阅读说明：本技术 环保弹性填料在提高青蟹育苗成活率中的应用 (Application of environment-friendly elastic filler in improving survival rate of blue crab seedlings ) 是由 叶海辉 于 2021-09-15 设计创作，主要内容包括：本发明公开了环保弹性填料在提高青蟹育苗成活率中的应用,该环保弹性填料的材质为聚烯烃类材质或聚酰胺类材质,具有一中心绳,该中心绳上具有若干弹性丝条,该弹性丝条等间隔设于该中心绳上,且呈辐射状。本发明在青蟹育苗后期(大眼幼体至第3期仔蟹阶段,大约16天)的青蟹仔蟹培育池里悬挂特定结构的环保弹性填料,在培养生物膜净化水质的同时,能够为大眼幼体和仔蟹提供攀爬和隐蔽空间,减少自相残杀,提高存活率。(The invention discloses an application of an environment-friendly elastic filler in improving the survival rate of blue crab seedlings. According to the invention, the environment-friendly elastic filler with a specific structure is hung in the juvenile crab culture pond of the blue crabs at the later stage of the young crabs from the megalops to the 3 rd stage for about 16 days, so that a climbing and concealing space can be provided for the megalops and the juvenile crabs while the biomembrane is cultured to purify water quality, the mutual killing is reduced, and the survival rate is improved.)

1. The application of the environment-friendly elastic filler in improving the survival rate of the blue crab seedlings is characterized in that: the environment-friendly elastic filler is made of polyolefin materials or polyamide materials and is provided with a central rope, a plurality of elastic strands are arranged on the central rope at equal intervals and are radial.

2. The use of claim 1, wherein: the length of the central rope is 0.9-1.4m, the length of the elastic thread line is 120-180mm, and the diameter of the elastic thread line is 0.4-0.5 mm.

3. Use according to claim 2, characterized in that: the density of the elastic thread lines on the central rope is 3000-3200 threads/m.

4. Use according to any one of claims 1 to 3, characterized in that: when the daphnia larvae of the blue crabs just become megalops, a plurality of lacing lines are pulled on the young blue crab culture pond, one end of the environment-friendly elastic filler is connected to the lacing lines, and the other end of the environment-friendly elastic filler is connected with a pendant, so that the environment-friendly elastic filler is suspended in the water body of the young blue crab culture pond and is uniformly distributed until the seedling culture is finished.

5. The use of claim 4, wherein: the suspension amount of the environment-friendly elastic filler is 10-15 strips/m²。

6. A method for improving the survival rate of the blue crab seedlings is characterized in that: when the daphnia larvae of the blue crabs just become megalops, pulling a plurality of lacing lines on the young blue crab culture pond, connecting one end of the environment-friendly elastic filler to the lacing lines, and connecting the other end of the environment-friendly elastic filler with a pendant to enable the environment-friendly elastic filler to be suspended in the water body of the young blue crab culture pond and to be uniformly distributed until the seedling culture is finished;

the environment-friendly elastic filler is made of polyolefin materials or polyamide materials and is provided with a central rope, a plurality of elastic strands are arranged on the central rope at equal intervals and are radial.

7. The method of claim 6, wherein: the length of the central rope is 0.9-1.4m, the length of the elastic thread line is 120-180mm, and the diameter of the elastic thread line is 0.4-0.5 mm.

8. The method of claim 7, wherein: the density of the elastic thread lines on the central rope is 3000-3200 threads/m.

9. The method of any one of claims 6 to 8, wherein: the suspension amount of the environment-friendly elastic filler is 10-15 strips/m²。

10. The method of claim 9, wherein: the water temperature in the blue crab larva breeding pool is 29-32 ℃, the salinity is 22-25, the pH is 8.0-8.5, the dissolved oxygen is more than 5mg/L, the water is changed for 1-2 times every day, and the water change amount is 50-80%.

Technical Field

The invention belongs to the technical field of blue crab breeding, and particularly relates to application of an environment-friendly elastic filler in improving the survival rate of blue crab seedling.

