0.2ppm ammonium ferric citrate. Light intensity was 800-1100lx, with a daily photoperiod of 12-14 hours.

[0047] Oscillatoria rapidly grew in areas of the corrugated board where benthic diatoms had been consumed. Forty days after the larval sea urchins were splashed into the pond, the urchin fry had almost completely consumed the benthic diatoms and oscillatoria on the boards. The urchin fry were then stripped, leaving an average of 332 urchins per board, with an average shell diameter of 4.2 mm. 289 urchin fry, or 87%, had shells larger than 4 mm. These fry were then transferred to cages for rearing.

[0048] Comparative Example 1

[0049] (1) Add 4 tons of sand-filtered seawater to a 5-ton aeration tank at 23°C. Place 840 polyethylene bait boards (40 cm x 33 cm) horizontally in the tank. Add the following nutrients to the tank: 5 ppm sodium nitrate, 0.5 ppm potassium dihydrogen phosphate, 1 ppm sodium silicate pentahydrate, and 0.1 ppm ammonium ferric citrate.

[0050] (2) Take a large plastic basin, put a sponge in it, fill it with sand-filtered seawater, and weigh 2950g. Use a sponge to wipe the old benthic diatom species on the reverse side of 50 corrugated plates of bait into the large plastic basin. Control the water for 3 minutes before wiping the corrugated plates. After wiping in the benthic diatoms, the large basin weighs 3450g. Obtain 500g of benthic diatoms. Use 260-mesh and 300-mesh sieves to filter out large benthic diatoms and debris in the algae liquid. Sprinkle the benthic diatom species evenly into the nursery pond at a water temperature of 23°C. Inflate for 15 minutes. The next day, turn the corrugated plate frame over and inoculate 510g of the old benthic diatom species on another 50 corrugated plates on the other side of the corrugated plate. Inflate for 15 minutes and let it stand for 2 days. During the inoculation and standing period of the benthic diatoms, the light intensity is 2500lx, and the light duration is 12h per day.

[0051] (3) After 2 days of static cultivation, the baskets were erected, foam was removed, and normal cultivation management began. The cultivation conditions were 1500-3500 Lux, 10-14 hours of light per day, natural water temperature, and half-flow of water per day. After the flow, 1 ppm sodium nitrate, 0.1 ppm potassium dihydrogen phosphate, 0.02 ppm sodium silicate pentahydrate, and 0.05 ppm ammonium ferric citrate were added. After 62 days of cultivation, the surface of the corrugated board was covered with dark brown benthic diatoms.

[0052] Figure 6 The corrugated plate is inoculated with benthic diatoms after 62 days of normal cultivation. It can be seen that there is no Oscillatoria on the corrugated plate, and the benthic diatoms are numerous, thick and dark in color.

[0053] (5) The bait basket in the nursery pond was transferred to a new nursery pond, and eight bowls of 2.8 million late-stage sea urchin larvae were sprinkled therein. The larvae were cultured and managed normally under the following conditions: an illumination of 1000-4500 Lux, a daily illumination time of 10-14 h, a water temperature of 17-18°C, and a water flow rate of 1 times per day. 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate were added to the water after the water flow;

[0054] Eight days after the larvae were added to the pond, some of them began to eat. On the 17th day, a pile of dead larvae appeared in the furrows of the bait board. Figure 7After 24 days of cultivation, about one-fifth of the benthic diatoms on the bait plate had been consumed, and the shell diameter of some sea urchin larvae reached nearly 2 mm. By the 39th day, the sea urchin fry had consumed most of the benthic diatoms on the bait plate, and the sea urchin fry were peeled off. On average, there were 223 sea urchin fry per corrugated plate, with an average shell diameter of 4.1 mm. There were 177 sea urchin fry with a shell diameter of more than 4 mm, accounting for 79%. The sea urchin fry were then transferred to cages for rearing.

[0055] Comparative Example 2

[0056] (1) Add 4 tons of sand-filtered seawater to each of two 5-ton aeration tanks (A and B), each at 22°C. Place 840 sheets of polyethylene corrugated sheet material (40 cm x 33 cm) in each tank. Add the following nutrients to the tanks: 5 ppm sodium nitrate, 0.5 ppm potassium dihydrogen phosphate, 1 ppm sodium silicate pentahydrate, and 0.1 ppm ammonium ferric citrate.