Background

Scylla paramamosain (Scylla paramamosain) is a warm water-based marine crab, is widely distributed in the sea area of the south of the Yangtze estuary in China, is also an important cultivated crab in the south of China, and has the annual cultivation yield of 15 ten thousand tons and the yield value of more than 200 ten thousand yuan. The young blue crabs are mainly obtained by fishing in sea areas, and the proportion of artificial young crabs is less than 5 percent. At present, the rate of emergence of artificial seedlings is low (the rate of emergence is about 5%), seedling enterprises are difficult to profit, and practitioners are few. Long-term past, the method is not beneficial to the healthy development of the blue crab industry.

The development of the young blue crab comprises daphnia larvae and megalopas, and generally takes 22-23 days. After the megalops finishes metamorphosis, the megalops develops into the juvenile crab of the 1 st stage. The artificial young blue crab is stage 1-3 young crab, and the stage lasts for about 10 days. The larval vision is sharp, the chela is developed, the swimming is rapid, the larval is frequently clustered and killed mutually, and the survival rate of the larval is seriously influenced. When the megalopas are transformed into juvenile crabs, the living conditions of the megalopas are transformed from swimming to demersal, and the requirements of the megalopas and juvenile crabs on the attached and concealed space are rapidly increased. If the required space and area are insufficient, the fry emergence amount of the juvenile crabs is seriously influenced. Therefore, it is very important to provide sufficient and proper attachment facilities in the later stage of young blue crab cultivation (megalopa and young crab stage). In the stage of megalopa and young crab, the common attaching facilities are oyster shell and net sheet. The surface of the oyster shell is uneven and has a plurality of gaps, and the suspended oyster shell can provide hiding and protecting space for the larva. However, the weight of the oyster shell is large, the operation process is time-consuming and labor-consuming, and in addition, the oyster shell is not easy to purchase and seedling emergence is not thorough, so that the number of users is gradually reduced. At present, most practitioners adopt a method of hanging the mesh. The mesh is light and convenient, has low price and is easy to purchase and prepare. However, the hanging net has some disadvantages: for example, too large a mesh does not serve a concealing function, and too small a mesh allows insertion of juvenile appendages within the mesh, affecting locomotion and survival; the hanging net piece has an isolation effect, and the larva is isolated in a specific area, so that the activity of the larva in the whole blue crab larva breeding pond is not facilitated. Therefore, further development and production of seed-adhering facilities is needed. In addition, in the whole fry breeding process, with the increase of food residues, excrement and the like, organic matters in the juvenile crab breeding pond gradually accumulate, and particularly in the later period of breeding, the concentration of ammonia nitrogen is high, a large number of harmful bacteria are bred, the ecosystem is unbalanced, and the success rate of breeding is seriously influenced. Therefore, in the later stage of the blue crab breeding, effective attaching facilities need to be provided, and meanwhile, a good water quality environment needs to be maintained, which is an indispensable technical measure for successful breeding.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the application of the environment-friendly elastic filler in improving the survival rate of the blue crab seedlings.

The invention also aims to provide a method for improving the survival rate of the young blue crabs.

The technical scheme adopted by the invention is as follows:

the application of the environment-friendly elastic filler in improving the survival rate of the blue crab seedlings is characterized in that the environment-friendly elastic filler is made of polyolefin materials or polyamide materials and is provided with a central rope, a plurality of elastic strands are arranged on the central rope, and the elastic strands are arranged on the central rope at equal intervals and are radial.

In a preferred embodiment of the present invention, the length of the central cord is 0.9 to 1.4m, the length of the elastic strand is 120-180mm, and the diameter is 0.4 to 0.5 mm.

More preferably, the density of the elastic threads on the central rope is 3000-3200 threads/m.

In a preferred embodiment of the invention, when the daphnia larvae of the blue crabs just become megalops, a plurality of lacing lines are pulled on the young blue crab culture pond, one end of the environment-friendly elastic filler is connected to the lacing lines, and the other end of the environment-friendly elastic filler is connected with a pendant, so that the environment-friendly elastic filler is suspended in the water body of the young blue crab culture pond and uniformly distributed until the seedling culture is finished.

Further preferably, the suspension amount of the environment-friendly elastic filler is 10-15 strips/m²。

The other technical scheme of the invention is as follows:

a method for improving the survival rate of young blue crabs in seedling culture comprises the steps that when daphnia-shaped larvae of the blue crabs are just transformed into megalops, a plurality of lacing lines are pulled on a young blue crab culture pond, one end of environment-friendly elastic filler is connected to the lacing lines, the other end of the environment-friendly elastic filler is connected with a pendant, and the environment-friendly elastic filler is suspended in a water body of the young blue crab culture pond and is uniformly distributed until the seedling culture is finished;

the environment-friendly elastic filler is made of polyolefin materials or polyamide materials and is provided with a central rope, a plurality of elastic strands are arranged on the central rope at equal intervals and are radial.

In a preferred embodiment of the present invention, the length of the central cord is 0.9 to 1.4m, the length of the elastic strand is 120-180mm, and the diameter is 0.4 to 0.5 mm.

More preferably, the density of the elastic threads on the central rope is 3000-3200 threads/m.

In a preferred embodiment of the present invention, the amount of the environmentally friendly elastic filler suspended is 10 to 15 strands/m²。

Further preferably, the water temperature in the blue crab larva breeding pool is 29-32 ℃, the salinity is 22-25, the pH is 8.0-8.5, the dissolved oxygen is more than 5mg/L, the water is changed for 1-2 times every day, and the water change amount is 50-80%.

The invention has the beneficial effects that:

1. according to the invention, the environment-friendly elastic filler with a specific structure is hung in the juvenile crab culture pond of the blue crabs at the later stage of the young crabs from the megalops to the 3 rd stage for about 16 days, so that a climbing and concealing space can be provided for the megalops and the juvenile crabs while the biomembrane is cultured to purify water quality, the mutual killing is reduced, and the survival rate is improved.

2. Compared with the method for hanging the net sheets, the method can effectively improve the indexes of ammonia nitrogen, chemical oxygen consumption, microorganism quantity and the like of the juvenile crab culture pond.

Drawings

FIG. 1 is a photograph of the environmentally friendly elastic filler in the present invention.

Detailed Description

The technical solution of the present invention will be further illustrated and described below with reference to the accompanying drawings by means of specific embodiments.

As shown in FIG. 1, the environmentally friendly elastic filler in the following examples is made of polyolefin or polyamide, and has a central cord with a plurality of elastic threads, which are arranged on the central cord at equal intervals and in a radial shape. The length of the central rope is 0.9-1.4m, the length of the elastic thread line is 120-180mm, the diameter is 0.4-0.5mm, and the density of the elastic thread line on the central rope is 3000-3200 threads/m.

Example 1

The productive breeding method of megalops and young crabs refers to CN101040606A. Wherein the density of the larval eye is about 5000 per m²Feeding copepods, adult artemia, minced fillet and the like, wherein the feeding amount is about 15% of the weight of the crab larvae, and feeding the baits once in the morning and at the evening according to the proportion of 3: 7. During seedling raising, water temperature is 29-32 deg.C, salinity is 22-25, pH is 8.0-8.5, dissolved oxygen is greater than 5mg/L, water is changed for 1-2 times every day, and water change amount is 50-80%.

The length, the width and the area of the blue crab larva breeding pond in the embodiment are 5m, 4m and 20m²When the water level for seedling is kept at 1.5m, and when the megalops are just appeared (namely when the daphnia larvae of the blue crabs are just transformed into the megalops), the lacing lines are arranged between every two rows of the air inflation pipes of the young blue crab culture pond, one end of the environment-friendly elastic filler is connected to the lacing lines, and the other end of the environment-friendly elastic filler is connected with a ceramic or lead pendant, so that the environment-friendly elastic filler is suspended in the water body of the young blue crab culture pond and is uniformly distributed. The length of the central rope of the environment-friendly elastic filler is 1.4m, and 300 ropes are hung in total. After 16 days of cultivation, the fry emergence amount of the juvenile crabs is 2720 crab/m²And the survival rate exceeds 54 percent. The diameter of the elastic filament in the environment-friendly elastic filler in the embodiment is 0.4mm, the length is 120mm, and the density of the elastic filament on the environment-friendly elastic filler is 3200 pieces/m.