[0057] (2) Take a large plastic basin, put a sponge in it, fill it with sand-filtered seawater, and weigh 3060g. Use a sponge to wipe the old benthic diatom species on the reverse side of 100 corrugated plates into the large plastic basin. Control the water for 3 minutes before wiping the corrugated plates. After wiping in the benthic diatoms, the large basin weighs 4100g. Obtain 1040g of benthic diatoms. Use 260-mesh and 300-mesh sieves to filter out large benthic diatoms and debris in the algae liquid. Divide the benthic diatom species into 2 parts, and evenly sprinkle each part into a nursery pond with a water temperature of 22℃. After aeration for 15 minutes, let it stand and cultivate for 1 day. Turn the corrugated plate frame over and inoculate 1070g of the old benthic diatom species on another 100 corrugated plates on the other side of the corrugated plate. The operation is the same as above. Aerate for 15 minutes, let it stand and cultivate for 2 days, with a light intensity of 2500lx and a light intensity of 12h per day.

[0058] (3) After 2 days of static cultivation, the baskets were erected, foam was added, and normal cultivation management was performed. The cultivation conditions were 1500-3500 Lux of light, 10-14 hours of light per day, natural water temperature, half of the water flowed every day, and 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate were added after the water flowed.

[0059] (4) After 35 days, the benthic diatoms in pool A were cultured under the original conditions of the original pool. The bait baskets in the nursery pool B were transferred to a new nursery pool, and eight bowls of 2.8 million late-stage sea urchin larvae were sprinkled. Normal culture and management were carried out under the following conditions: a light intensity of 1000-4500 Lux, a light duration of 10-14 h per day, a water temperature of 17-18 °C, and a water flow rate of 1 times per day. After the water flow, 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate were added.

[0060] Seven days after the larvae were added to the pond, some began feeding. By day 28, approximately four-fifths of the benthic diatoms on the bait plates had been consumed. The bait plates in Pool A, which had been incubated for 63 days, were attached one by one to bait plates nearing the end of their benthic diatoms. The sea urchin fry climbed onto the new bait plates and continued feeding. By day 39, the fry had consumed most of the benthic diatoms on the bait plates. The fry were peeled off, revealing an average of 329 juvenile sea urchins per corrugated plate, with an average shell diameter of 4.2 mm. 283 fry, representing 86% of the total, had shell diameters exceeding 4 mm. The fry were then transferred to cages for rearing.

[0061] The results of the examples are compared with two existing methods for improving the peeling specifications of sea urchins. Comparative Example 1 is a method of increasing the bait culture time to increase the biomass, and Comparative Example 2 is a board-based method.

[0062] Comparison table of index data of examples and comparative examples

[0063]

[0064] The results show that compared with Comparative Example 1, the following: The average shell diameter of juvenile sea urchins in the Example showed no significant difference; the average number of juvenile sea urchins per bait plate increased by 48.9%, significantly improving yield; the number of juvenile sea urchins with a shell diameter of 4 mm or larger increased by 63.2%, with a significant increase in the number of large-sized juveniles; and the proportion of juvenile sea urchins with a shell diameter of 4 mm or larger on the bait plate relative to the total juvenile sea urchins increased by 8 percentage points. Therefore, the method of cultivating a mixed bait of benthic diatoms and oscillatoria in the present invention has significant advantages over the method of increasing bait biomass in Comparative Example 1.

[0065] Compared with Comparative Example 2, the present invention showed no significant improvement in the average number of juvenile sea urchins per bait plate, juvenile shell diameter, number of juvenile sea urchins with a shell diameter of 4 mm or larger, and the proportion of juvenile sea urchins with a shell diameter of 4 mm or larger to the total number of juvenile sea urchins on the bait plate. However, the results for each indicator were comparable to those of Comparative Example 2. However, the present invention significantly improved facility utilization and reduced labor costs compared to the method of Comparative Example 2, resulting in significantly better efficiency. Comparative Example 2 required twice as many bait plates as the present invention, requiring twice as many culture tanks and twice as many workers to cultivate the bait. Furthermore, additional labor was required to maintain the plates. Therefore, the present invention significantly improved work efficiency and production benefits.