Compared with the method for hanging the net (except for the hung materials, the other methods are the same as the embodiment, the net mesh is 60 meshes, the guy line is arranged between each row of the inflation pipes of the young blue crab culture pond, and the net (with the length of 4m and the width of 1m) is hung in the young blue crab culture pond), by using the method of the embodiment 1 of the invention, indexes such as ammonia nitrogen, chemical oxygen consumption, microbial quantity and the like of the young blue crab culture pond are superior to those of the method for hanging the net for comparison, and the specific method is shown in the following table 1:

TABLE 1. water quality change and microorganism quantity growth and degradation detection results of blue crab nursery

Note: the data above the same line is the detection result of the suspended net sheet, and the data below is the detection result of the suspended environment-friendly elastic filler.

The young crab seedling emergence amount is 2430 crab/m by using the method of hanging the net sheet²The survival rate is 48.6%. The method of the embodiment 1 of the invention is used, the fry emergence amount of the juvenile crabs is 2720 crab/m²The survival rate is 54.4%.

Example 2

For the productive breeding method of megalops and young crabs, CN101040606A is referred. The density of the larval eye is about 5000 per m²Feeding copepods, adult artemia, minced fillet and the like, wherein the feeding amount is about 15% of the weight of the crab larvae, and feeding the baits once in the morning and at the evening according to the proportion of 3: 7. During seedling raising, water temperature is 29-32 deg.C, salinity is 22-25, pH is 8.0-8.5, dissolved oxygen is greater than 5mg/L, water is changed for 1-2 times every day, and water change amount is 50-80%.

The area of the blue crab larva breeding pond in the embodiment is 50m²When the water level is kept at 1m and the megalops are just appeared (namely when the daphnia larvae of the blue crabs are just transformed into the megalops), the lacing lines are arranged between every two rows of the air inflation pipes of the young blue crab culture pond, one end of the environment-friendly elastic filler is connected to the lacing lines, and the other end of the environment-friendly elastic filler is connected with a ceramic or lead pendant, so that the environment-friendly elastic filler is suspended in the water body of the young blue crab culture pond and is uniformly distributed. The length of the central rope of the environment-friendly elastic filler is 0.9m, and 500 ropes are hung in total, so that the environment-friendly elastic filler is hung in the water body of the juvenile crab culture pond and is uniformly distributed. After 16 days of cultivation, the young crab seedling emergence amount is 2410 crab/m²And the survival rate exceeds 48 percent. The diameter of the elastic filament in the environment-friendly elastic filler in the embodiment is 0.5mm, the length is 150mm, and the density of the elastic filament on the environment-friendly elastic filler is 3000 pieces/m.

The method for hanging the net sheets is applied (except for different hanging materials, the other method is the same as the embodiment, the net sheets have the mesh size of 60 meshes, the net sheets (with the length of 4m and the width of 1m) are hung in the blue crab larva breeding pond through stay ropes between each row of the inflatable pipes of the blue crab larva breeding pond), and the larva crab emergence amount is 2000 crabs/m²The survival rate is 39.6%. By using the method of the embodiment 2 of the invention, the indexes of ammonia nitrogen, chemical oxygen consumption, microbial quantity and the like of the blue crab breeding pond are superior to those of the comparative suspended net piece method, and the fry emergence amount of the young crabs is2400/m²The survival rate is 48.1%.

The above description is only a preferred embodiment of the present invention, and therefore should not be taken as limiting the scope of the invention, which is defined by the appended claims.