[0066] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for improving the peeling specifications of sea urchin seedlings, characterized in that: The following steps are involved: (1) First add oscillatoria nutrient salt, then add oscillatoria at a rate of 0.8-1.6g / m 2 Inoculate the bait plate at a density of 0.8-1.6 g / m2 and aerate for 10-15 minutes. 2 Inoculate the reverse side of the bait plate with a density of 100 μg / ml, aerate for 10-15 minutes, and incubate for 2 days. (2) First add benthic diatom nutrient salt, then add benthic diatoms at 8-16g / m 2 Inoculate the bait plate on the front of the bait plate that has been inoculated with Oscillatoria algae at a density of 8-16 g / m 2 Inoculate at the opposite side of the bait plate that has been inoculated with Oscillatoria algae, aerate for 10-15 minutes, let it sit for 2 days, stand the basket upright, add foam, and then continue normal cultivation. (3) Eight bowls of late-stage sea urchin larvae are poured into a nursery pond equipped with a bait plate inoculated with benthic diatoms and oscillators, and cultured normally. When the benthic diatoms on the bait plate are consumed by the sea urchin larvae to an area of ​​1 / 3-1 / 2, the culture conditions are adjusted to allow the oscillators to grow rapidly. When the sea urchin larvae have consumed all the benthic diatoms and oscillators, the sea urchin larvae are peeled off and transferred to a cage for feeding; In step (1), the light intensity during the inoculation and standing period of the Oscillatoria is 800-1100 lx, the daily light duration is 8-14 hours, and the temperature is 18-25°C; in step (2), the cultivation conditions during the inoculation and standing period of the benthic diatoms are 2000-3000 lx, the daily light duration is 8-14 hours, and the temperature is 18-25°C.

2. A method for improving the peeling specifications of sea urchin seedlings according to claim 1, characterized in that: In step (1), the method for obtaining Oscillatoria is as follows: adding sand-filtered seawater to a culture bottle, heating it to a boil and then keeping it for 1-5 minutes, cooling it to room temperature, adding nutrient salts to the culture bottle, the nutrient salts including 10ppm sodium nitrate, 2ppm potassium dihydrogen phosphate, and 1ppm ammonium ferric citrate; crushing the Oscillatoria algae with a 260-mesh sieve, washing the sieve with sand-filtered seawater to obtain an algae liquid, inoculating the Oscillatoria algae into the culture bottle at an inoculation rate of 2g / bottle of the Oscillatoria algae before crushing, and culturing it at a temperature of 18-25°C, a light intensity of 800-1100lx, and a daily light intensity of 8-14h for 2-3 weeks, forming a layer of Oscillatoria algae film on the surface of the seawater in the culture bottle, collecting the algae film, crushing it with a 260-mesh sieve, diluting the obtained Oscillatoria algae liquid with sand-filtered seawater, and inoculating it onto a bait plate.

3. A method for improving the peeling specifications of sea urchin seedlings according to claim 1, characterized in that: In step (2), the normal cultivation time is 30-45 days, the normal cultivation conditions are light 1500-3500 Lux, daily light time is 8-14 hours, natural water temperature, half amount of water flow every day, and 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate are added after the water flow.

4. A method for improving the peeling specifications of sea urchin seedlings according to claim 1, characterized in that: In step (2), the method for obtaining benthic diatom species is as follows: the bait plate with benthic diatoms is removed from the breeding water body and drained, the benthic diatoms on the front and back of the bait plate are scrubbed into a basin of water to obtain a benthic diatom liquid, the benthic diatom liquid is filtered through a 260-mesh silk sieve, and then filtered through a 300-mesh silk sieve, and the obtained benthic diatom liquid is inoculated onto the bait plate obtained in step (1).

5. The method for improving the peeling specifications of sea urchin seedlings according to claim 1, characterized in that: In step (3), the normal cultivation conditions are: light intensity of 1000-5000 Lux, daily light intensity of 8-14 hours, water temperature of 16-20° C., 1 times the water flow per day, and 1 ppm of sodium nitrate, 0.1 ppm of potassium dihydrogen phosphate, 0.02 ppm of sodium silicate pentahydrate, and 0.05 ppm of ammonium ferric citrate added after the water flow; when the benthic diatoms are eaten by sea urchin larvae to a ratio of 1 / 3 to 1 / 2, the cultivation conditions are adjusted to a temperature of 18-20° C., light intensity of 800-1100 lx, daily light intensity of 8-14 hours, and nutrient salts of 2 ppm of sodium nitrate, 0.4 ppm of potassium dihydrogen phosphate, and 0.2 ppm of ammonium ferric citrate added after the water flow.

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